BookPDF Available

A comparative morphological treatise of recent and fossil otoliths of the order Pleuronectiformes

January 1999

January 1999

DOI:10.13140/2.1.1725.5043

Edition: Piscium Catalogus. Otolithi Piscium, 2
Publisher: Verlag Dr. Friedrich Pfeil
Editor: Dr. Friedrich Pfeil
ISBN: 3-931516-54-7

Authors:

Content uploaded by Werner Schwarzhans

Content may be subject to copyright.

OTOLITHI PISCIUM

Werner SCHWARZHANS

A comparative morphological treatise

of recent and fossil otoliths

of the order Pleuronectiformes

Piscium

Catalogus

Edited by

Dr. Friedrich H. PFEIL

A continuing file of all recent and fossil fishes

from a paleoichthyological point of view

Edited by Dr. Friedrich H. PFEIL, München

Part OTOLITHI PISCIUM

Volume 2

Werner SCHWARZHANS

A comparative morphological treatise

of recent and fossil otoliths

of the order

Pleuronectiformes

Piscium

Catalogus

Verlag Dr. Friedrich Pfeil

München, April 1999

ISSN 0724-9012

ISBN 3-931516-54-7

Die Deutsche Bibliothek - CIP-Einheitsaufnahme

Schwarzhans, Werner:

A comparative morphological treatise of recent and fossil otoliths

of the order Pleuronectiformes / Werner Schwarzhans. - München : Pfeil, 1999

(Piscium catalogus : Pt. Otolithi piscium ; Vol. 2

ISBN 3-931516-54-7

Orders, manuscripts and commentaries should be addressed to

Redaktion PISCIUM CATALOGUS

Verlag Dr. Friedrich Pfeil

P.O. Box 65 00 86, D-81214 München

Tel. (089) 74 28 270 • Fax (089) 72 42 772 • E-Mail 100417.1722@compuserve.com

No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means,

electronic, mechanical, photocopying or otherwise, without the prior permission of the copyright owner.

Applications for such permission, with a statement of the purpose and extent of the reproduction, should be addressed

to the Publisher, Verlag Dr. Friedrich Pfeil, P.O. Box 65 00 86, D-81214 München.

Druckvorstufe: Verlag Dr. Friedrich Pfeil, München

CTP-Druck: grafik + druck GmbH Peter Pöllinger, München

Buchbinder: Thomas, Augsburg

ISSN 0724-9012

Printed in Germany

– Gedruckt auf chlorfrei gebleichtem und alterungsbeständigem Papier –

Verlag Dr. Friedrich Pfeil, P.O. Box 65 00 86, D-81214 München

Tel. (089) 74 28 270 • Fax (089) 72 42 772 • E-Mail 100417.1722@compuserve.com

Gedruckt mit Unterstützung der Deutschen Forschungsgemeinschaft

Piscium Catalogus: Part Otolithi piscium, Vol. 2, pp. 1-391, 1021 figs., April 1999

A comparative morphological treatise

of recent and fossil otoliths of the order Pleuronectiformes

Werner Schwarzhans*

Abstract

The following morphological study of otoliths of the order Pleuronectiformes (flatfishes) is the second part of a

long term catalogue project mainly dealing with recent otoliths. Amongst teleost groups of comparable size, the

otoliths of the order Pleuronectiformes are amongst the least well known. They are also not the easiest to work

with morphologically and have never been subject of a comprehensive analysis. Taxonomic work with

pleuronectiform otoliths is somewhat hampered by the often high degree of intraspecific variability, the low level

of interspecific morphological differentiation and of course the ubiquitous effects of asymmetry.

For this treatise I have investigated otoliths of more than 300 recent species of the Pleuronectiformes (corre-

sponding to more than 50 % of the known recent species of the order) covering 116 genera of the 133 currently

recognized. In addition, the 124 nominal fossil otolith species of the Pleuronectiformes and 47 recent species that

have also been described from fossil otoliths are being revised. For this revision I have investigated otoliths of the

majority of the nominal fossil species, mostly including type-material. The results of other important revisions

recently made have been incorporated. As a result of this revision, 26 species are removed from the Pleuro-

nectiformes, 60 fossil species and 35 recent species recorded as fossils are regarded as valid. 18 species are de-

scribed as new: genus aff. Rhombocitharus novaezeelandiae, genus aff. Brachypleura xenosulcis, Pseudorhombus weinfurteri,

Cyclopsetta transitus, Syacium dominicensis, Etropus concaviventris, Grammatobothus awamoaensis, Grammatobothus

radwanskae, Arnoglossus grenfelli, Arnoglossus quadratus, Caulopsetta arnoglossoides, Laeops rharbensis, Samaris validus,

Microchirus wienrichi, Quenselia cornuta, Pseudopardachirolithus nolfi, Peltorhamphus flexodorsalis, Cynoglossus

obliqueventralis. 3 new fossil genera are established, all in the family Soleidae: Granulithus, Praeachirolithus and

Pseudopardachirolithus. The phylogenetic interpretations and conclusions from the character-analysis of the otolith-

morphology are being discussed and compared to published ichthyological analyses. As a result of this several

systematical reallocations within the Pleuronectiformes are being proposed. This includes:

1. The separation of the genera Tephrinectes, Paralichthodes and of the Ammotretis Group from their traditional

allocations to a position near the Citharidae (as early pleuronectiform off springs).

2. Upgrading of the Brachypleuridae to a separate family next to the Citharidae.

3. Reallocation of the genus Azygopus from the Rhombosoleinae (sensu NORMAN, 1934) to the Samarinae.

4. Reallocation of the genus Peltorhamphus from the Pleuronectidae (Rhombosoleinae; sensu NORMAN 1934) to

the Soleidae.

5. Reduction of the Rhombosoleinae (sensu NORMAN, 1934) to include only the two genera Pelotretis and

Rhombosolea.

Dr. Werner SCHWARZHANS, Ahrensburger Weg 103, D-22359 Hamburg, Deutschland.

E-mail: WWSchwarz@aol.com

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Schwarzhans: Pleuronectiformes

Possible relationships are being discussed between the various genera in the Bothidae, Pleuronectidae and Soleidae

as well as between the two families Soleidae and Cynoglossidae. The descriptions and figures of the pleuronectiform

otoliths are arranged in 40 informal “genus groups”, distributed through 8 families and one group of genera of

uncertain relationship, reflecting the results of the otolith analyses. This arrangement is not meant to represent a

new formal subclassification of the order Pleuronectiformes.

With this second volume (as with the previous one) in the newly established Otolithi Piscium Catalogus for-

mat, I have put great emphasis on large and, I hope, clear and detailed drawings. Whenever possible, I tried to

figure more than just one specimen of each species to document intraspecific variability, morphological asymme-

try when and where it occurs and ontogenetic changes in morphology. Due to the nature of the flatfishes, special

emphasis is paid to side dimorphism of their otoliths, which is reflected in depicting otoliths of both sides of the

fishes as far as this was achievable.

With this monograph I hope to fulfill the following main objective: Present as many as possible detailed fig-

ures of recent and fossil pleuronectiform otoliths and thereby create a comprehensive basis for identification and

correlation of otoliths for this order.

Kurzfassung

Im Rahmen einer langfristig angelegten systematischen Bearbeitung vorwiegend rezenter Otolithen befaßt sich

diese Studie mit denjenigen der Ordnung Pleuronectiformes (Plattfische). Im Vergleich zu anderen Teleosteer-

Gruppen gehören die Otolithen der Pleuronectiformes zu den weniger gut bekannten und waren auch bisher nie

Gegenstand einer umfassenden morphologischen Analyse gewesen. Bedingt durch den oft hohen Grad

intraspezifischer Variabilität bei ebenso oft geringen morphologischen Unterschieden zwischen verwandten Ar-

ten und die für Plattfische typische Asymmetrie, die auch bei Otolithen zu beobachten ist, gehört die taxonomische

Arbeit mit Otolithen der Pleuronectiformes zu den komplizierteren innerhalb der Teleosteer.

Für diese Arbeit lagen Otolithen von mehr als 300 rezenten Arten (mehr als 50 % der Pleuronectiformes) zur

Untersuchung vor und zwar Vertreter von 116 der gegenwärtig 133 als valide angesehenen Gattungen. Die 124

beschriebenen fossilen Otolithen-Arten der Pleuronectiformes und 47 rezente Arten, die auch paläontologisch

nachgewiesen wurden, wurden überwiegend auf der Basis eingesehenen Typ-Materials unter Hinzuziehung neuerer

Bearbeitungen revidiert. Die Revision erbrachte , daß 26 Arten keine Pleuronectiformes sind. Von den verbleiben-

den werden 60 fossile Arten und 35 fossile Nachweise rezenter Arten als valide angesehen. Darin enthalten sind 18

neue Arten: genus aff. Rhombocitharus novaezeelandiae, genus aff. Brachypleura xenosulcis, Pseudorhombus weinfurteri,

Cyclopsetta transitus, Syacium dominicensis, Etropus concaviventris, Grammatobothus awamoaensis, Grammatobothus

radwanskae, Arnoglossus grenfelli, Arnoglossus quadratus, Caulopsetta arnoglossoides, Laeops rharbensis, Samaris validus,

Microchirus wienrichi, Quenselia cornuta, Pseudopardachirolithus nolfi, Peltorhamphus flexodorsalis, Cynoglossus

obliqueventralis. Es werden drei neue fossile Gattungen basierend auf Otolithen in der Familie Soleidae aufgestellt:

Granulithus, Praeachirolithus und Pseudopardachirolithus. Die sich aus der morphologischen Charakter-Analyse der

Otolithen ergebenden phylogenetischen Interpretationen werden mit entsprechenden ichthyologischen Analysen

verglichen. Als Ergebnis davon werden einzelne systematische Umstellungen zur Diskussion vorgeschlagen, wie:

1. Abtrennung der Gattungen Tephrinectes, Paralichthodes und der Ammotretis Gruppe in eigene, früh

phylogenetisch auf dem Niveau der Cithariden abgespaltene Gruppen.

2. Aufwertung der Brachypleuridae als familie neben den Citharidae.

3. Umstellung der Gattung Azygopus von der Unterfamilie Rhombosoleinae (sensu NORMAN, 1934) zur Unter-

familie Samarinae.

4. Umstellung der Gattung Peltorhamphus von den Pleuronectidae (Unterfamilie Rhombosoleinae; sensu

NORMAN, 1934) zur Familie Soleidae.

5. Reduzierung der Rhombosoleinae (sensu NORMAN, 1934) auf die beiden Gattungen Pelotretis und Rhombosolea.

Des weiteren werden auf Otolithen-Analyse basierende mögliche generische Verwandtschaften in den Familien

Bothidae, Pleuronectidae und Soleidae sowie mögliche phylogenetische Verbindungen zwischen den Familien

Soleidae und Cynoglossidae ausführlich diskutiert. Die systematische Gliederung der Otolithen-Beschreibungen

und Abbildungen folgt einer informellen, nomenklatorisch unverbindlichen Gliederung in 40 “Gattungs-Grup-

pen” aufgeteilt auf 8 Familien und eine Einheit von Gattungen problematischer Zuordnung.

In diesem zweiten Band der Otolithi Piscium Catalogus Reihe habe ich, ähnlich wie im ersten Band, Wert auf

große und, wie ich hoffe, klare und detaillierte Zeichnungen gelegt. Wenn immer möglich werden mehrere Exem-

plare einer Art gezeigt, um intraspezifische Variabilität, ontogenetische Veränderungen und Seitendimorphismus

zu verdeutlichen. Seitendimorphismus, auch bei Otolithen, ist eine “Spezialität” der Plattfische und dem wird,

soweit möglich, mit der Abbildung von Otolithen beider Seiten des Fisches Rechnung getragen.

Mit dieser Monographie hoffe ich eine Bestimmungs- und Bearbeitungsgrundlage für die Otolithen der

Pleuronectiformes geschaffen zu haben.

Table of contents

1. Introduction and Acknowledgements ............................................................................................................ 5

2. Catalogue of investigated material ................................................................................................................. 9

3. Distribution of recent Pleuronectiformes ....................................................................................................... 10

4. Fossil Pleuronectiformes otoliths..................................................................................................................... 12

4.1 Systematics of fossil Pleuronectiformes otoliths ................................................................................ 12

4.2 Revision of fossil Pleuronectiformes otoliths...................................................................................... 14

4.3 Distribution of fossil Pleuronectiformes faunas ................................................................................. 22

4.3.1 North and Middle America...................................................................................................... 22

4.3.2 Europe .......................................................................................................................................... 22

4.3.3 NW-Africa ................................................................................................................................... 26

4.3.4 Indo-Pacific.................................................................................................................................. 26

4.3.5 New Zealand .............................................................................................................................. 27

5. Phylogenetic usage of Pleuronectiformes otoliths........................................................................................ 27

5.1 Characterization of Pleuronectiformes otoliths .................................................................................. 27

5.2 The origin of the Pleuronectiformes and their outgroup relationship ........................................... 27

5.3 Pleuronectiform ”grouping” according to their otolith morphology.............................................. 28

5.3.1 Evolutionary trends in pleuronectiform otolith morphologies .......................................... 28

5.3.2 Definition of suborders, families and genus groups according to otolith morphologies 29

5.4 Discussion of phylogenetic concepts in Pleuronectiformes ............................................................. 36

6. Morphological characterization of Pleuronectiformes otoliths ..................................................................41

6.1 Terminology.............................................................................................................................................. 41

6.2 Side dimorphism ..................................................................................................................................... 45

6.3 Variability and ontogenetic trends........................................................................................................ 51

6.4 Otoliths of reversed individuals ........................................................................................................... 53

6.5 Sexual dimorphism ................................................................................................................................. 55

7. Descriptive part .............................................................................................................

..................................... 57

7.1 Psettodidae: Psettodes .............................................................................................................................. 57

7.2 Genera of uncertain relationship .......................................................................................................... 62

7.2.1 Tephrinectes Group: Tephrinectes ................................................................................................ 62

7.2.2 Paralichthodes Group: Paralichthodes......................................................................................... 63

7.2.3 Ammotretis Group: Collistium, Ammotretis, Oncopterus, [Psammodiscus], [Taratretis]........ 65

7.3 Citharidae: Citharus, Paracitharus, Citharoides, †Rhombocitharus ....................................................... 70

7.4 Brachypleuridae: Lepidoblepharon, Brachypleura .................................................................................. 84

7.5 Scophthalmidae........................................................................................................................................ 89

7.5.1 Scophthalmus Group: Scophthalmus .......................................................................................... 90

7.5.2 Lepidorhombus Group: Lepidorhombus ...................................................................................... 92

7.5.3 Zeugopterus Group: Zeugopterus, Phrynorhombus................................................................... 100

7.6 Bothidae .................................................................................................................................................... 104

Paralichthyinae

7.6.1 Paralichthys Group: Ancylopsetta, Gastropsetta, Hippoglossina, Xystreurys, Lioglossina,

Paralichthys................................................................................................................................... 106

7.6.2 Pseudorhombus Group: Pseudorhombus, Tarphops, [Cephalopsetta] ........................................ 124

7.6.3 Syacium Group: Syacium, Cyclopsetta....................................................................................... 135

7.6.4 Citharichthys Group: Citharichthys, Orthopsetta, Etropus ....................................................... 145

Bothinae

7.6.5 Bothus Group: Bothus, Parabothus, Grammatobothus .............................................................. 157

7.6.6 Arnoglossus Group: Neolaeops, Arnoglossus, Caulopsetta, Lophonectes, Psettina, Taenio-

psetta ............................................................................................................................................. 165

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Footnote: Genera listed in brackets are not represented by otoliths.

7.6.7 Monolene-Laeops Group: Trichopsetta, Engyophrys, [Perissias], Laeops, [Japanolaeops],

Monolene ....................................................................................................................................... 189

7.6.8 Engyprosopon Group: Asterorhombus, Engyprosopon, Crossorhombus, [Tosarhombus] ......... 199

7.6.9 Thysanopsetta Group: Thysanopsetta ......................................................................................... 205

7.6.10 Chascanopsetta Group: Chascanopsetta, [Pelecanichthys], [Kamoharaia] ................................. 206

7.6.11 Mancopsetta Group: Mancopsetta, [Achiropsetta] ..................................................................... 208

7.7 Pleuronectidae.......................................................................................................................................... 210

Pleuronectinae

7.7.1 Hippoglossus Group: Eopsetta, Hippoglossus ............................................................................ 212

7.7.2 Hippoglossoides Group: Atherestes, Cleisthenes, Lyopsetta, Acanthopsetta, Hippoglossoides,

Reinhardtius.................................................................................................................................. 214

7.7.3 Glyptocephalus Group: Glyptocephalus, Tanakius ..................................................................... 223

7.7.4 Pleuronectes-Limanda Group: Limanda, Dexistes, Liopsetta, Parophrys, Pleuronectes, Platichthys,

Kareius, Pseudopleuronectes, Lepidopsetta, Inopsetta ................................................................. 226

7.7.5 Isopsetta Group: Psettichthys, Isopsetta ..................................................................................... 241

7.7.6 Verasper Group: Verasper, Clidoderma ....................................................................................... 243

7.7.7 Microstomus-Pleuronichthys Group: Microstomus, [Embassichthys], Pleuronichthys, Hypso-

psetta ............................................................................................................................................. 245

Rhombosoleinae

7.7.8 Pelotretis Group: Pelotretis ......................................................................................................... 250

7.7.9 Rhombosolea Group: Rhombosolea .............................................................................................. 252

Samarinae

7.7.10 Samaris Group: Plagiopsetta, Samaris, Samariscus, Azygopus ................................................ 254

Poecilopsettinae

7.7.11 Marleyella Group: Marleyella ..................................................................................................... 264

7.7.12 Poecilopsetta Group: Poecilopsetta, Nematops............................................................................ 265

7.8 Soleidae ..................................................................................................................................................... 269

Achirinae

7.8.1 Achirus Group: Trinectes, Achirus, Catathyridium, Hypoclinemus, Gymnachirus, Nodo-

gymnus.......................................................................................................................................... 270

7.8.2 Apionichthys Group: Apionichthys, [Achiropsis], [Pnictes], [Soleonasus] ............................... 279

Soleinae

7.8.3 Solea Group: Microchirus, Monochirus, Quenselia, Dicologlossa, Solea, [Dageichthys], Microbu-

glossus, Vanstraelenia, Bathysolea ............................................................................................... 280

7.8.4 Synaptura Group: Austroglossus, Synaptura ............................................................................ 306

7.8.5 Brachirus Group: Heterobuglossus, Dexillichthys, Brachirus, Anisochirus, Phyllichthys ....... 310

7.8.6 Zebrias Group: Aesopia, †Granultihus, Soleichthys, Pseudaesopia, Zebrias, [Typhlachirus]... 316

Pardachirinae

7.8.7 Pardachirus Group: †Praeachirolithus, Aseraggodes, †Pseudopardachirolithus, Pardachirus,

[Parachirus]................................................................................................................................... 323

7.8.8. Heteromycteris Group: Heteromycteris, Rendahlia, Peltorhamphus ......................................... 330

7.9 Cynoglossidae .......................................................................................................................................... 338

7.9.1 Cynoglossus Group: Cynoglossus ...............................................................................................

339

7.9.2 Symphurus Group: Symphurus .................................................................................................. 359

8. Selected Literature.............................................................................................................................................. 368

Index ....................................................................................................................................................... 373

Schwarzhans: Pleuronectiformes

Footnote: Genera listed in brackets are not represented by otoliths.

1. Introduction and Acknowledgements

The fishes of the order Pleuronectiformes, or flat-

fishes as they are commonly known, are readily

recognized by their high degree of external asym-

metry. This asymmetry has developed as a re-

sponse to their benthic life-style. Unlike other flat

bodied bottom-living fishes, which have become

laterally expanded and vertically compressed,

such as rays or certain monkfishes, Pleuronecti-

formes are derived from some kind of presuma-

bly deep bodied vertically oriented fish, which

sort of “laid down sideways on the ground”. As

a result of this habit adult Pleuronectiformes

developed a set of unique asymmetrical features

both externally and internally, involving the soft

organs as well as the skeleton and, of course, the

otoliths (larvae are bilaterally symmetrical). For

instance the eye on the side facing ground moves

over the top of the head to a position close to the

eye on the other side. This results in a “blind”

side and an “eyed” side. The skull, mouth, and

the anterior vertebrae, all look “distorted”. The

fins, lateral line system, coloration, even the den-

tition of the mouth and many other characters

are often distinctly asymmetrical. In combination

the resulting asymmetry is so eye-catching and

so different from any other fish that the Pleu-

ronectiformes (or Heterosomata, which better

refers to their appearance) have almost always

been understood as a well defined “natural” sys-

tematic unit.

The asymmetrical specialization of Pleuronec-

tiformes appears to have been a very successful

adaption. Nowadays, flatfishes occur in practi-

cally every ocean and are represented by a large

number of species (more than 550) and genera

(about 132, plus 4 fossil otolith based genera)

distributed amongst 6 to 11 families or more de-

pending on the view of individual taxonomists.

Many flatfishes are of considerable commercial

importance. Such names as turbot (Steinbutt;

Scophthalmus maximus), plaice (plie, Scholle; Pleu-

ronectes platessa) or sole (Seezunge; Solea solea) are

well known from European fish markets and so

are their equivalents from fish markets through-

out the world. Through the systematic works of

NORMAN (1934), CHABANAUD (div.) and

many other authors our status of knowledge of

pleuronectiform fishes is very good.

However, amongst teleost groups of compa-

rable size, the otoliths of the order Pleuronecti-

formes are amongst the least well known. The

work by CHAINE (1936), notable for its superb

photographic technique, stands alone. Unfortu-

nately, some of the illustrations are too small to

be of practical use. The reasons for this discrep-

ancy are, I believe, twofold. Firstly, ichthyologists

working with recent material appear to have been

content with the amount of information gathered

from the complete fish and have paid little care

to what the analysis of otoliths might reveal. Sec-

ondly, paleoichthyologists, who in the past have

been the driving force for investigations of oto-

lith morphology, in both fossil and living fishes,

have been more interested in other Teleost groups

which seemed to promise higher rewards. Indeed,

pleuronectiform otoliths are not the easiest to

work with morphologically. Taxonomic work is

somewhat hampered by the often high degree of

intraspecific variability, the low level of interspe-

cific morphological differentiation and of course

the ubiquitous effects of asymmetry. However,

morphological differentiation is possible in most

cases and in some it may contribute to a better

understanding of pleuronectiform systematics, as

I hope this monograph is able to demonstrate.

My ambition to prepare a comparative morpho-

logical study of pleuronectiform otoliths and to

make it as comprehensive as possible was trig-

gered by the very extensive collection of recent

flatfishes in the collection of The Natural History

Museum, formerly British Museums (Nat. Hist.),

in London. The major portion of the flatfish col-

lection was put together by J. R. NORMAN when

he prepared his “Systematic monograph of the

flatfishes (Heterosomata) – Vol. 1: Psettodidae,

Bothidae, Pleuronectidae” (1934). (The second

part that was proposed to cover the Soleidae and

Cynoglossidae was unfortunately never complet-

ed due to the early death of NORMAN.) This

collection offered a unique opportunity to accu-

mulate a large amount of pleuronectiform otolith

data from a single location and in short time, and

also had the advantage that the fishes had been

identified by one of the most distinguished flat-

fish taxonomists.

In this treatise I tried to compile and figure as

much data as possible for both recent and fossil

pleuronectiform otoliths. Recent otoliths figured

represent 116 genera of the 132 currently recog-

Piscium Catalogus, Part Otolithi piscium, Vol. 2

nized and more than 300 species corresponding

to more than 50 % of the known recent species.

Largest gaps of otolith knowledge are within the

specious genera Bothus, Laeops and Engyprosopon

(Bothidae), Samariscus (Pleuronectidae), Trinectes,

Achirus, Brachirus and Aseraggodes (Soleidae) and

Symphurus (Cynoglossidae). I have concentrated

my efforts on the Pleuronectoidei and therefore

otoliths of the Soleidae and Cynoglossidae are

somewhat less well represented (particularly the

freshwater soleids of America). However, many

of the missing genera (and species, too) are very

rare fishes which are kept in various collections

at different locations. I felt that extending the

study to these taxa would entail very much time

and effort but provide relatively little additional

information. The extent of the data collected for

this study represents a considerable advance on

previously published information and was con-

sidered sufficiently comprehensive to prepare the

following treatise.

As with the previous (and first) volume in the

newly established Otolithi Piscium Catalogus

format – “A comparative morphological treatise

of recent and fossil otoliths of the family Sciaeni-

dae” (SCHWARZHANS 1993) – I have put great

emphasis on large and, I hope, clear and detailed

drawings. Whenever possible, I tried to figure

more than just one specimen of each species to

document intraspecific variability, morphologi-

cal asymmetry when and where it occurs and

ontogenetic changes in morphology.

The compilation of all these recent data would

have been impossible without the most generous

help and support which I received from the fol-

lowing co-scientists and institutions. First and

foremost I wish to cordially thank the authorities

of The Natural History Museum (BMNH, Lon-

don) and in particular Mrs. N. Merrett and O.

Crimmen. Another major source of recent mate-

rial have been otoliths donated by the late J. Fitch,

mostly from the Pacific coast of North and Mid-

dle America. Further I wish to cordially thank:

Mrs. Dose, Mrs. C. Karrer, A. Post and H. Wilkens

(Zoologisches Museum Hamburg – ZMH; and

Institut für Seefischerei, Hamburg – ISH now

transferred to ZMH), J. Nielsen (Universitetets

Zoologiske Museum, Kobenhavn – ZMUC), D.

Nolf (Institut Royale des Sciences Naturelles de

Belgique, Bruxelles – IRSNB), F. Krupp (Sencken-

berg Museum, Frankfurt/M. – SMF), W. Schmidt

(Vockenhausen, Germany), K. Sasaki (Kochi Uni-

versity, Kochi), F. Ohe (Nagakute Senior High

School, Aichi), H. Grenfell (University of Auck-

land), G. Allen (West Australian Museum, Perth –

WAM), R. Mckay (Queensland Museum, Bris-

bane – QMB), P. Castle (National Museum of New

Zealand, Wellington – NMNZ), T. Hecht (Rhodes

University, Grahamstown) and J. Paxton (Aus-

tralian Museum, Sydney – AMS).

The majority of the described fossil pleuronec-

tiform otolith species are revised. As far as pos-

sible these revisions are based on a review of the

type-material or newly collected material prefer-

ably from the type-localities. Wherever appro-

priate, type specimens are being refigured. All

these valuable data were made available most

generously by: F. Stojaspal (Geologische Bunde-

sanstalt, Wien – GBW), D. Nolf (Institute Royale

des Sciences Naturelles de Belgique, Bruxelles –

IRSNB), H. Malz (Senckenberg Museum, Frank-

furt/M. – SMF P), E. Martini (Universität Frank-

furt), W.-D. Heinrich (Paläontologisches Museum

der Humboldt-Universität zu Berlin – PMHUB),

R. Niederl (Steiermärkisches Landesmuseum

Joanneum, Graz – LMJ), Mrs. A. Mastandrea (Uni-

versita di Modena – IPUM), C.H. v.Daniels (Nied-

ersächsisches Landesamt, Hannover – NLH) and

from the private collections of F. Pfeil (München),

Mrs.U. Radwanska (Warszaw – IGUW), E. Rich-

ardson (Henderson, New Zealand), J. Boscheinen

(Düsseldorf), C. Klinger (Düsseldorf), F. von der

Hocht (Kerpen), W. Wienrich (Weetze, Nieder-

rhein), M. Möller (Kleve) and W. Neumann

(Krefeld).

The material kindly made available through

these co-scientists and institutions allowed for

the first time an almost complete revision of the

largest fossil pleuronectiform fauna known to

date: that from Central and Western Europe. Other

important fossil flatfish faunas reviewed include

those described from Central America and New

Zealand. Unfortunately, fossil pleuronectiform

otoliths described from Kazakhstan, Japan and

Indonesia have not been available for revision.

Fossil pleuronectiform otoliths are fairly well

known from Central and Western Europe and

from New Zealand, but from other regions in the

world our knowledge is still very limited. In fu-

ture years I would expect many new fossil flat-

fish otoliths to surface from such areas and I hope

that this monograph will contribute to a better

understanding of them. The rich recent flatfish

faunas in Central America, Japan or Indonesia

already indicate the vast potential range of fossil

forms to be expected from such areas. However,

Schwarzhans: Pleuronectiformes

Recent and fossil pleuronectiform otoliths have

been investigated from the following institution-

al collections:

AIM Auckland Institute and Museum

AMS Australian Museum, Sydney

AUG Auckland University, Geology Depart-

ment

BMNH Natural History Museum), London

BSP Bayer. Staatssammlung für Paläon-

tologie und hist. Geologie, München

GBW Geologische Bundesanstalt, Wien

GPIM-M Paläontologische Institut der Univer-

sität Mainz

IPUM Instituto di Paleontolgia, Universita di

Modena

IRSNB Institut Royale des Sciences Naturelles

de Belgique, Bruxelles

ISH Institut für Seefischerei, Hamburg

(now ZMH)

LMJ Steiermärkisches Landesmuseum

Joanneum, Graz

NLH Niedersächsisches Landesamt, Hanno-

ver

NMB Naturhistorisches Museum, Basel

NMNZ National Museum of New Zealand,

Wellington

NZGS New Zealand Geological Survey,

Lower Hutt

PMHUB Paläontologisches Museum der Hum-

boldt-Universität, Berlin

QMB Queensland Museum, Brisbane

SIO Scripps Institution of Oceanography,

La Jolla

SMF Senckenberg Museum, Frankfurt/M.

USNM National Museum of Natural History,

Washington D.C.

WAM West Australian Museum, Perth

ZMH Zoologisches Museum der Universität

Hamburg

ZMUC Universitetets Zoologiske Museum,

Kobenhavn

ZPalUW Institute of Geology of the University

of Warsaw

and the following private collections:

J. Boscheinen – Düsseldorf (type-material at SMF)

J. Fitch (material donated to the author – Fitch’s

main collection is now at LACM)

H. Grenfell – Auckland (material at AIM and

AUG)

T. Hecht – Grahamstown (material donated and

loaned to the author)

F. von der Hocht – Kerpen (type-material now at

GPIM-M)

C. Klinger – Düsseldorf (type-material at SMF)

E. Martini – Frankfurt/M. (material at University

of Frankfurt)

P. Maxwell – Waimate (type-material now at

NZGS)

M. Möller – Kleve (type-material now at SMF)

W. Neumann – Krefeld (type-material at SMF)

D. Nolf – Brugge (material now at IRSNB)

F. Ohe – Aichi (private collection kept at Naga-

kute Senior High School)

F. Pfeil – München (material now catalogued at

BSP)

U. Radwanska – Warszaw (material now at

ZPalUW)

E. Richardson – Henderson (type-material now

at NZGS)

K. Sasaki – Kochi (material donated to the au-

thor)

W. Schmidt – Vockenhausen near Stuttgart (ma-

terial donated to the author)

W. Schwarzhans – Mülheim a.d. Ruhr (recent

material now catalogued at ISH/ZMH; fossil

type-material now at NZGS, SMF and GBW)

E. Steurbaut – Bruxelles (material now at IRSNB)

W. Wienrich – Weetze (type-material now at SMF)

Recent otoliths are usually stored separately from

the fishes from which they were obtained. It is

from newly collected material by F. Pfeil, W.

Wienrich and myself some new fossil species are

being described. They have been obtained from

locations in Northern Germany, Austria, New

Zealand and Morocco, the latter representing the

first fossil pleuronectiform otoliths from Africa.

I wish to thank Mr. O. Crimmen (London) for

reviewing major parts of the manuscript for Eng-

lish language.

2. Catalogue of Investigated material

Piscium Catalogus, Part Otolithi piscium, Vol. 2

therefore important to give a track record of each

recent otolith specimen as complete as possible.

Unfortunately, this data is not always available.

In recent times the necessity providing good spec-

imen data has become more and more apparent

to otolith workers. (My own collection techniques

have changed in this respect.)

In most institutional collections dissected oto-

liths are kept under the same catalogue number

as the fish. In fossil collections of course cata-

logue numbers refer only to the otoliths. In addi-

tion, in private collections and also in some insti-

tutional collections, there exists a large amount

of non-catalogued material.

In citations of material examined for this trea-

tise the collection number (followed by the cata-

logue number when available) is always noted

first and without brackets or quotation marks.

Additional information may follow in brackets,

for instance:

Collection and catalogue number of the fish

from which the otolith was dissected when not

identical with present location of the otolith spec-

imen.

Prefix – leg. – for material that was donated

from private or institutional collections.

Prefix – coll. – for material that is or was orig-

inally kept in a private collection and became sub-

sequently submitted to an institutional collection.

Any type-material investigated or lectotypes

or neotypes newly selected are quoted accord-

ingly.

The recent otoliths of my formerly private collec-

tion are being transmitted to the ISH collection

(now transferred to the ZMH collection), with

the provision of a lifetime loan-agreement for

myself. This material is not yet catalogued, but

will be catalogued in the course of it being pub-

lished. This will greatly increase the accessibility

of the collection. These otoliths will be catalogued

in a new ZMH (formerly ISH) catalogue format

obeying the following the rules:

ZMH Ot. (stands for assigned otolith collec-

tion) day.month.year.current number (corre-

sponds to the time when the otolith was actually

catalogued). This system is similar to that at the

BMNH.

Flatfishes are adapted to a benthic life-style. They

spend most of their time on the bottom resting on

the blind side. Often they bury themselves in the

sediment, with only the eyes and nostrils uncov-

ered. Some flatfishes, however, are regularly

caught pelagically (Hippoglossus, Reinhardtius).

Psettodes and Reinhardtius are known to adopt a

vertical posture, at least occasionally, the latter

genus probably does so as a secondary adaption

to its pelagic way of living.

Flatfishes are widely distributed in the shal-

low seas of the world. They are most common in

near-shore environments and down to the conti-

nental break (10 to 200 m). Some genera and spe-

cies, however, live at greater depths on the con-

tinental rise (for example Lepidorhombus boscii, Ar-

noglossus rueppelli, Chascanopsetta, Mancopsetta,

Hippoglossus, Glyptocephalus, Poecilopsetta, Bathyso-

lea or Symphurus). Some flatfishes are also found

close inshore, in tidal and subtidal environments

and even in estuarine and brackish waters. Truly

freshwater Pleuronectiformes are rare, most of

them representatives of the family Soleidae (Achi-

rus and Apionichthys Groups). Their occurrence is

restricted to tropical rivers and estuaries, particu-

larly in South America, but also in Africa, the In-

do-Malayan archipelago and northern Australia.

Due to their benthic habit flatfishes are often

adapted to certain kinds of substratum. They are

most abundant in clastic environments on soft

muddy or sandy bottoms. Some genera and spe-

cies are specialized on hard pebbly or rocky bot-

toms (for example Phrynorhombus, Zeugopterus).

But apparently there are also some genera which

occur regularly in coral reef environments (for

example Samariscus) or lagoonal facies settings.

Flatfishes are carnivorous, feeding mostly on

other fish, squids and crustaceans. The largest

flatfishes, like the giant Hippoglossus which can

reach 2 m in length or Reinhardtius are active pred-

ators feeding on a variety of prey, but mostly fish,

squids and prawns. Most other flatfishes hide on

or partially submerged in the sediment waiting

for prey to pass within reach. Soleidae and Cyno-

glossidae are adapted to feed on bottom living

invertebrates (worms, bivalves etc.). Soleidae are

3. Distribution of recent Pleuronectiformes

Schwarzhans: Pleuronectiformes

mostly nocturnally active “creeping” over the

sediment in the search of their prey. The Cynoglos-

sidae are adapted primarily to ploughing the sand

in search of prey and to feeding on organisms

living below the surface.

Geographically, Pleuronectiformes are distrib-

uted throughout the world oceans from the Sub-

arctic in the north (about 75°N) to the Subantarc-

tic in the south (about 55°S, just north of the

Antarctic front), with one species (Mancopsetta ma-

culata) having been collected off the coast of

Antarctica. They are most common and specious,

however, in tropical and subtropical seas. NOR-

MAN (1934) produced a diagram (p.49) depict-

ing the latitudinal range of pleuronectiform fam-

ilies and subfamilies. From this it can be seen that

the majority of flatfishes are distributed between

the Tropic of Cancer and the Tropic of Capricorn

(Psettodidae, many Bothidae, Cynoglossidae,

most Soleidae and the pleuronectid subfamilies

Poecilopsettinae and Samarinae). However, there

are also certain families and groups with a dis-

tinctly antitropical distribution pattern. The Ci-

tharidae are known from the temperate to sub-

tropic seas of Europe and West Africa (Citharus),

South Africa (Paracitharus) and Japan (Citharoides).

Scophthalmidae as a family are exclusively known

from the North Atlantic (most species from the

Northeast Atlantic, only one from the Atlantic

coast of North America) and between the Arctic

Circle and the Tropic of Cancer. Likewise the

majority of the Pleuronectidae (subfamily Pleu-

ronectinae in NORMAN 1934) is restricted to the

temperate and subtropic waters of the North

Pacific and the North Atlantic. The Rhombosolei-

nae (Pelotretis, Rhombosolea and Ammotretis Groups

as defined here) are endemic to the Southern

Oceans, chiefly around New Zealand, southern

Australia and with one species off Patagonia

(South America).

It has been argued that the geographical

spread of shallow marine benthic fishes would to

a certain extend depend on the pelagic larval

phase (see discussion in NORMAN 1934; p.30-33).

This would be particularly important for flatfish-

es, which are not very active swimmers and are

mostly rather sedentary during their adult life,

(exceptions are the more active swimmers like

Hippoglossus, Reinhardtius or Glyptocephalus, and

indeed these are much more widely distributed).

The eggs of the great majority of the Pleuronec-

tiformes are buoyant and pelagic as are their lar-

val stages. Accepting the pelagic life of eggs and

larvae as the principal phase during which geo-

graphical spreading of flatfishes may occur, it

becomes obvious that two factors largely control

their distribution patterns – 1. nature and orien-

tation of oceanic surface currents both in the

Recent and the geological history, and 2. the length

of the pelagic larval life. As for the latter NOR-

MAN (1934) noted that in most Pleuronectinae

the pelagic life is very short, whereas that of the

genera Arnoglossus and Bothus is considerably

prolonged. He also assumed a prolonged early

pelagic life for the genera Syacium and Citharich-

thys, both in essence new world genera known

from a single species each from the West African

coast. A similar situation is recorded for the Mio-

cene, from which a true Syacium species (S. syacio-

ides, not related to the recent S. micrurum from

the West African coast) has been described from

Austria.

In general, however, the spreading of pleu-

ronectiform genera or even species across major

deep ocean “barriers” remains the exception rath-

er than the rule. Indeed one notes a relatively

distinct regionalisation in the distribution pattern

of the Pleuronectiformes. Many flatfish genera

seem to be endemic to certain regions and likely

have been so during their evolution. I assume

that most endemic genera of this type represent

true primary endemics. In the Pleuronectoidei the

largest number of endemic genera is known from

the seas around Japan, Northern China and Ko-

rea (11 genera), the Pacific coast of America (par-

ticularly California; 10 genera) and the temper-

ate seas around New Zealand and southern Aus-

tralia (8 genera). 4 genera are endemic to Europe

and Northwest Africa (Citharus, Lepidorhombus,

Phrynorhombus and Zeugopterus), 3 genera each

to the seas of Indonesia and Southeast America,

2 genera each to the Subantarctic and to South

Africa and 1 genus each to Southwest America,

Hawaii and tropical eastern America. The 4 gen-

era endemic to Europe and Northwest Africa seem

to have long reaching and well established fossil

records in the same area since at least Oligocene

times. However, one of the genera thought to be

endemic for South Africa probably also had a

fossil record from Europe (Paracitharus angustus

from the Pliocene), indicating that its present re-

striction to South Africa probably represents a

secondary endemism. (Similar observations have

been made for other present day endemic fishes

of South Africa as well – for instance Afroscion of

the family Sciaenidae (SCHWARZHANS 1993)

Piscium Catalogus, Part Otolithi piscium, Vol. 2

and Bidenichthys of the family Bythitidae

(SCHWARZHANS 1994). The geographically iso-

lated subtropic and temperate seas around South

Africa seem to represent an ideal refugium for

“living fossils” in the marine life.) In the Soleoi-

dei regionalization seems to be developed best in

the Soleidae. For instance the Achirus and Apion-

ichthys Groups are restricted to the Americas,

whereas all other groups are strictly old world

representatives with the highest degree of diver-

sity in the Indopacific (Brachirus, Zebrias, Pardachi-

rus and Heteromycteris Groups). Biogeographic

analysis of the soleid genera is somewhat ham-

pered by the often unclear delimitation of gener-

ic definitions. Therefore, 7 genera are tentatively

accepted as endemic to the central Indopacific

(Philippines, Indonesia and northern Australia,

of which 1 is endemic to Indonesia and 3 to Aus-

tralia), 6 genera are endemic to South America

(several of them freshwater genera), and 4 are

endemic to Europe and North Africa. Endemism

in other bioprovinces is less well developed: 2

genera in West Africa, 1 in South Africa, 1 in Ja-

pan (not counting the problematical Rhinosolea)

and 1 genus in New Zealand (assuming Peltorham-

phus to represent a soleid). As can be seen from

the above listing the majority of pleuronectoid

endemics occur in temperate to subtropic waters,

whereas the majority of soleoid endemics are trop-

ical (several of them in freshwater). However, they

rarely exceed 10 to 20 % of the total pleuronecti-

form fauna. This is even true for those bioprov-

inces with a very high number of endemic gen-

era, such as Japan or California. The only notable

exception is the flatfish-fauna from New Zealand

and southern temperate Australia. There, 8 out of

15 genera are endemic. Of these endemics 5 are

only known from New Zealand. This high de-

gree of presumably primary endemics is evident-

ly caused by the isolation of the two regions ef-

fective for a considerable interval of time in geo-

logical history. Paleontological findings (see

chapter 4.3.5) support this concept.

4.1 Systematics of

fossil Pleuronectiformes otoliths

Pleuronectiform otoliths are not uncommon in

the fossil record, although they rarely occur in

very great numbers. Since flatfishes are mainly

adapted to shallow marine soft bottom environ-

ments it is not surprising that they are also spe-

cious and common in adequate sediments. But

they are also known, both recent and fossil, from

the deeper shelf or the continental rise. Some

genera are adapted to rocky or reef environments.

These are represented extremely rarely in the

fossil record due to the poor fossilization poten-

tial of the aragonitic otoliths in carbonatic rocks

which prevail in such settings. So far no fossil

pleuronectiform otoliths are known from true

freshwater sediments.

In the stratigraphic record pleuronectiform

otoliths are known best from the Oligocene on-

ward. The oldest certain records date back into

Early Eocene times and are generally represent-

ed by rather plesiomorphic groups such as the

genera Psettodes and Rhombocitharus. But it also

comprises a surprisingly “modern” looking both-

id of the genus Arnoglossus. In the Upper Eocene

two Soleidae are added to the list representing

extinct genera (Praearchirolithus and Pseudop-

ardachirolithus) of the Pardachirinae. In the Up-

per Eocene and Lower Oligocene the number of

“modern” pleuronectiform otoliths increases (a

second Arnoglossus species from New Zealand,

two soleid species and Brachypleura). Records from

the Oligocene and the Neogene reflect a wide

spectrum of families. So far the most commonly

recorded families have been the Bothidae (partic-

ularly the Arnoglossus Group), Soleidae (Solea

Group) and the Citharidae. The Cynoglossidae,

Scophthalmidae and even the Brachypleuridae

are known as well, but less commonly. Amazing-

ly, the poorest fossil knowledge refers to the Pleu-

ronectidae. From this family only two fossil spe-

cies have been noted for certain, one from

the Upper Oligocene of northern Germany

(SCHWARZHANS 1994), the other from the Low-

er Pliocene of New Zealand described as new

below. However, some extant species have been

recorded from the Upper Pliocene and Pleistocene

of California (FITCH, div. pub.) and Japan (OHE

1981, 1983).

4. Fossil Pleuronectiformes otoliths

Schwarzhans: Pleuronectiformes

To date (and including this monograph) about

124 fossil pleuronectiform species based on oto-

liths have been described, mostly from Europe

and New Zealand. In addition about 47 recent

species have also been described as fossils from

Pliocene to Pleistocene sediments of Europe,

North America and Japan. About half of the fos-

sil species are here accepted as valid, i.e. 60 fossil

species (including 18 described as new) and 35 of

the recent species recorded as fossils. Of the three

previously established fossil otolith based gen-

era – Citharopsettodes, Eosolea and Rhombocitharus –

only Rhombocitharus is here regarded as valid;

Citharopsettodes is placed in synonymy with Para-

citharus and Eosolea is not a pleuronectiform. In

addition, three new fossil otolith based genera

are described – Granulithus, Praearchirolithus and

Pseudopardachirolithus. [The formal ending “lithus”

has been attached to the names to indicate that

they are otolith-based fossil genera.]

From the inception of otolith research, fossil

pleuronectiform otoliths have been described by

KOKEN, SCHUBERT, BASSOLI and others. Most

of their species are still regarded as valid. How-

ever, their figures and descriptions have often

been inadequate to allow recognition of the del-

icate features that distinguish closely related spe-

cies from each other. Good documentation and

diagnosis is particularly important in this group

due to the high degree of intraspecific variability,

the often relatively low level of interspecific

morphological differentiation and the prevalence

of poorly preserved or juvenile otoliths lacking

diagnostic features in the fossil record. As a re-

sult of this problematic situation secondary refer-

ences in subsequent publications suffer from in-

adequate identifications. In fact the taxonomic

situation can only be described as chaotic in many

instances. Sorting out all the secondary referenc-

es that have occurred will be a very laborious

task. And before such a task can be realized the

type-material of the earlier works needs to be

thoroughly revised. Such a revision, the re-figur-

ing of types wherever appropriate and the de-

scription of a detailed differential diagnosis is one

of the major objectives of my study (see next

chapter) and hopefully it will help towards a

better identification of fossil pleuronectiform oto-

liths in future investigations. The results of other

important revisions recently made by NOLF

(1981; SCHUBERT’s type-material), STEURBAUT

& JONET (1981; JONET’s type-material), NOLF

& STEURBAUT (1983; BASSOLI’s type-material)

and SCHWARZHANS (1994; KOKEN’s type-

material) have been incorporated. In addition

other type-material or new material from type-

locations was reviewed insofar as it was availa-

ble. However, I regret that there remains still a

number of important type specimens that could

not be investigated. This is particularly true for

the otoliths described by POBEDINA (1954) and

SUZIN (1968) from the Miocene of Kazakhstan,

which are mostly based on juvenile otoliths for

the greater part and are therefore presently re-

garded as of doubtful identity. This also applies

to the otoliths described by FROST (1925), VORST-

MANN (1927) and HATAI (1965) from the Terti-

ary of Indonesia and Japan. Secondary references

have only been taken into consideration when

the specimens have been reviewed or they are

sufficiently identifiable from the illustrations of

the respective publications.

In early publications the diagnostic features

of pleuronectiform otoliths, namely the circum-

sulcal depression (see chapters 5.1. and 6.1. for

explanation), were not recognized. Therefore, a

number of otoliths have originally been described

as representing pleuronectiforms of some sort

which must in fact now be regarded as belonging

to other Teleosts. This is the case for at least 26

nominal species, an unusually high percentage.

In one case, even a genus – Eosolea DANTE &

FRIZZELL 1965 – based on otoliths, and thought

to be a Soleidae, is not in fact a pleuronectiform.

All the species referred to this nominally valid

genus have been identified as belonging to the

Anguilliform family Heterenchelyidae (NOLF &

MARTINELL 1980). On the other hand, only 2

species have been transferred from a systematic

position outside the Pleuronectiformes into this

order.

As already pointed out the number of doubt-

ful fossil species needing thorough revision is still

as high as 20. I strongly recommend against the

use of these species names although they are

nominally valid until proper revisions have been

carried out. 15 fossil species are regarded as syn-

onyms, 2 are rejected as having been based on

indeterminable material and 1 represents a no-

men nudum.

In more recent literature from the 70s onward

the taxonomic problems prevailing in earlier

publications and the difficulties involved in dis-

tinguishing otoliths of related flatfish species

became widely recognized by otolith research

workers and led to a drastic change in their atti-

Piscium Catalogus, Part Otolithi piscium, Vol. 2

tude when describing fossil pleuronectiform oto-

liths. Quite often we now find pleuronectiform

otoliths placed in open nomenclature (NOLF,

RADWANSKA, SCHWARZHANS, STEUR-

BAUT). Fortunately, this attitude has stopped the

introduction of an ever increasing amount of ill-

defined new fossil taxa. Now that the majority of

the type-material is being revised and a previ-

ously unpreceded amount of recent data is avail-

able, new species may be better defined. Howev-

er, it is strongly recommended that in the estab-

lishment of new fossil species certain rules are

observed which should be common sense any-

way: – Making sure that the type-material is of

good quality, is sufficient to demonstrate that the

diagnostic characters do not fall within the vari-

ability range of a previously described species

and represents truly adult specimens that exhibit

enough characters of diagnostic value. Also it is

my suggestion to make significant efforts to pro-

vide illustrations that are as detailed as possible

in order to facilitate future references. This last

point I wish to stress in particular since in the

past many illustrations have been published that

are inadequate for accurate interpretation. Un-

fortunate examples are the publications of FROST,

STINTON and some early works of NOLF. If such

type-material is ever mislaid (and in the case of

FROST some of it evidently has been) it will be

almost impossible, without extensive re-collect-

ing at the type-location (and sometimes not even

then), to “reconstruct” the nature of the respec-

tive species.

Another attitude adopted in more recent stud-

ies and obviously born of the same insight is that

of placing fossil flatfish otoliths, particularly those

from the Younger Tertiary, in living species often

accompanied with some prefix like aff. or cf. This

method is somewhat more problematical. It in-

tends to reflect a status of knowledge which in

fact is not quite the case. Several of these recent

species described as fossils are based on single

and/or poorly preserved specimens that should

better be left in open nomenclature (see chapter

4.2). A clear example of such a misguided attempt

at positive identification is even found in the

publication of such a competent otolith specialist

as OHE (1983), who described several recent

European pleuronectiform species from the

Pliocene of Japan, such as Arnoglossus cf. laterna,

Solea cf. solea or Solea cf. lascaris. Judging from his

photographs most of these are either undetermi-

nable, eroded and/or juvenile specimens or rep-

resent extant Japanese species. In this light I wish

to recommend following the rules outlined above

(for the erection of new fossil taxa) for the alloca-

tion of any fossil otolith to a recent species.

In fact, when reading more recent literature

on fossil otoliths one definitely gets the impres-

sion that fossil pleuronectiform otoliths have not

been a favored group to anybody. For instance

NOLF (1985) noted that the intraspecific variabil-

ity in flatfish otoliths is unusually wide, but: “if

one has a good series of otoliths, the characters of

the species can still be recognized”. SCHWARZ-

HANS (1984) wrote in an introductory chapter to

the Soleoidei that “the morphology is strongly

reduced” and that “here may be one of the few

cases (in Teleosts), where otoliths of related spe-

cies are not always distinguishable”. There is a

lot of truth in both statements. Pleuronectiforms

are indeed among the few Teleost groups where

we have to accept that not all related species may

be distinguishable on the basis of otoliths alone.

Particularly when dealing with fossils one should

treat certain “species” with very generalized

morphologies more like “species groups” than

fully defined species (see entries on Microchirus

frequens and Microchirus kirchbergeanus for in-

stance). However, it is also true that with a large

series of specimens diagnostically valid charac-

ters can still be defined to distinguish such relat-

ed species. This observation not only calls for a

“conservative” approach in taxonomic analyses,

but also means that isolated specimens, particu-

larly when eroded or juvenile, cannot always be

attributed to a certain species.

4.2 Revision of

fossil Pleuronectiformes otoliths

The following is an alphabetical list of fossil pleu-

ronectiform species which are based on otoliths.

Each species name is followed by author and

original designation in brackets and the revised

designation as adopted here. This list includes

every otolith based species originally described

as a pleuronectiform and species that have been

described as belonging to some other Teleost order

but are now accepted as pleuronectiforms. Wher-

ever revisions of other authors are adopted this is

noted.

Species accepted as valid are shown in bold

print.

Schwarzhans: Pleuronectiformes

At the beginning of every new line symbols

show what material has been available for re-

examination. An asterisk (*) denotes re-examined

holotypes or selected lectotypes, # denotes

paratype(s) or syntype(s) (but no holotype) or

any other specimen collected from the type-lo-

cality, a small “s” denotes any other specimens.

In separate lists, doubtful species (based on

inconclusive type material or still needing revi-

sion) and also recent species that have been de-

scribed as fossils are put together. Finally, valid

fossil species and recent species recorded as fos-

sils are listed in their current systematic position.

* acuminatus KOKEN 1891 (Pleuronectidarum) –

Bythitidae

alta STEURBAUT & JONET 1981 (Paraplagu-

sia) – syn. Cynoglossus leuchsi

altus POBEDINA 1954 (Rhombus) – doubtful

species, probably a true pleuronectiform, pos-

sibly a Pleuronectidae, but cannot be evaluat-

ed from figures

* altus MENZEL 1986 (Cynoglossus) – syn. Cy-

noglossus leuchsi

angulata FROST 1925 (Solea) – doubtful spe-

cies, drawing very schematic

s angulosus NOLF 1976 (Lepidorhombus) – Lep-

idorhombus angulosus

s angulosus NOLF 1976 (sensu RADWANSKA

1992) – syn. Lepidorhombus subtriangularis

* angustus SCHWARZHANS 1978 (Citharopset-

todes) – Paracitharus angustus

aomoriensis HATAI 1965 (Limanda) – doubtful

species

s approximata KOKEN 1891 (Solea) – type lost,

can not be evaluated from the illustrations,

species rejected (see entry on Microchirus fre-

quens)

* arnoglossoides n.sp. – Caulopsetta arnoglos-

soides

* awamoaensis n.sp. – Grammatobothus awamo-

aensis

balangoensis VORSTMANN 1927 (Solea) –

doubtful species

s balearicus BAUZA RULLAN 1955 (Eucitha-

rus) – syn. Citharus balearicus

s bartonensis FROST 1934 (Solea) – Heterenche-

lyidae

* bassolii

SCHUBERT 1906 (Phrynorhombus) –

sulcus of unique type eroded, doubtful spe-

cies, not a pleuronectiform

s bauzai SANZ ECHEVERRIA 1950 (Arnoglos-

sus) – syn. Arnoglossus kokeni

* bavayi NOLF 1988 (Psettodes) – genus aff. Pset-

todes bavayi

s belgicus GAEMERS 1972 (Eucitharus) – syn.

Rhombocitharus rhenanus

biaculeatus NOLF & LAPIERRE 1979 (Both-

idarum) – Rhombocitharus biaculeatus

boerialensis VORSTMANN 1927 (Pleuro-

nectes) – Congridae

* cauneillensis NOLF 1988 (Citharus) – Rhom-

bocitharus cauneillensis

s circularis STINTON 1966 (Eucitharus) – Rhom-

bocitharus circularis

claibornensis DANTE & FRIZZELL 1965

(Eosolea) – Heterenchelyidae

* collatus NOLF 1972 (Psettodes) – Psettodes col-

latus

* concaviventris n.sp. – Etropus concaviventris

s concavus PRIEM 1914 (Pleuronectidarum) – Po-

madasyidae

contortus FROST 1934 (Bothus) – doubtful spe-

cies (see NOLF 1985)

corius CHALIKOV 1946 (Rhombus) – doubtful

species, figure in POBEDINA (1954) cannot

be evaluated

* cornuta n.sp. – Quenselia cornuta

corpulentus SUZIN 1968 (Solea) – Callionymi-

dae

cottreaui PRIEM 1911 (Solea) – Myctophidae

(see NOLF 1985)

decipiens

STINTON 1966 (Bothus) – doubtful

species

* dominicensis n.sp. – Syacium dominicensis (as

Bothidae sp. in NOLF & STRINGER, 1992)

* dorsolobatus SCHWARZHANS 1980 (Both-

idarum) – Taeniopsetta dorsolobata

elongatus FROST 1925 (Pleuronectes) – doubt-

ful species, drawing very schematic

* extremus SCHWARZHANS 1980 (Arnoglos-

sus) – Arnoglossus extremus

fangariensis SCHUBERT 1912 (Pleuronecti-

darum) – doubtful species, type lost, cannot

be evaluated from figure

* flexodorsalis n.sp. – Peltorhamphus flexodorsa-

lis

foliformis POBEDINA 1954 (Rhombus) – doubt

ful species (see Nolf 1985)

* fordycei SCHWARZHANS 1980 (Achirus) –

Peltorhamphus fordycei

* frequens STEURBAUT 1984 (Buglossidium) –

Microchirus frequens (replaces “Solea approxi-

mata” of authors)

Piscium Catalogus, Part Otolithi piscium, Vol. 2

glaber KOKEN 1888 (Solea) – Heterenchelyi-

dae

* granum SCHWARZHANS 1994 (Aesopia) –

Granulithus granum

* grenfelli n.sp. – Arnoglossus grenfelli

* guestfalica KOKEN 1891 (Solea) – syn. Rhombo-

citharus rhenanus

heletroides (STINTON ms, in NOLF & CAPET-

TA 1976) (Bothidarum) – nomen nudum, su-

besquently described as Bothidarum biaculea-

tus by NOLF & LAPIERRE 1979

helvecianus JONET 1972 (Pseudorhombus) – He-

terenchelyidae (see STEUTBAUT & JONET

1981)

* holleri WEINFURTER 1952 (Arnoglossus) –

Arnoglossus holleri

hunyadensis SCHUBERT 1912 (Pleuronectida-

rum) – doubtful species, type lost, cannot be

evaluated from figure

* ignobilis SCHWARZHANS 1994 (Limanda) –

Limanda ignobilis

inconspectus SMIGIELSKA 1973 (Arnoglos-

sus) – syn. Arnoglossus taureri

irregularis WEILER 1959 (Pleuronectidarum) –

doubtful species, not identifiable juvenile

pleuronectiform

karaganensis SUZIN 1968 (Rhombus) – Callio-

nymidae

s kirchbergeana H.v.MEYER 1852 (Solea) – Mi-

crochirus kirchbergeanus, found “in situ” by

WEILER 1955

* klockenhoffi GAEMERS & SCHWARZHANS

1982 (Lepidorhombus) – Lepidorhombus klocken-

hoffi

* kokeni

BASSOLI 1906 (Solea) – Arnoglossus

kokeni

* kokeni SCHUBERT 1906 (Solea) – syn. Dico-

loglossa patens

konkensis SUZIN 1968 (Rhombus) – doubtful

species, cannot be evaluated from figure

* lapierrei NOLF 1988 (Bothidarum) – Arnoglos-

sus lapierrei

* latior SCHUBERT 1906 (Solea) – Microchirus

latior

* latisulcatus FROST 1924 (Citharus) – Trachi-

noidei

# lenticularis KOKEN 1884 (Solea) – Nettasto-

matidae

* leuchsi WEINFURTER 1952 (Cynoglossus) –

Cynoglossus leuchsi

lobata BASSOLI 1906 (Platessa) – Chaunacidae

(see NOLF & STEURBAUT 1983)

* longus SCHWARZHANS 1980 (Arnoglossus) –

Arnoglossus longus

# lusitanicus JONET 1972 (Eucitharus) – Citha-

rus lusitanicus

s medius WEILER 1958 (Phrynorhombus) –

Phrynorhombus medius

s minor SCHUBERT 1906 (Rhombus) – Hemi-

rhamphidae

miocenica POBEDINA 1954 (Rhombus) – doubt-

ful species, cannot be evaluated from figure

miocenicus WEILER 1942 (Eucitharus) – Citha-

rus sp., based on non-diagnostic juvenile,

doubtful species.

s miocenicus WEILER 1962 (Arnoglossus)

– syn.

Arnoglossus holleri

* nolfi n.sp. – Pseudopardachirolithus nolfi

* novaezeelandiae n.sp. – genus aff. Rhomboci-

tharus novaezeelandiae

* novus SCHWARZHANS 1980 (Arnoglossus) –

Arnoglossus novus

* obliquoventralis n.sp. – Cynoglossus obliquo-

ventralis

* obliquus MENZEL 1986 (Bothidarum) – syn.

Phrynorhombus medius

* oedelemensis NOLF 1972 (Psettodes) -syn. Pset-

todes collatus

* orbicularis FROST 1933 (Pleuronectidarum) –

rejected fragmentary species

otomoi HATAI 1965 (Limanda) – doubtful spe-

cies

s patens BASSOLI 1906 (Solea) – Dicologlossa

patens

* pentagonalis STEURBAUT 1984 (Pleuronecti-

darum) – Brachypleura pentagonalis

* polonica n.sp.- Bathysolea polonica

premaxima SHEPHERD 1916 (Psetta) – syn. Ge-

nartina hampshirensis, family indeterminable,

probably close to Pterothrissidae (NOLF 1985)

* priscus SCHWARZHANS 1994 (Monolene) –

Monolene priscus

# prudhommae STEURBAUT 1984 (Monolene) –

Arnoglossus prudhommae

* quadratus n.sp. – Arnoglossus quadratus

* radwanskae n.sp. – Grammatobothus radwan-

skae

rharbensis n.sp. – Laeops rharbensis

* rhenanus KOKEN 1891 (Rhombus) – Rhomboc-

itharus rhenanus

* rhenanus KOKEN 1891 (sensu SCHUBERT

Schwarzhans: Pleuronectiformes

1906) – syn. Lepidorhombus subtriangularis

rhenanus KOKEN 1891 (sensu LIEBUS 1927) –

from the Upper Cretaceous of Austria, an un-

described Acropomatidae of the fossil genus

Plesiopoma (SCHWARZHANS 1995)

rhenanus KOKEN 1891 (sensu WEINFURTER

1952) – Citharus lusitanicus

* rhomboides SCHWARZHANS 1973 (Bothi-

darum) – Rhombocitharus rhomboides

roseni NOLF & CAPETTA 1980 (Paraplagusia) –

syn. Cynoglossus leuchsi

s rosenthalensis WEILER 1942 (Bothus) –

Zeugopterus rosenthalensis

s rotunda PRIEM 1914 (Gobius) – Solea rotunda

(STEURBAUT 1984)

rotundus SUZIN 1968 (Solea) – doubtful spe-

cies, not identifiable juvenile pleuronectiform

* schuberti BASSOLI 1906 (Eucitharus) – Citha-

rus schuberti

# schultzei NOLF & LAPIERRE 1979 (Solei-

darum) – Praearchirolithus schultzei

sector KOKEN 1891 (Platessa) – Congridae

sectoroides SCHUBERT 1906 (Pleuronectes) –

Congridae

# semen NOLF 1972 (Bothus) – not a pleuronec-

tiform

simplex POBEDINA 1954 (Solea) – doubtful

species, cannot be evaluated from figure

* solitarius ROEDEL 1928 (Solea) – rejected spe-

cies, not identifiable fragmentary otolith, not

a pleuronectiform

songgoensis VORSTMANN 1927 (Solea) –

doubtful species

* splendens SCHUBERT 1906 (Pleuronecti-

darum) –

Laeops splendens

* spinosus NOLF 1972 (Psettodes) – syn. Psettodes

collatus

s subglaber SCHUBERT 1906 (Solea) – Heter-

enchelyidae

subrostratus SCHUBERT 1908 (Pleuronecti-

darum) – Gonostomiatidae (see NOLF &

STEURBAUT 1981)

s subtriangularis HEINRICH 1970 (Lepidorhom-

bus) – Lepidorhombus subtriangularis

* subvulgaris SCHUBERT 1906 (Solea) – syn.

Microchirus kirchbergeanus

# sulci STEURBAUT 1984 (Solea) – Pseudo-

pardachirolithus sulci

* syacioides WEINFURTER 1952 (Pleuronecti-

darum) – Syacium syacioides

s taureri WEINFURTER 1952 (Solea) – Arnoglos-

sus taureri

temputulensis POSTHUMUS 1929 (Pleuronecti-

darum) – not a pleuronectiform (WEILER

1968)

* tenuis SCHUBERT 1906 (Solea) – based on

unique juvenile specimen, doubtful species,

possibly syn. Laeops splendens

texana DANTE & FRIZZELL 1965 (Eosolea) –

a Heterenchelyidae

* transitus n.sp. – Cyclopsetta transitus (as Pleu-

ronectiformorum sp. in NOLF, 1976)

* validus n.sp. – Samaris validus

varians STINTON 1966 (Citharichthys) – reject-

ed species (NOLF 1985)

* vulsus STINTON 1958

(Pleuronectes) – a frag-

mentary and not identifiable Cepolidae

weileri GAEMERS 1972 (Sebastes) – ? syn.

Rhombocitharus rhenanus

* weileri SCHWARZHANS 1974 (Bothidarum) –

syn. Rhombocitharus rhenanus

* weinfurteri n.sp. – Pseudorhombus weinfurteri

* wienrichi n.sp. – Microchirus wienrichi

* xenosulcis n.sp. – genus aff. Brachypleura xeno-

sulcis (as Bothidae sp. in NOLF & BAJPAI,

1992)

The following is a list of species regarded as

doubtful. It contains species based on inconclu-

sive type-material (juvenile and/or eroded types

whose status has not been clarified by subsequent

findings) or species still needing revision. Type

location and formation is added. These names –

although nominally valid – should not be used in

future descriptions of fossil faunas until revision

is carried out or until additional material has been

obtained to clarify the status.

altus, Rhombus, POBEDINA 1954 from the Upper

Miocene of Kazakhstan

angulata, Solea, FROST 1925 from the Neogene of

Sumatra

aomoriensis, Limanda, HATAI 1965 from the

Pliocene of Japan

balangoensis, Solea, VORSTMANN 1927 from the

Upper Eocene of Java

contortus, Bothus, FROST 1934 from the Upper

Eocene of England

corius, Rhombus, CHALIKOV 1946 (in POBEDI-

NA 1954) from the Upper Miocene of Kaza-

khstan

decipiens, Bothus, STINTON 1966 from the Lower

Eocene of England

Piscium Catalogus, Part Otolithi piscium, Vol. 2

elongatus, Pleuronectes, FROST 1925 from the Neo-

gene of Sumatra

fangariensis, Pleuronectidarum, SCHUBERT 1912

from the Miocene of Sardinia

foliformis, Rhombus, POBEDINA 1954 from the

Upper Miocene of Kazakhstan

hunyadensis, Pleuronectidarum, SCHUBERT 1912

from the Lower Miocene of Hungary

irregularis, Pleuronectidarum, WEILER 1959 from

the Lower Miocene of Mexico

konkensis, Rhombus, SUZIN 1968 from the Lower

Pliocene of Kazakhstan

miocenica, Rhombus, POBEDINA 1954 from the

Upper Miocene of Kazakhstan

miocenicus, Eucitharus, WEILER 1942 from the

Lower Miocene of Germany

otomoi, Limanda, HATAI 1965 from the Pliocene

of Japan

rotundus, Solea, SUZIN 1968 from the Lower

Pliocene of Kazakhstan

simplex, Solea, POBEDINA 1954 from the Upper

Miocene of Kazakhstan

songgoensis, Solea, VORSTMANN 1927 from the

Upper Eocene of Java

tenuis, Solea, SCHUBERT 1906 from the Middle

Miocene of Austria

The following is a compilation of recent species

to which fossil specimens have been assigned.

Wherever appropriate a revised identification is

included. Records regarded as valid are shown

in bold print.

asperrimum, Clidoderma, (as Lyopsetta cf. exilis in

OHE, 1983) -Upper Pliocene of Japan

atricaudus, Symphurus, (in FITCH, 1966) – Pleis-

tocene of California

bilineata, Paraplagusia, (in OHE, 1981) – Pliocene

of Japan

boscii, aff., Lepidorhombus, (in NOLF, 1978) –

Pliocene of Belgium, an inidentifiable eroded

specimen of the genus Lepidorhombus

californicus, Paralichthys, (in FITCH, 1964, 1967a,

1970) – Upper Pliocene and Pleistocene of

California

commersoniana, cf., Synaptura, (in OHE, 1981) –

Pliocene of Japan, not a pleuronectiform

cornutus, Pleuronichthys, (in OHE, 1981) – Pliocene

of Japan

cuneata, Dicologlossa (in STEURBAUT & JONET,

1981) – Lower Miocene of Portugal, Dicologlos-

sa patens

cuneata, aff., Dicologlossa, (in RADWANSKA,

1992) – Middle Miocene of Poland, Microchi-

rus kirchbergeanus (pars) and Pseudorhombus

weinfurteri

exilis,

Lyopsetta, (in FITCH, 1964, 1967a, 1967b,

1968, 1970) – Upper Pliocene and Pleistocene

of California

exilis, cf., Lyopsetta, (in OHE, 1983) – Upper

Pliocene of Japan, Clidoderma asperrimum

ferruginea, aff., Limanda, (in NOLF, 1978) – Pleis-

tocene of Belgium, Limanda limanda

flesus, Platichthys, ( in STINTON, 1985) – Pleis-

tocene of southern England

hexophthalma, aff., Dicologlossa, (in STEURBAUT

& JONET, 1981 and STEURBAUT, 1984) – Mio-

cene of Portugal and SW-France, probably an

undescribed species of Quenselia

imperialis, Arnoglossus, – Lower Pliocene of Bel-

gium

imperialis, aff., Arnoglossus, (in LANCKNEUS &

NOLF, 1979) – Upper Miocene of NW-France,

an indeterminable juvenile otolith of the ge-

nus Arnoglossus

isolepis, Isopsetta, (in FITCH, 1970) – Pleistocene

of California

japonica, Paraplagusia, (in OHE, 1981) – Pliocene

of Japan

jordani, Eopsetta, (in FITCH, 1967b, 1970) – Pleis-

tocene of California

joyneri, cf., Cynoglossus, (in OHE, 1981) – Pliocene

of Japan

lascaris, Pegusa, (in GAEMERS &

SCHWARZHANS, 1973) – Pliocene of Bel-

gium, Microchirus variegatus

lascaris, cf., Solea, (in OHE, 1981) – Pliocene of

Japan, Heteromycteris sp.

laterna, Arnoglossus, (in GAEMERS &

SCHWARZHANS, 1973 and NOLF 1978) –

Pliocene of Belgium

laterna, Arnoglossus, (in ANFOSSI & MOSNA,

1979) – Lower Plicene of Italy, Arnoglossus

kokeni

laterna, cf., Arnoglossus, (in OHE, 1981) – Pliocene

of Japan, Paralichthys aff. olivaceus

laterna, Arnoglossus, (in RADWANSKA, 1992) –

Middle Miocene of Poland, Arnoglossus taureri

limanda, Limanda,

(in GAEMERS, 1974 and NOLF,

1978 as Limanda aff. ferruginea) – Pleistocene

of Belgium, (in STINTON, 1985) Pleistocene

of southern England

linguatula, Citharus, (in NOLF & CAPPETTA

1988) – Lower Pliocene of SW-France, Citha-

rus balearicus

Schwarzhans: Pleuronectiformes

lugubris, cf., Chascanopsetta, (in OHE, 1981, 1983) –

Pliocene of Japan, probably an undescribed

species of Tarphops

luteum, Buglossidium, (in NOLF 1978) – Pliocene

of Belgium, probably Microchirus variegatus

nigrescens, Symphurus, – Lower Pliocene of NW-

Morocco

olivaceus, aff., Paralichthys, (as Arnoglossus cf. lat-

erna in OHE, 1981) – Pliocene of Japan

pacificus, Microstomus, (in FITCH, 1968) – Pleis-

tocene of California

panamensis, aff., Cyclopsetta, (as ?Pleuronectidae

indet. in NOLF & STRINGER, 1992) – Pliocene

of Dominican Republic

pavoninus, cf., Pardachirus, (in OHE, 1981) –

Pliocene of Japan

pentophthalmus, Pseudorhombus, (in OHE, 1981,

1983) – Pliocene of Japan, indeterminable

eroded otoliths, possibly of the family Solei-

dae

platessa, Pleuronectes, (in STINTON, 1985) – Pleis-

tocene of southern England

platessa, cf., Pleuronectes, (in NOLF, 1978) – Pleis-

tocene of Belgium, indeterminable eroded

pleuronectid otolith

platessoides, Hippoglossoides, (in GAEMERS,

1974) – Pleistocene of Belgium

punctatus, cf., Zeugopteru,s (in NOLF, 1978) –

Pliocene of Belgium, cannot be evaluated from

figure

ritteri, Pleuronichthys, (in FITCH, 1964, 1970) –

Pleistocene of California

senegalensis, aff. Solea, (in STEURBAUT, 1979) –

Miocene of SW-France, single eroded speci-

men, likely representing Dicologlossa patens

solea, Solea, (in RADWANSKA, 1992) – Middle

Miocene of Poland, Dicologlossa patens (pars)

and Solea rotunda (pars)

solea, cf., Solea, (in Ohe, 1981) – Pliocene of Japan,

probably a species of the genus Pseudorhom-

bus

sordidus, Citharichthys, (in FITCH, 1964, 1967a, b,

1968, 1970) – Upper Pliocene and Pleistocene

of California

stellatus, Platichthys, (in FITCH, 1970) – Pleisto-

cene of California

stenolepis, Hipoglossus, (in FITCH, 1970) – Pleisto-

cene of California

stigmaeus, Citharichthys, (in FITCH, 1964,

1967a, b, 1968, 1970) – Upper Pliocene and

Pleistocene of California

stomias, Atherestes, (in FITCH, 1968, 1970) – Pleis-

tocene of California

tenius, Peltorhamphus, – Lower Pliocene of New

Zealand

ui, Engyproson, (in OHE, 1981, 1983) – Pliocene of

Japan, eroded specimens, probably indeter-

minable ui, aff., Engyprosopon, (in OHE 1981) –

Pliocene of Japan, probably an undescribed

species of the genus Tarphops

variegatus, Microchirus, (in NOLF, 1978, STIN-

TON, 1985 and GAEMERS & SCHWARZ-

HANS, 1973 as Pegusa lascaris) – Pliocene and

Pleistocene of Belgium and southern England

variegatus, Microchirus, (in NOLF & CAPPETTA

1988) – Pliocene of France, probably an unde-

scribed species of the genus Microchirus

variegatus, aff., Microchirus, (in RADWANSKA,

1992) – Middle Miocene of Poland, Microchi-

rus latior

vetulus, Parophrys, (in FITCH, 1964, 1967a, 1968,

1970) – Pleistocene of California

vulgaris, Solea, (in STINTON, 1985) – Pleistocene

of southern England

whiffiagonis, Lepidorhombus, (in GAEMERS &

SCHWARZHANS, 1973) – Pliocene of Bel-

gium

xanthostigma, Citharichthys, (in FITCH, 1968,

1970) – Pleistocene of California

zachirus, Glyptocephalus, (in FITCH, 1967b, 1968,

1970) – Pleistocene of California

In the following summary-list all fossil records

accepted as valid are compiled in their current

systematic position. The list contains both fossil

otolith based species as well as recent species

which have been recorded as fossils. It also in-

cludes stratigraphic and geographic distributions.

Psettodidae

Psettodes collatus NOLF 1972 – Middle Eocene of

Belgium

genus aff. Psettodes bavayi (NOLF 1988) – Lower

Eocene of France (Aquitaine Basin)

Citharidae

Citharus balearicus BAUZA RULLAN 1955 – Up-

per Pliocene of Mallorca (Spain) and Lower

Pliocene of SW-France and Morocco

Citharus lusitanicus JONET 1972 – Lower to Mid-

dle Miocene of Portugal, France (Aquitaine

Basin), Austria and Poland (both Paratethys)

Citharus schuberti BASSOLI 1906 – Upper Miocene

and Lower Pliocene of Italy

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Paracitharus angustus (SCHWARZHANS 1978) –

Lower Pliocene of Italy

Rhombocitharus biaculeatus (NOLF & LAPIERRE

1979) – Middle Eocene of Belgium and Eng-

land

Rhombocitharus cauneillensis (NOLF 1988) – Up-

per Eocene of France (Aquitaine Basin)

Rhombocitharus circularis (STINTON 1966) – Low-

er Eocene of England and France (Aquitaine

Basin)

Rhombocitharus rhenanus (KOKEN 1891) – Mid-

dle and Upper Oligocene of northern Germa-

ny and Mainz Basin

Rhombocitharus rhomboides (SCHWARZHANS

1973) – Lower Miocene of northern Germany

genus aff. Rhombocitharus novaezeelandiae n.sp. –

Upper Oligocene of New Zealand.

Brachypleuridae

Brachypleura pentagonalis (STEURBAUT 1984) –

Lower Oligocene of France (Aquitaine Basin)

genus aff. Brachypleura xenosulcis n.sp. – Upper

Eocene of Java

Scophthalmidae

Lepidorhombus angulosus NOLF 1976 – Lower and

Middle Miocene of Belgium and northern

Germany

Lepidorhombus klockenhoffi GAEMERS &

SCHWARZHANS 1982 – Upper Miocene of

northern Germany

Lepidorhombus subtriangularis HEINRICH 1970 –

Upper Oligocene to Middle Miocene of north-

ern Germany, Middle Miocene of Austria and

Poland

Lepidorhombus whiffiagonis (WALBAUM 1792) –

Recent species, also known from the Lower

Pliocene of Belgium

Zeugopterus rosenthalensis (WEILER 1942) – Up-

per Oligocene of northern Germany

Zeugopterus cf. punctatus (BLOCH 1787) – Recent

species, also known from the Lower Pliocene

of Belgium

Phrynorhombus medius WEILER 1958 – Lower to

Upper Miocene of northern Germany

Bothidae

Paralichthys californicus (AYRES 1862) – Recent

species, also known from the Upper Pliocene

and Pleistocene of California

Paralichthys aff. olivaceus (TEMMINCK & SCH-

LEGEL 1846) – Recent species, also known

from the Pliocene of Japan

Pseudorhombus weinfurteri n.sp. – Middle Miocene

of Austria

Cyclopsetta aff. panamensis (STEINDACHNER

1875) – Recent species, also known from the

Pliocene of Dominican Republic

Cyclopsetta transitus n.sp. – Lower Miocene of

Trinidad

Syacium dominicensis n.sp. – Upper Miocene of

Domonican Republic

Syacium syacioides (WEINFURTER 1952) – Mid-

dle Miocene of Austria

Citharichthys sordidus (GIRARD 1856) – Recent

species, also known from the Upper Pliocene

and Pleistocene of California

Citharichthys stigmaeus JORDAN & GILBERT

1883 – Recent species, also known from the

Upper Pliocene and Pleistocene of California

Citharichthys xanthostigma GILBERT 1890 – Re-

cent species, also known from the Pleistocene

of California

Etropus concaviventris n.sp. – Upper Miocene of

Dominican Republic

Grammatobothus awamoaensis n.sp. – Lower Mio-

cene of New Zealand

Grammatobothus radwanskae n.sp. – Middle Mio-

cene of Poland

Arnoglossus extremus

SCHWARZHANS 1980 –

Upper Eocene of New Zealand

Arnoglossus grenfelli n.sp. – Lower Pliocene of New

Zealand

Arnoglossus holleri WEINFURTER 1952 – Lower

and Middle Miocene of northern Germany,

Lower and Middle Miocene of Austria, Po-

land, Portugal and SW-France

Arnoglossus imperialis (RAFINESQUE 1810) –

Recent species, also known from the Lower

Pliocene of Belgium

Arnoglossus kokeni (BASSOLI 1906) – Upper Mi-

ocene of Italy, Lower Pliocene of Morocco and

southern France and Pliocene of Spain

Arnoglossus lapierrei NOLF 1988 – Lower Eocene

of France (Aquitaine Basin)

Arnoglossus laterna (WALBAUM 1792) – Recent

species, also known from the Lower and

Upper Pliocene of Belgium

Arnoglossus longus SCHWARZHANS 1980 – Up-

per Oligocene and Lower Miocene of New

Zealand

Arnoglossus novus SCHWARZHANS 1980 – Low-

er and Middle Miocene of New Zealand

Arnoglossus prudhommae (STEURBAUT 1984) –

Lower Oligocene of France (Aquitaine Basin)

Schwarzhans: Pleuronectiformes

Arnoglossus quadratus n.sp. – Lower Pliocene of

NW-Morocco

Arnoglossus taureri (WEINFURTER 1952) – Low-

er and Middle Miocene of Austria, Poland and

Portugal

Caulopsetta arnoglossoides n.sp. – Lower Miocene

of New Zealand

Taeniopsetta dorsolobata (SCHWARZHANS 1980) –

Lower Miocene of New Zealand

Laeops splendens (SCHUBERT 1906) – Middle

Miocene of Austria and Poland

Laeops rharbensis n.sp. – Lower Pliocene of NW-

Morocco

Monolene priscus SCHWARZHANS 1994 – Upper

Oligocene of northern Germany

Pleuronectidae

Eopsetta jordani (LOCKINGTON 1880) – Recent

species, also known from the Pleistocene of

California

Hippoglossus stenolepis SCHMIDT 1904 – Recent

species, also known from the Pleistocene of

California

Atherestes stomias (JORDAN & GILBERT 1881) –

Recent species, also known from the Pleisto-

cene of California

Hippoglossoides platessoides (FABRICIUS 1780) –

Recent species, also known from the Pleisto-

cene of Belgium

Lyopsetta exilis (JORDAN & GILBERT 1881) –

Recent species, also known from the Upper

Pliocene and Pleistocene of California

Glyptocephalus zachirus LOCKINGTON 1878 –

Recent species, also known from the Pleisto-

cene of California

Clidoderma asperrimum (TEMMINCK & SCH-

LEGEL 1846) – Recent species, also known

from the Upper Pliocene of Japan

Limanda ignobilis SCHWARZHANS 1994 – Up-

per Oligocene of northern Germany

Limanda limanda (LINNAEUS 1758) – Recent spe-

cies, also known from the Pleistocene of Bel-

gium and England

Parophrys vetulus GIRARD 1856 – Recent species,

also known from the Pleistocene of California

Pleuronectes platessa LINNAEUS 1758 – Recent

species, also known from the Pleistocene of

England

Platichthys flesus (LINNAEUS 1758) – Recent spe-

cies, also known from the Pleistocene of Eng-

land

Platichthys stellatus (PALLAS 1787) – Recent spe-

cies, also known from the Pleistocene of Cali-

fornia

Microstomus pacificus (LOCKINGTON 1878) –

Recent species, also known from the Pleisto-

cene of California

Pleuronichthys cornutus (TEMMINCK & SCH-

LEGEL 1846) – Recent species, also known

from the Pliocene of Japan

Pleuronichthys ritteri STARKS & MORRIS 1907 –

Recent species, also known from the Pleisto-

cene of California

Isopsetta isolepis (LOCKINGTON 1881) – Recent

species, also known from the Pleistocene of

California

Samaris validus n.sp. – Lower Pliocene of New

Zealand

Soleidae

Microchirus frequens (STEURBAUT 1984) – Upper

Oligocene and Lower Miocene of France

(Aquitaine Basin), Upper Oligocene (?to Up-

per Miocene) of northern Germany, Belgium

and the Netherlands

Microchirus kirchbergeanus (H.v.MEYER 1852) –

known from otoliths and skeletons with oto-

liths “in situ” from the Middle Miocene of

Bavaria, Austria, Poland and the Lower Mio-

cene of Portugal

Microchirus latior (SCHUBERT 1906) – Lower and

Middle Miocene of Austria

Microchirus variegatus (DONOVAN 1802) – Re-

cent species, also known from the Pliocene

and Pleistocene of Belgium and England

Microchirus wienrichi n.sp. – Lower and Middle

Miocene of northern Germany, Belgium and

the Netherlands

Dicologlossa patens (BASSOLI 1906) – Lower to

Upper Miocene of Italy, Austria, France and

Portugal

Quenselia cornuta n.sp. – Lower Pliocene of NW-

Morocco and possibly also Upper Miocene of

Portugal

Solea rotunda (PRIEM 1914) – Lower Miocene of

France (Aquitaine Basin), Middle Miocene of

Poland

Solea vulgaris QUENSEL 1806 – Recent species,

also known from the Pleistocene of England

Bathysolea polonica n.sp. – Middle Miocene of

Poland

Granulithus granum SCHWARZHANS 1994 –

Upper Oligocene of northern Germany

Praearchirolithus schultzei NOLF & LAPIERRE

1979 – Upper Eocene of France (Paris Basin)

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Pardachirus cf. pavoninus (LACEPEDE 1802) –

Recent species, also known from the Pliocene

of Japan

Pseudopardachirolithus nolfi n.sp. – Upper Eocene

of France (Paris Basin)

Pseudopardachirolithus sulci STEURBAUT 1984 –

Upper Oligocene and Lower Miocene of-

France (Aquitaine Basin)

Peltorhamphus flexodorsalis n.sp. – Lower Pliocene

of New Zealand

Peltorhamphus fordycei (SCHWARZHANS 1980) –

Middle Miocene of New Zealand

Peltorhamphus tenuis JAMES 1972 – Recent spe-

cies, also known from the Lower Pliocene of

New Zealand

Cynoglossidae

Cynoglossus (Paraplagusia) bilineata (BLOCH

1785) – Recent species, also known from the

Pliocene of Japan

Cynoglossus (Paraplagusia) japonica (TEMMINCK

& SCHLEGEL 1846) – Recent species, also

known from the Pliocene of Japan

Cynoglossus cf. joyneri GÜNTHER 1878 – Recent

species, also known from the Pliocene of Ja-

pan

Cynoglossus leuchsi WEINFURTER 1952 – Lower

and Middle Miocene of Austria, France (Aqui-

taine and Mediterranean Basins), Portugal and

northern Germany

Cynoglossus obliqueventralis n.sp. – Lower Pliocene

of NW-Morocco

Symphurus atricaudus (JORDAN & GILBERT

1880) – Recent species, also known from the

Pleistocene of California

Symphurus nigrescens RAFINESQUE 1810 – Re-

cent species, also known from the Lower

Pliocene of NW-Morocco

4.3 Distribution of

fossil pleuronectiform faunas

based on otolith findings

4.3.1 North and Middle America

Pliocene and Pleistocene – California.

References: FITCH (div.).

In various publications FITCH has reported a

total of 15 otolith based pleuronectiform species

from the Pliocene and Pleistocene of California.

They all represent living species from that region.

Miocene and Pliocene – Mexico, Trinidad and

Dominican Republic.

References: WEILER 1959, NOLF 1976, NOLF &

STRINGER 1992.

Pleuronectiform otoliths seem to be quite com-

mon and specious in these sediments judging

from the amount of taxa recorded from just a few

localities. WEILER (1959) described a genus Pleu-

ronectidarum irregularis from the Lower Miocene

of Mexico. This species, however, was based on

juvenile otoliths without really diagnostic char-

acters and should be regarded as a doubtful spe-

cies for the time being. NOLF (1976) left four

species, from various Miocene strata of Trinidad,

in open nomenclature, because he felt that not

enough recent pleuronectiform otoliths were

known from the area. This situation has changed

now. One species from the Lower Miocene is here

described as Cyclopsetta transitus (as genus Pleu-

ronectiformorum sp.1 in NOLF 1976). The others

are too poorly preserved for specific identifica-

tion. They represent Citharichthys sp., an uniden-

tifiable bothid and a species of Symphurus. The

material described by NOLF & STRINGER (1992)

from the Upper Miocene and Pliocene of the

Dominican Republic contains five pleuronecti-

forms, which they likewise left in open nomen-

clature. Three of them are described here as Cyclo-

psetta aff. panamensis (as ?Pleuronectidae indet. in

NOLF & STRINGER 1992) from the Pliocene,

Syacium dominicensis (as Bothidae indet.) from the

Upper Miocene and Etropus concaviventris also

from the Upper Miocene. In addition there are

two unidentifiable species, one of the genus Sym-

phurus and a soleid of the genus Achirus (as Solei-

dae indet.) both from the Upper Miocene.

This short list documents the potential for

future discoveries of pleuronectiform otoliths in

the general area. From my colleague A. MÜLLER

I was informed that a number of pleuronectiform

otoliths have also surfaced during his ongoing

research in Neogene strata of the Atlantic coast of

the United States and the Miocene of Ecuador.

4.3.2 Europe

The largest number of fossil pleuronectiform oto-

liths until now has been described from the Eu-

ropean younger Tertiary. This is an artificial situ-

ation reflecting only the high level of investiga-

tion this area has received in the past. Once other

Schwarzhans: Pleuronectiformes

areas have been studied more extensively there

will undoubtedly be a shift of importance to such

areas as Middle America or the Far East (Japan,

China and Indonesia).

The taxonomic status of many of the pleu-

ronectiform otolith records from Europe is badly

in need of revision (as indicated above), in partic-

ular the many secondary references and speci-

mens left in open nomenclature in more recent

literature. I have reviewed a fair proportion of

type- and non-type-material from a considerable

number of locations. However, the taxonomic

summary presented below must still be regarded

as incomplete. This is particularly true as far as

the geographic and stratigraphic distribution of

the various species is concerned.

Eocene – Belgium, Great Britain and France

References: FROST 1934, STINTON 1966, NOLF

1972a,b, NOLF & CAPPETTA 1976, NOLF &

LAPIERRE 1979, NOLF 1988.

Lower to Upper Eocene strata from Belgium,

Great Britain and France have yielded the earli-

est otolith records of the Pleuronectiformes. Most

otoliths represent very plesiomorphic genera.

Psettodidae such as Psettodes collatus from the

Middle Eocene of Belgium and genus aff. Pset-

todes bavayi from the Lower Eocene of the Aqui-

taine Basin (France) are typical representatives as

well as the fossil citharid genus Rhombocitharus

with the three species – R. circularis (Lower

Eocene, London Basin and Aquitaine Basin), R.

biaculeatus (Middle Eocene of Belgium and Eng-

land) and R. cauneillensis (Upper Eocene of the

Aquitaine Basin). The Bothidae are represented

by Arnoglossus lapierrei. Finally, there are two

records of the Soleidae, both from the Pardachirus

Group – Praearchirolithus schultzei and Pseudop-

ardachirolithus nolfi – both from the Upper Eocene

of the Paris Basin.

Although representing typical Pleuronecti-

formes these earliest otolith records are interpret-

ed as being relatively close to the “root” of flat-

fishes phylogenetically, as indicated by their very

plesiomorphic features. However, the Arnoglos-

sus species and the two species of the Pardachirus

Group already exhibit a surprisingly “modern”

otolith morphology. In any case, they confirm the

presence of true Pleuronectiformes as far back as

the early Tertiary. Likewise, the earliest skeleton-

based fossil records of the order Pleuronecti-

formes date back to the Middle Eocene at least

(see NORMAN 1934 and ANDREWS, GAR-

DINER, MILES & PATTERSON 1967), where they

are represented by Psettodidae s.l., Bothidae and

Soleidae.

Oligocene and Neogene – North Sea Basin (Bel-

gium, Netherlands and Germany).

References: KOKEN 1884, 1891, WEILER 1942,

1958, 1962, HEINRICH 1970, GAEMERS 1972,

1974, SCHWARZHANS 1973, 1974, 1977, 1994,

GAEMERS & SCHWARZHANS 1973, 1982,

NOLF 1976, 1978, NOLF & SMITH 1983, MEN-

ZEL 1986, MÜLLER 1994.

Throughout the Tertiary of the North Sea Basin

pleuronectiform otoliths generally are rare to very

rare, but in some strata they are still represented

by a surprising number of taxa. Their record in

the North Sea Basin proper begins in the Lower

Oligocene with a representative of the fossil ge-

nus Rhombocitharus (Citharidae) – R. rhomboides.

Their record of this lineage continues into Mid-

dle and Upper Oligocene times with the well

known R. rhenanus, and then terminates.

Sediments of the Upper Oligocene are the first

to contain a larger number of species. In view of

the then isolated situation of the North Sea Basin

the origin of the fauna is not very clear. Immigra-

tion from the Tethys via Upper Rhine Valley and

Mainz Basin does not seem to have played a major

role. The oceanic connection to the Arctic Basin

newly established in the course of late Eocene to

Oligocene history is well established geological-

ly, but can not be evaluated biogeographically

due to the total lack of any fossil otoliths from the

far northern latitudes. In any case, the indige-

nous character of the Oligocene Teleost fauna of

the North Sea Basin becomes evident immediate-

ly, when a comparison is made with contempo-

rary faunas of the European Atlantic Basins

(STEURBAUT 1984, SCHWARZHANS 1994). The

Upper Oligocene contains the following taxa (see

SCHWARZHANS 1994 for the most recent re-

view): Citharidae: Rhombocitharus rhenanus;

Scophthalmidae: Lepidorhombus subtriangularis,

Zeugopterus rosenthalensis; Bothidae: Monolene

priscus and an additional bothid (gen. and spec.

indet.); Pleuronectidae: Limanda ignobilis; Solei-

dae: Microchirus frequens (replacement for the re-

jected Solea approximata), Granulithus granum (the

latter indicative of rocky nearshore environ-

ments).

During Miocene north of Scotland a new con-

nection became established between the North

Sea and the East Atlantic. This opening facilitat-

Piscium Catalogus, Part Otolithi piscium, Vol. 2

ed to a certain extend the faunal exchange be-

tween of the two regions, which had been impos-

sible during Oligocene times. Probable immi-

grants into the North Sea Basin include Cynoglos-

sus leuchsi and Citharus sp. The latter was

originally described by WEILER (1942) as Eucith-

arus miocenicus. However, his unique type-spec-

imen was a juvenile lacking characters of true

diagnostic value and thus the species must at

present be regarded as of doubtful nature. Lepi-

dorhombus subtriangularis and possibly also Ar-

noglossus holleri were probable emigrants from the

North Sea Basin. Lepidorhombus angulosus appears

to have been restricted to the North Sea Basin, as

was still another scophthalmid – Phrynorhombus

medius. Microchirus wienrichi is also restricted to

the Miocene of the North Sea Basin. The occur-

rence of Microchirus frequens in the Miocene of

the North Sea Basin remains somewhat ques-

tionable (including the type of the now rejected

Solea approximata, see entry to M. frequens for

detailed discussion). A third Lepidorhombus spe-

cies is known from the Upper Miocene – L. klock-

enhoffi – replacing L. angulosus of the Lower and

Middle Miocene.

Plio-/Pleistocene records of flatfish otoliths

from the North Sea Basin have been placed into

recent species from the same region. From the

Pliocene the following species are here accepted

as valid: Lepidorhombus whiffiagonis, Zeugopterus

cf. punctatus, Arnoglossus laterna, Arnoglossus im-

perialis, Microchirus variegatus and Solea vulgaris.

The first “modern” pleuronectids reported from

the North Sea Basin are Hippoglossoides platessoides

from the Pleistocene of Belgium and Limanda

limanda, Pleuronectes platessa and Platichthys flesus

from the Pleistocene of southern England. In view

of their abundance in the Recent North Sea this

very late appearance of a Pleuronectidae is par-

ticularly amazing.

In summary, the North Sea Basin contained a

rich flatfish faunal component since Oligocene

times at least, although abundance of otoliths is

much less than would be expected from the

present day picture. Some fossil taxa relate well

to the recent fauna, for instance the Scophthalmi-

dae, Arnoglossus of Bothidae or Microchirus of

Soleidae, others do not (particularly in respect to

the lack of fossil Pleuronectidae). In total 19 spe-

cies are accepted as valid records from the Oli-

gocene to the Pleistocene. There are 7 fossil spe-

cies from the Oligocene and 8 from the Miocene

(2 of which occurring in both strata). 6 species

recorded from the Plio-/Pleistocene all represent

extant species.

Oligocene – Mainz Basin (Germany).

References: KOKEN 1891, SCHWARZHANS

1994.

Rhombocitharus rhenanus (Citharidae) from the

Middle Oligocene is the only pleuronectiform

recorded so far from this small basin. For a short

period during the Middle Oligocene a marine

fairway led through the Mainz Basin connecting

the North Sea Basin to the Bavarian Basin and the

Paratethys. R. rhenanus represents a lineage well

known from the North Sea since at least Early

Oligocene times. Its occurrence in the Mainz Ba-

sin is therefore regarded as due to immigration

from the north.

Oligocene and Miocene – Atlantic Basins (France

and Portugal).

References: PRIEM 1914, JONET 1973, LANCK-

NEUS & NOLF 1979, STEURBAUT 1979, 1984,

STEURBAUT & JONET 1981.

The Aquitaine Basin in SW-France and the

Lusitanian Basin in Portugal have yielded a com-

paratively rich flatfish otolith fauna, representing

practically every family except for the Pleuronec-

tidae. 16 species are tentatively regarded as valid.

From Lower Oligocene strata of the Aquitaine

Basin 5 species have been recorded: Brachypleura

pentagonalis (Brachypleuridae), Citharus sp. (also

Upper Oligocene and Lower Miocene) and an

undescribed species of the genus Rhombocitharus

(as genus Bothidarum sp. in STEURBAUT 1984),

both members of the Citharidae, Arnoglossus prud-

hommae and a possible Bothus.

The Upper Oligocene strata of the Aquitaine

Basin are less rich: except for Citharus sp. (see

above) they have yielded Pseudopardachirolithus

sulci and a second soleid, Microchirus frequens.

Lower Miocene pleuronectiform are known

from both the Aquitaine and the Lusitanian Ba-

sin. Otoliths that I had collected from the type-

localities in the Lusitanian Basin contained two

Arnoglossus species, A. taureri and A. holleri, one

citharid, Citharus lusitanicus, three soleids, Dico-

loglossa patens, Microchirus kirchbergeanus and an

undescribed species of Quenselia and one cyno-

glossid, Cynoglossus leuchsi. – The Lower and

Middle Miocene from the Aquitaine Basin is rich-

er in pleuronectiforms: Psettodes sp., Citharus lusi-

tanicus, Arnoglossus holleri, Microchirus frequens,

an undescribed Quenselia, Pseudopardachirolithus

Schwarzhans: Pleuronectiformes

sulci, Solea rotunda, Dicologlossa patens and Cyno-

glossus leuchsi. Arnoglossus taureri seems to be

missing and Microchirus kirchbergeanus may be

replaced by Microchirus frequens (if these two

species can really be reliably differentiated). The

Miocene pleuronectiform assemblages from the

Atlantic European Basins bear a remarkable re-

semblance to the contemporary fauna of the

northern Paratethys. Except for Solea rotunda and

Pseudopardachirolithus sulci which are indigenous

to the Aquitaine Basin and Microchirus frequens,

which might be an immigrant from the North

Sea Basin, all these species are likewise known

from the Paratethys. Cynoglossus leuchsi, a spe-

cies that has been described under a different

name from each basin where it occurs, has even

migrated into the North Sea.

Citharus lusitanicus, an Arnoglossus sp. and a

species tentatively assigned to Quenselia cornuta

(described as new from the Lower Pliocene of

Morocco) are obtained from the Upper Miocene

of Portugal.

Upper Miocene and Pliocene – Mediterranean

(Spain, France and Italy).

References: BASSOLI 1906, SANZ ECHEVERRIA

1950, BAUZA RULLAN 1955, SCHWARZHANS

1978, 1986, ANFOSSI & MOSNA 1979, NOLF &

MARTINELL 1980, NOLF & CAPPETTA 1980,

1988, NOLF & STEURBAUT 1983.

From the Upper Miocene of the Mediterrane-

an 4 species are accepted as valid: Citharus schu-

berti, Arnoglossus kokeni, Dicologlossa patens and

Cynoglossus leuchsi. There is also a possibly unde-

scribed Microchirus (as Solea sp. in NOLF & CAP-

PETTA 1980 and as Buglossidium sp. in NOLF &

STEURBAUT 1983). The Lower Pliocene has

yielded two species of Citharus – C. schuberti and

C. balearicus – and in addition a third citharid –

Paracitharus angustus. Other species recorded are

Arnoglossus kokeni (also described as A. bauzai from

the Late Pliocene), Dicologlossa patens and Micro-

chirus sp. (as M. variegatus in NOLF & CAPETTA

1988). The richness in citharids probably reflects

the predominance of deeper marine sediments

from which most of the described faunas have

been collected. In particular Citharus schuberti may

very well represent a deep water species replac-

ing the more shallow Citharus balearicus. Paracith-

arus angustus was found in a true deep water

sediment deposited below at least 500 m water

depth. It represents a genus nowadays endemic

to waters around South Africa.

Miocene – Vienna, Pannonian and Bavarian Ba-

sins (Austria, Hungary, Czechia, Slovakia, south-

ern Poland and southern Germany).

References: SCHUBERT 1906, 1912, WEINFURT-

ER 1952a,b, WEILER 1955, SMIGIELSKA 1973,

NOLF 1981, RADWANSKA 1984, 1992, REI-

CHENBACHER 1988.

Middle Miocene sediments (Badenian) of

these basins, which represent the northern por-

tion of the former Paratethys have proven to be

relatively rich in pleuronectiform otoliths. The

following 15 species are accepted as valid: Cith-

aridae: Citharus lusitanicus; Scophthalmidae:

Scophthalmus sp., Lepidorhombus aff. subtriangula-

ris

; Bothidae: Pseudorhombus weinfurteri, Syacium

syacioides, Laeops splendens, Arnoglossus holleri,

Arnoglossus taureri, Grammatobothus radwanskae;

Soleidae: Microchirus kirchbergeanus, Microchirus

latior, Solea rotunda, Bathysolea polonica, Dicologlos-

sa patens; Cynoglossidae: Cynoglossus leuchsi. Lep-

idorhombus aff. subtriangularis and Arnoglossus

holleri might have been immigrants from the

North Sea Basin, whereas Pseudorhombus, Syacium,

Grammatobothus and Laeops probably have south-

ern links judging from the recent distribution

pattern of the genera. Most other species except

for Microchirus latior have been found widely

distributed throughout Miocene European sedi-

ments. The Middle Miocene of the northern Pa-

ratethys thus ranks as one of the richest fossil

pleuronectiform faunas known so far.

From the Lower Miocene (Ottnangian and

Eggenburgian) only 2 species have been record-

ed so far: Microchirus latior and Microchirus kirch-

bergeanus both members of the family Soleidae,

the latter also known from otoliths “in situ”.

Upper Miocene and Lower Pliocene – Caspi Ba-

sin (Kazakhstan)

References: POBEDINA 1954, SUZIN 1968.

The fauna from the southern Paratethys is of

great interest both biogeographically and histor-

ically as far as the roots of the present day en-

demic Caspian fish fauna are concerned. POBEDI-

NA and SUZIN described no less than 9 otolith-

based species which they regarded as some kind

of pleuronectiform (mostly placed in Rhombus and

Solea). I was not able to investigate their type-

material and, unfortunately, their drawings are

not detailed enough to permit an interpretation

or even review. It seems that many species were

based on juveniles and therefore must be regard-

ed as of doubtful identity. At least two are not

Piscium Catalogus, Part Otolithi piscium, Vol. 2

pleuronectiforms. In only one case I feel confi-

dent that the figured specimen might indeed be

a good and diagnostically valid pleuronectiform

otolith, possibly a pleuronectid. This is “Rhom-

bus” altus POBEDINA 1954. Although the number

of species is certainly exaggerated there may very

well be additional pleuronectiform representa-

tives amongst the other “more doubtful” species.

4.3.3 NW-Africa

Lower Pliocene – NW-Morocco.

So far very little is known of the fossil otoliths

from Africa. A still largely undescribed fauna from

the Lower Pliocene of the Rharb Embayment in

NW-Morocco has yielded a relatively rich pleu-

ronectiform assemblage with 7 species: Cithari-

dae: Citharus balearicus; Bothidae: Arnoglossus ko-

keni, Arnoglossus quadratus, Laeops rharbensis; So-

leidae: Quenselia cornuta; Cynoglossidae:

Cynoglossus obliqueventralis, Symphurus nigrescens

(also Recent in the area). Two species, namely

Citharus balearicus and Arnoglossus kokeni, are also

known from time equivalent sediments of the

European Mediterranean Basin. All the other

species seem to be indigenous to NW-Africa. To

me, this comes as a surprise, since from the geo-

graphical location of the Rharb Embayment close

to the Strait of Gibraltar one certainly would have

expected a much closer correspondence between

the two faunas. Similar observations, however,

have been made with other Teleost groups repre-

sented in both faunas: Pterothrissidae

(SCHWARZHANS 1981), Myctophidae and Acro-

pomatidae (SCHWARZHANS 1986) and Sciaeni-

dae (SCHWARZHANS 1993). The most likely

explanation for this phenomenon in my opinion

is that the subtropical temperature belt, which

today is sharply limited south of the Canary Cold

Water Current (Mauritania), extended in Early

Pliocene times much further to the north to some-

where between the Rharb Embayment and the

Strait of Gibraltar. This interpretation is support-

ed by the close relation of the Lower Pliocene

otoliths from the Rharb Embayment with the

Recent ones from tropical West Africa. Still the

degree of persistent species from Early Pliocene

times is amazingly low in all the Teleost groups

so far analysed. It thus seems quite possible that

the Lower Pliocene Teleost fauna from NW-Mo-

rocco represents an extinct biogeographical sub-

province of the former West-African bioprovince

that vanished after the establishment of the Ca-

nary Cold Water Current.

4.3.4 Indopacific

References: FROST 1925, VORSTMANN 1927,

POSTHUMUS 1929, HATAI 1965, OHE 1981,

1983, NOLF & BAJPAI 1992.

Fossil otoliths from Indonesia and Japan have

been described rather erratically. Some have been

allocated to the Pleuronectiformes, but they all

need thorough revision. Unfortunately, I was not

in a position to inspect most of the specimens,

except for the ones described by NOLF & BAJPAI

from the Upper Eocene of Java. They are rede-

scribed here as genus aff. Brachypleura xenosulcis.

The remainder of this Indopacific summary forms

a very preliminary review. VORSTMANN (1927)

described three fossil pleuronectiform otolith

species from the Upper Eocene of Java. One of

these apparently represents a member of the fam-

ily Congridae (Anguilliformes), the two other can

not be evaluated from his figures. POSTHUMUS

(1929) and FROST (1925) recorded a total of three

pleuronectiform species from the Neogene of

Sumatra. The one described by POSTHUMUS is

probably not a pleuronectiform. The figures of

the two other species by FROST are so poor that

it is impossible to say whether or not they repre-

sent pleuronectiforms at all. The indications are

that, the Indonesian Tertiary is relatively rich in

pleuronectiform otoliths, but the unfortunate sit-

uation with FROST’s, VORSTMANN’s and

POSTHUMUS’ early publications prohibits any

further interpretation of the data.

Pleuronectiform otoliths also seem to be quite

common in the Pliocene of Japan. HATAI (1965)

described two fossil species. His photographs are

so minute and of such poor quality that any eval-

uation of his data without review of the original

material is impossible. Subsequently OHE (1981,

1983) described a further series of pleuronecti-

form otoliths from the Pliocene of Japan. He

placed all of his fossil specimens into recent taxa,

some even in taxa now restricted to European

waters. Those allocations are at least highly sus-

pect and judging from his photographs they are

indeed erroneous. Some of the other allocations,

many based on eroded or juvenile specimens, are

doubtful as well. Judging from his figures I have

tentatively accepted the following species as val-

id (OHE’s interpretations are included in brack-

Schwarzhans: Pleuronectiformes

ets): Bothidae: Paralichthys aff. olivaceus (as Arno-

glossus cf. laterna), Pseudorhombus sp. (as Solea cf.

solea), Tarphops (n.)sp. (as Chascanopsetta cf. lugu-

bris and Pseudorhombus pentophthalmus); Pleu-

ronectidae: Clidoderma asperrimum (as Lyopsetta cf.

exilis), Pleuronichthys cornutus; Soleidae: Pardachi-

rus cf. pavoninus; Cynoglossidae: Cynoglossus bi-

lineata, Cynoglossus japonica, Cynoglossus cf. joyneri.

4.3.5 New Zealand

References: SCHWARZHANS 1980 (1984),

GRENFELL 1984.

Pleuronectiform otoliths are not uncommon

in the Tertiary strata of New Zealand. In fact,

some of the Neogene species can be quite com-

mon at locations. FROST and STINTON (various

publications) have been the first to report fossil

flatfish otoliths from New Zealand and Austral-

ia, but an in-depth revision of their type-material

(SCHWARZHANS 1980) has revealed that none

represents a true pleuronectiform. Nevertheless,

species described by SCHWARZHANS, by

GRENFELL and those described as new in the

descriptive section which follows, amount to a

total of 11 species. The earliest record is Arnoglos-

sus extremus from the Upper Eocene. The next is

Arnoglossus longus in the Upper Oligocene and

Lower Miocene. Five additional bothids occur in

the Lower Miocene – genus aff. Rhombocitharus

novaezeelandiae, Grammatobothus awamoaensis, Ar-

noglossus novus (also known from the Middle

Miocene), Caulopsetta arnoglossoides and Taeniopset-

ta dorsolobata. In the Lower and Middle Miocene

the first representatives occur of those endemic

genera which nowadays are so characteristic for

New Zealand – Caulopsetta arnoglossoides and

Peltorhamphus fordycei. The richest assemblage so

far is recorded from the Lower Pliocene with

Arnoglossus grenfelli, Pelotretis sp., Samaris valid-

us, Peltorhamphus flexodorsalis and Peltorhamphus

tenuis. Of these, Arnoglossus and Samaris are not

now represented in the New Zealandian fauna.

Peltorhamphus tenuis represents a recent species

from New Zealand and is now also evident from

the Lower Pliocene.

In contrast to the relatively rich fossil pleu-

ronectiform fauna from New Zealand, the Terti-

ary strata from southern Australia have so far not

yielded a single flatfish otolith (SCHWARZHANS

1985). However, these sediments have not been

searched for otoliths quite as extensively.

5.1 Characterisation of

Pleuronectiformes otoliths

Otoliths of the order Pleuronectiformes are char-

acterised by the circumsulcal depression (for ex-

planation see chapter 6.1.). This character may

not always be very distinctively developed or it

may be disrupted behind the caudal tip, but it

remains the only true synapomorphic character

found in all otoliths of this order.

Otherwise, pleuronectiform otoliths show a

bipartite sulcus divided into an ostium and a

cauda (with very few exceptions). Proportions of

ostium and cauda are variable. Usually, the os-

tium is longer than the cauda, but in some groups

(Psettodidae, Citharidae, Tephrinectes, Paralich-

thodes, Ammotretis Group) it is shorter or equal in

length. The ostium may open anteriorly, but more

commonly its opening is pseudoostial or com-

5. Phylogenetic usage of Pleuronectiformes otoliths

pletely reduced. The cauda is usually straight and

not particularly narrower than the ostium, but in

Psettodidae, Tephrinectes, Paralichthodes and few

other genera it is distinctly narrower and with a

somewhat inclined tip.

5.2 The origin of the Pleuronectiformes

and their outgroup relationship

Since REGAN (1913) and NORMAN (1934) the

Pleuronectiformes have been understood as be-

ing derived from some kind of percoid ancestor.

This view has remained unchanged since then.

NORMAN (1934) has discussed at length his rea-

soning for regarding them as related to the Per-

ciformes putting particular emphasis on the anal-

ysis of the genus Psettodes (Psettodidae), which

he regarded as the most primitive representative

Piscium Catalogus, Part Otolithi piscium, Vol. 2

of the flatfishes. He found that “apart from the

asymmetry and the long dorsal and anal fins,

Psettodes might almost be placed in the percoid

family Serranidae”. Amongst other characters, he

used otolith evidence as illustrated by FROST

(1930).

Analyses of the otolith morphology strongly

support this concept of Psettodes relationships.

And otoliths of the genus Psettodes are indeed

amongst the most plesiomorphic of the order

(other plesiomorphic looking otoliths being the

ones of Tephrinectes, Paralichthodes, the Ammotretis

Group and the Citharidae s.s.). Psettodes otoliths

are characterised by the following features regard-

ed as plesiomorphic:

– the distinct anterior opening of the sulcus;

– the cauda being longer and considerably nar-

rower than the ostium;

– the cauda showing an inclined caudal tip;

– the circumsulcal depression being disrupted

behind the caudal tip.

This kind of otolith morphology is found in

many “basal” Percoidei as well. The only charac-

ter distinguishing Psettodes from any percoid and

combining it with the rest of the Pleuronecti-

formes is the presence of the (yet incomplete)

circumsulcal depression. FROST (1930) appreci-

ated the close resemblance of percoid and psetto-

did otoliths stating that “the otolith of Psettodes

erumei resembles in every feature those of the

suborder Percoidea”. In particular he found a

good relation with otoliths of the Percidae and

Centropomidae. SCHWARZHANS (1978, 1980)

also argued that the otolith morphology of prim-

itive Pleuronectiformes (of the Psettodidae) most

likely derived from some percoid ancestor. I then

found particularly close resemblance between

otoliths of Psettodes and those of certain genera of

Centrarchidae (a freshwater percoid family of

North America) and wrote that “Micropterus and

Psettodes can hardly be distinguished on the ge-

neric level”. Later (1995) I hypothesised that the

circumsulcal depression of pleuronectiform oto-

liths (in particular its ventral part) may have orig-

inated from the “doubled” ventral line seen in

certain basal Percoidei (for instance Acropomati-

dae or Centrarchidae). – In conclusion, the close

correspondence between the otoliths of the Pset-

todidae and those of “basal” percoids, together

with the indications from psettodid otolith mor-

phology of their most plesiomorphic position

among flatfishes, lend strong support to the con-

cept of Pleuronectiformes having derived from a

percoid ancestor. However, it may be premature

at this stage to speculate which family or “group”

of percoids would represent the closest relative.

Apart from the percoid relationship of the Pset-

todidae it has been debated in the ichthyological

literature, whether the Pleuronectiformes as a

whole represent a truly monophyletic unit or a

polyphyletic assemblage. Each of the three sub-

orders (Psettodoidei, Pleuronectoidei and Soleoi-

dei) have been suspected of having originated

independently and from “different parts” of a

percoid stock. NORMAN (1934) discussed this

matter at length and reached the conclusion that

“the evidence suggests that the Heterosomata

(Pleuronectiformes) represent a homogenous

group, although it is just possible that the Solei-

dae and Cynoglossidae may have arisen from

another part of the percoid stem”; and that “if the

flatfishes have derived from a percoid stock, then

Psettodes provides just that intermediate stage

which might be expected”. – His conclusions say

it all. Based on otolith studies there is absolutely

no argument against this view. Otoliths of the

Psettodidae, Citharidae, Brachypleuridae, Scoph-

thalmidae, Bothidae and Pleuronectidae can all

be linked in a convincing morphological-evolu-

tionary succession as has already been pointed

out by FROST (1930). Otoliths of the Soleidae and

Cynoglossidae indeed seem to be somewhat sep-

arated from the rest of the Pleuronectiformes, but

in principal their morphology is still in good ac-

cordance with that of the other families of the

order.

5.3 Pleuronectiform “grouping” according

to their otolith morphology

5.3.1 Evolutionary trends in pleuronectiform

otolith morphologies

The otoliths of the Pleuronectiformes as a group

are characterised by a certain tendency towards

reduction or “simplification” of the morphologi-

cal pattern (although certain “specialised” pat-

terns are to be found as well). This trend is likely

to reflect some kind of functional morphological

adaptation similar to those observed in other

benthic fishes (see also chapter 6.1). What exactly

has caused this development remains unknown

at present.

Schwarzhans: Pleuronectiformes

When comparing otoliths of the most primi-

tive groups (Psettodidae, Citharidae, Tephrinectes,

Paralichthodes, Ammotretis Group) with that of

“intermediate” forms (Scophthalmidae, Brachy-

pleuridae, Achirinae and certain genera of the

Bothidae and Pleuronectidae) and finally the most

derived forms (many Bothidae and Pleuronecti-

dae, Soleinae, Pardachirinae and Cynoglossidae)

a number of morphological “simplification

trends” become apparent. They are the follow-

ing:

– Reduction of the inclination of the caudal tip

to form a straight cauda;

– Reduction of the ostial opening;

– A change of sulcus proportions so that the

cauda, which is originally longer than the

ostium, first reaches the same length as the

ostium and finally becomes considerably

shorter;

– An adjustment of ostial and caudal width;

– A tendency towards the fusion of the ostial

and the caudal colliculi.

These “simplification” trends apparently have

occurred parallel and independently in several

pleuronectiform lineages, again suggesting their

adaptive functional morphological nature.

In contrast to this development there are only

few “specialisation trends”:

– The continuous development of the circum-

sulcal depression;

– Special sulcus morphologies observed in the

Syacium and Citharichthys Groups (of Bothi-

dae) and the Cynoglossidae (see chapter 6.1

for explanation).

In many instances this morphological develop-

ment reflects, in my opinion, true evolution (see

next chapter and entries for specific Groups for

more details). A particularly well documented

example is the following supposedly phyloge-

netic succession starting with the Psettodidae:

– Psettodidae – Tephrinectes (and possibly also

Paralichthodes) – Citharidae – Scophthalmi-

dae – Bothidae (Paralichthyinae).

5.3.2 Definition of suborders, families

and genus groups according

to otolith morphologies

(Fig. 1)

Ichthyological studies of flatfishes have almost

exclusively been based on meristic, morphomet-

ric and osteological analyses of the fishes them-

selves. To the best of my knowledge NORMAN

(1934) has been the only one to consider otoliths

at all. Since the present study of pleuronectiform

otoliths represents the first comprehensive one

of its kind it is only natural that one of its tasks

is to test the traditional ichthyological classifica-

tion of the group by incorporating the results of

otolith analyses. However, since the Teleostei have

become a prime play ground for cladistic analy-

ses the understanding of pleuronectiform inter-

relationships and definition of families (and sub-

families) has undergone a number of changes in

recent years (LAUDER & LIEM 1983, HENS-

LEY & AHLSTROM 1984 and CHAPLEAU 1993).

These and other published analyses are taken into

consideration and are discussed in the introduc-

tionary chapters to the larger systematic units and

are summarised in the following chapter (5.4).

The grouping of the Pleuronectiformes pre-

sented in this treatise is principally based on oto-

lith morphology. Wherever possible, I have used

available family names to which I have assigned

my otolith groups (genus groups). The only ex-

ceptions are the Brachypleuridae, formerly re-

garded as a subfamily of the Citharidae and here

understood as a separate family, and the genera

Tephrinectes, Paralichthodes and those of the Am-

motretis Group. The latter are removed from their

position in the Bothidae and Pleuronectidae re-

spectively and are placed in a category of uncer-

tain family affinities. The three generic groups in

question may not be related to each other. Ac-

cording to otolith morphology, however, they

exhibit a decisively plesiomorphic pattern that

indicates an early phylogenetic separation from

the main evolutionary branches of the Pleuronec-

toidei (i.e. Bothidae and Pleuronectidae). The

various and changing concepts of subfamilies (or

separated families) in the Bothidae, Pleuronecti-

dae and Soleidae are being used in an informal

way only and in essence are replaced by “genus

groups” based on otolith morphology. I feel that

the loose assignment in genus groups more accu-

rately reflects the taxonomic information that can

be gained from otoliths. The genus groups as

defined below usually represent smaller units

than the subfamilies in use. The intention has

been to break down the vast number of genera to

form clusters which based on otolith analysis look

similar and may in fact represent homogenous

groups. The interrelationship of the various ge-

nus groups on the other hand is much less well

defined. However, in most instances they can be

Piscium Catalogus, Part Otolithi piscium, Vol. 2

PSETTODIDAE Fam. indet. Fam. indet.

CITHARIDAE BRACHYPLEURIDAEFam. indet.

BOTHIDAE

SCOPHTHALMIDAE

Psettodes Tephrinectes Paralichthodes

Ammotretis Citharus Brachypleura

Scophthalmus Zeugopterus ParalichthysLepidorhombus

Pseudorhombus Syacium Citharichthys

Bothus Monolene-Laeops EngyprosoponArnoglossus

Thysanopsetta Chascanopsetta Mancopsetta

Schwarzhans: Pleuronectiformes

Fig. 1: Pleuronectiform otoliths – quick look interpretation chart.

(Generic names below figures refer to otolith groups.)

Hippoglossus Hippoglossoides Glyptocephalus

PLEURONECTIDAE

Pleuronectes-Limanda Isopsetta Verasper

Microstomus-Pleuronichthys Samaris PoecilopsettaMarleyella

Pelotretis Rhombosolea ApionichthysAchirus

SOLEIDAE

Solea Synaptura ZebriasBrachirus

Pardachirus Heteromycteris SymphurusCynoglossus

CYNOGLOSSIDAE

Piscium Catalogus, Part Otolithi piscium, Vol. 2

grouped conveniently in existing subfamilies (or

“super”-groups). In the light of the rapidly chang-

ing classification concepts in Pleuronectiformes

as a result of the various recent phylogenetic and

cladistic studies I have adhered to the more con-

servative view of pleuronectiform family group-

ing of NELSON (1984). Other findings forward-

ed in HENSLEY & AHLSTROM (1984), CHAP-

LEAU (1993) and their adoption in NELSON

(1994) are nevertheless discussed and compared

with otolith-based groupings (see chapter 5.4).

I must stress the point that the otolith genus

groups introduced here have the character of a

“working hypothesis” aimed to give some help

when arranging all the diverse otolith morphol-

ogies in this order. The work is certainly not in-

tended to introduce a new “official” subclassifi-

cation of the families of the order Pleuronecti-

formes in the sense of subfamilies or tribes.

The following table gives a guide of how the

otolith genus groups described (third row) fit into

the traditional classification of the Pleuronecti-

formes (first row, composed from NORMAN

1934, CHABANAUD 1939 and NELSON 1984)

and the more recent classification based on cla-

distic analyses (second row, adopted from NEL-

SON 1994 after HENSLEY & AHLSTROM 1984

and CHAPLEAU 1993).

Classification

combined from combined from

NORMAN (1934), HENSLEY & AHLSTROM (1984) Otolith grouping

CHABANAUD (1939) CHAPLEAU (1993) as proposed in this paper

and NELSON (1984) and NELSON (1994)

Psettodoidei

Psettodidae Psettodidae Psettodidae

Pleuronectoidei

– – genera of uncertain relationship:

(ex Bothidae) (ex Paralichthyidae) Tephrinectes Group

(ex Pleuronectidae) (ex Pleuronectidae) Paralichthodes Group

(ex Pleuronectidae) (ex Pleuronectidae) Ammotretis Group

Citharidae Citharidae

Citharinae – Citharidae

Brachypleurinae – Brachypleuridae

Scophthalmidae Scophthalmidae Scophthalmidae

Scophthalmus Group

Lepidorhombus Group

Zeugopterus Group

Bothidae Paralichthyidae Bothidae

Paralichthyinae – Paralichthys Group

(excluded: Tephrinectes, (excluded: Pseudorhombus Group

Thysanopsetta, Monolene, Tephrinectes, Citharichthys Group

Engyophrys, Trichopsetta) Thysanopsetta) Syacium Group

(fam. indet.) Tephrinectes Group

Bothinae Bothidae Bothus Group

Arnoglossus Group

Monolene-Laeops Group

Engyprosopon Group

Thysanopsetta Group

Chascanopsetta Group

Achiropsettidae Mancopsetta Group

Pleuronectidae Pleuronectidae Pleuronectidae

Pleuronectinae Pleuronectinae Hippoglossus Group

Hippoglossoides Group

Schwarzhans: Pleuronectiformes

Glyptocephalus Group

Pleuronectes-Limanda Group

Isopsetta Group

Verasper Group

Microstomus-Pleuronichthys Gr.

Poecilopsettinae Poecilopsettinae Marleyella Group

Poecilopsetta Group

Paralichthodinae Paralichthodinae (fam. indet.) Paralichthodes Group

Samarinae Samaridae Samaris Group (incl. Azygopus

ex Rhombosoleinae)

Rhombosoleinae Rhombosoleinae Pelotretis Group

Rhombosolea Group

excluded genera:

(fam. indet.) Ammotretis

Group (Soleidae) Peltorham-

phus (Samarinae) Azygopus

Soleoidei

Soleidae Achiridae Soleidae

Achirinae Achirus Group

Apionichthyinae Apionichthys Group

Soleinae Soleidae Solea Group

Synaptura Group

Brachirus Group

Zebrias Group

Pardachirinae Pardachirus Group

Heteromycterinae Heteromycteris Group (incl.

Peltorhamphus ex Pleuronect.)

Cynoglossidae Cynoglossidae Cynoglossidae

Cynoglossinae Cynoglossinae Cynoglossus Group

Symphurinae Symphurinae Symphurus Group

The traditional classification of the Pleuronecti-

formes is based on several characters, the most

widely used ones being the position of the optic

nerve of the migrating eye and the side on which

the eyes are located. In the Psettodoidei and So-

leoidei the optic nerves are crossed, which is

thought to be a plesiomorphic character, whereas

in the Pleuronectoidei the optic nerve of the mi-

grating eye is always dorsal. In the Psettodidae

(and Tephrinectes too) the eyes can be sinistral or

dextral. The Citharidae were defined by the po-

sition of the anus on the eyed side and the pres-

ence of 1 spine in the pelvic fins. In the subfamily

Citharinae the eyes are sinistral, whereas in the

Brachypleurinae they are dextral. Scophthalmi-

dae and Bothidae have sinistral eyes, Pleuronecti-

dae dextral eyes. The Scophthalmidae are char-

acterised by the elongate pelvic fin base. The two

bothid subfamilies Paralichthyinae and Bothinae

are defined by the presence or absence of

branched pectoral and pelvic rays and symmetry

or asymmetry of pelvic fin bases. In the suborder

Soleoidei again the two families are distinguished

by the position of the eyes:- in Soleidae eyes are

dextral, in Cynoglossidae eyes are sinistral.

In the following paragraphs I have briefly

summarised the otolith characters used to distin-

guish the families and the otolith genus groups.

For more detailed discussions see respective en-

tries to families and genus groups.

Psettodid otoliths are defined by a combina-

tion of very plesiomorphic characters (see descrip-

tion in chapter 5.2).

The genera Tephrinectes (ex Bothidae), Paralich-

thodes (ex Pleuronectidae) and those of the Ammo-

tretis Group (ex Pleuronectidae) exhibit a similar-

ly plesiomorphic otolith pattern. This is also the

reason, why they are here removed from the fam-

Piscium Catalogus, Part Otolithi piscium, Vol. 2

ilies in which they have traditionally been placed

and put in a category of uncertain relationship in

an open familial status. They may in fact not be

closely related, representing various early evolu-

tionary “spin-offs” from the main pleuronectoid

branches. Tephrinectes differs from Psettodes sole-

ly in the ostium to cauda ratio, which is nearly 1.

In Psettodes and Paralichthodes the cauda is con-

siderably longer than the ostium. Paralichthodes

otoliths are remarkable for their extremely faint

ventral portion of the circumsulcal depression and

the rather strong inclination of the caudal tip, the

strongest of its kind found in the Pleuronecti-

formes. Otoliths from the Ammotretis Group are

quite different from those of any other pleuronec-

tiforms. They show a clear sulcus opening, a cau-

da that is narrower than the ostium and about

equal in length, sometimes with a peculiar point-

ed tip, and a very faint and incomplete circum-

sulcal depression. This pattern must be regarded

as decisively plesiomorphic despite the apomor-

phic appearance of the fishes themselves. If found

isolated and without knowledge of the recent fish

from which they were dissected one would hard-

ly recognise otoliths of the Ammotretis Group as

belonging to the Pleuronectiforms. In conclusion,

I would suggest from otolith analysis that the

Ammotretis Group is of pre-pleuronectid origin

and should be separated from the Pleuronectidae

and put in a family of its own.

In the Citharidae ostium and cauda are of

about the same length, but the cauda is much

narrower than the ostium. Morphologically, these

otoliths occupy an intermediate stage between

the very plesiomorphic otoliths of the Psettodi-

dae and the more specialised ones of the “higher

Pleuronectoidei”, which is in accordance with the

position this family occupies in the cladogram of

LAUDER & LIEM (1984) (see chapter 5.4).

Brachypleurid otoliths differ from citharids

in the short cauda with its rounded tip, equally in

width with the ostium and the anteriorly reduced

sulcus opening, which are all apomorphic fea-

tures. The genus Brachypleura is more advanced

than Lepidoblepharon in many aspects of the oto-

lith morphology. The rostrum is strongly reduced.

A unique feature is also the slight ventral expan-

sion of the collum (see chapter 6.1. for explana-

tion; incipiently so in Lepidoblepharon). In outline,

the compressed Brachypleura otoliths with their

strong predorsal lobe resemble those of certain

Soleidae. Lepidoblepharon otoliths in outline resem-

ble more citharid otoliths. This, however, is re-

garded as a plesiomorphic feature indicating basal

relationship of the two families.

Scophthalmid otolith morphologies are quite

divergent. That of the Scophthalmus Group resem-

ble psettodids or citharids but with a cauda much

more reduced in length. Lepidorhombus appears

to fit perfectly within the Bothidae and is remark-

able for its extreme side dimorphism in otoliths.

Otoliths of the Zeugopterus Group look like

“dwarfed” Scophthalmus otoliths, but with a cau-

da less reduced in length. The ostial opening in

all Scophthalmidae is either present or only very

slightly reduced.

Bothid otoliths display a wide variety of pat-

terns. Recognition of bothid otoliths depends on

correlation with and assignment to a certain oto-

lith genus group. In general terms, however, two

major morphological groupings are readily dis-

tinguishable, to which subfamily ranking is here

applied:

1. One group with relatively thin, large and

mostly flat otoliths with a moderately to

strongly reduced sulcus opening. This “su-

pergroup” roughly corresponds to NOR-

MAN’s Paralichthyinae, but much better to

HENSLEY & AHLSTROM’s Paralichthyidae.

Within this “supergroup” there is one partic-

ularly well established morphological-evolu-

tionary trend starting with Paralichthys and

Lioglossina leading to the Pseudorhombus

Group

and then to the Citharichthys and Syacium

Groups. This trend is characterised by the

development of the “fusiform” sulcus outline

(see chapter 6.1).

2. The second “supergroup” comprises smaller

more compact and robust otoliths, often with

a deep sulcus and with a clear ostial or at

least pseudoostial sulcus opening. This “su-

pergroup” more or less corresponds to NOR-

MAN’s Bothinae, or the Bothidae of HENS-

LEY & AHLSTROM (1984) together with the

Achiropsettidae of HENSLEY (1986).

– The position of the Thysanopsetta, Chascano-

psetta and Mancopsetta Groups remains some-

what obscure (here included in the Bothinae

for convenience).

In pleuronectids as in bothids there is not a single

otolith character that could unambiguously be

used for definition.

– However, the various genus groups combined

in the Pleuronectinae are characterised by a

more or less strongly reduced sulcus opening

(except for the Verasper and Microstomus-Pleu-

Schwarzhans: Pleuronectiformes

ronichthys Groups, which have a clear sulcus

opening), a short cauda, a relatively smooth

inner face and a rather thin appearance.

– Otoliths of the Samaris Group (Samarinae) are

characterised by an extremely deep sulcus and

an extremely deep circumsulcal depression.

The ostium shows a distinct opening often

with a clear cut excisura. The genus Azygo-

pus, which was placed by (NORMAN 1934)

in the Rhombosoleinae is tentatively includ-

ed in this group as well.

– Otoliths of the Poecilopsettinae contain two

morphologies. That of the Marleyella Group is

rather plesiomorphic resembling citharids in

many aspects except that cauda and ostium

are of about equal width. In the Poecilopsetta

Group the sulcus morphology is more re-

duced, particularly the length of the cauda.

These otoliths are robust, round in shape, with

an ostial to pseudoostial sulcus opening. The

otolith morphology of Marleyella suggests that

the Poecilopsettinae represent a basal offshot

from the Pleuronectidae or from the Brachy-

pleuridae (Lepidoblepharon).

– Rhombosoleinae, as defined by NORMAN

(1934), seem to me to represent a catch-all

assemblage of dextral Pleuronectoidei from

the Southern Oceans. I have considerable

doubts that this subfamily really represents a

homogenous unit. NORMAN pointed out that

some rhombosolein genera resemble Soleidae,

but argued that this would be due to conver-

gence. On this point I agree with his conclu-

sions except for the genus Peltorhamphus

which shows a typical soleid sulcus pattern

(and therefore is here placed in the Soleidae).

Also the genera that I have put together in the

Ammotretis Group are here removed from the

Pleuronectidae and placed in a category of

uncertain familial relationship (see above).

Pelotretis shows rather indistinct otoliths sim-

ilar to so many pleuronectids, but also to Lepi-

dorhombus of the Scopthalmidae. Rhombosolea

has rather unique otoliths with a strongly out-

wardly curved ventral margin and the mirror

image orientation of the asymmetric charac-

ters (see chapter 6.2). Otherwise it might be

considered a pleuronectid. Otoliths of Azygo-

pus, with their very deep sulcus and deep

excisura, are quite different from other Rhom-

bosoleinae. This genus is here included in the

Samaris Group. In certain general aspects they

resemble those of the Ammotretis Group which

I have removed from the Pleuronectidae alto-

gether. To me the relationship of several so-

called rhombosolein genera, as mentioned

above, remains obscure. Only Pelotretis and

Rhombosolea in my classification remain in the

subfamily Rhombosoleinae.

Otoliths of the Soleidae are in my opinion recog-

nised quite easily, although it is difficult to say

which characters precisely make them look so

peculiar. They are compressed otoliths with a

rather regular round or oval shape, a somewhat

reduced sulcus opening and a tendency towards

a shallow sulcus and fused or at least poorly

defined colliculi. Often, their inner face is quite

convex and smooth which can best be shown in

lateral views.

– The Achirus Group corresponds to the sub-

family Achirinae and probably represents the

most plesiomorphic sulcus pattern found in

the Soleoidei. Ostium and cauda are of about

equal length or the cauda is just slightly short-

er than the ostium. The sulcus is slightly deep-

ened to considerably deepened in some gen-

era (Gymnachirus and Nodogymnus) which

show also fused colliculi. In this respect oto-

liths of the Zebrias Group, traditionally placed

in the Soleinae, are quite similar to those of

the genus Gymnachirus. Whether this resem-

blance reflects true relationship of the two

groups or just convergent evolution remains

to be tested by other characters. However, due

to the resemblance of otoliths of the genera of

the Zebrias Group to those of the Brachirus

Group I have elected to keep them in their

traditional place. – Otoliths of the Apionich-

thys Group (Apionichthyinae in CHABA-

NAUD, 1939), although not very well known,

do not seem to depart much from the pattern

found in the Achirus Group and are here in-

cluded in the Achirinae.

– The Soleinae include quite a variety of otolith

morphologies. Otoliths of the Synaptura Group

are elongate and exhibit a very special sulcus

morphology different from all other Soleoi-

dei. The cauda is short, but the ostium is bi-

partite with its anterior portion considerably

narrowed. Otoliths of the Solea Group exhibit

the typical soleid otolith pattern. The outline

of the otoliths is evenly rounded. The inner

face is convex (except for Bathysolea and Van-

straelenia which have flat inner faces). The

cauda is small, usually shorter than the os-

tium. The sulcus is not much deepened and

Piscium Catalogus, Part Otolithi piscium, Vol. 2

there is a notable tendency for a fusion of the

colliculi. Otoliths of the Brachirus Group are

similar in general appearance, but with a rath-

er flat inner face and an anteriorly narrowed

outline. The genera of the Zebrias Group are

thought to have derived from the Brachirus

Group and are characterised by flat and thin

otoliths with a rather short and deep sulcus

and fused colliculi, thus resembling certain

genera of the Achirus Group (see above).

Where not completely fused, colliculi are

about equal in length, which is the main dis-

tinction from otoliths of the Brachirus Group

(together with the anteriorly reduced ostium).

– The otoliths of the Pardachirus Group

(Pardachirinae in CHABANAUD, 1939) and

the Heteromycteris Group (Heteromycterinae

in CHABANAUD, 1939, but including the

genus Peltorhamphus ex Pleuronectidae, sub-

family Rhombosoleinae, sensu NORMAN,

1934) all look very similar. Based on otolith

morphology alone they could easily be com-

bined in a single group or subfamily, the

Pardachirinae. The characters defining this

group are a compressed outline with a deeply

curved posteriorly oriented ventral rim and a

rather flat dorsal rim, a strongly convex inner

face which is rather smooth including a shal-

low sulcus, a concave outer face, the circum-

sulcal depression often being reduced in width

and a short almost circular cauda which in

some genera exhibits a tendency to widen.

The development of the circumsulcal depres-

sion is the only character useful for distin-

guishing the members of the two genus

groups: in the Heteromycteris Group it is mod-

erately narrowed and usually runs close to

the sulcus, and in the Pardachirus Group it is

most narrowed, almost to a furrow that runs

close to the rims of the otolith. Cynoglossid

otoliths are in many respects very similar to

those of this “supergroup” (the Pardachirinae)

and in fact may very well have originated from

it. The peculiar widened cauda of the Cy-

noglossidae seems to be “foreshadowed” in

certain genera of this “supergroup”, such as

Pardachirus and even more so in Rendahlia

(Heteromycteris Group).

Cynoglossid otoliths are readily recognised

by their “hammer-shaped” sulcus (see chapter 6.1)

which has resulted from a distinctive widening

of the cauda. Ostial and caudal colliculum are

fused. In all other aspects otoliths of the Cynoglos-

sidae perfectly resemble those of the Pardachirus

and Heteromycteris Groups of the Soleidae from

where in fact they may have originated. Otoliths

of the Cynoglossus Group exhibit the more plesi-

omorphic pattern, whereas those of the Symphu-

rus Group are characterised by a further special-

isation of the sulcus outline and the circumsulcal

depression. The two groups have traditionally

been placed in two separate cynoglossid sub-

families, but I have refrained from doing so due

to the close relationship of the two groups.

Typical representatives of each of the otolith ge-

nus groups as defined in this treatise are sche-

matically outlined in a quick look interpretation

chart (fig. 1).

5.4 Discussion of phylogenetic concepts

in Pleuronectiformes

(Fig.2-4)

Until recently, NORMAN’s classification with

modifications by HUBBS (1945), AMAOKA

(1969), FUTCH (1977) and HENSLEY (1977) rep-

resented the most detailed hypothesis for pleu-

ronectiform evolution. This model is depicted in

row one of the classification list in chapter 5.3.2

and as a phylogram in figure 2. It has served as

basis for the otolith analysis of Pleuronectiformes

as presented here. However, as HENSLEY &

AHLSTROM (1984) stated: “Formation of the

(Regan-)Norman model involved an eclectic ap-

proach, i.e. a combination of phyletic and phenetic

methods. Although some of the groups (currently)

recognised appear to be based on synapomor-

phies, many are clearly based on symplesiomor-

phies and were recognised as such by the au-

thors.”

In recent years a number of publications have

been published devoted to a more cladistic phy-

logenetic interpretation of pleuronectiform rela-

tionships (or certain pleuronectiform families).

These are works by LAUDER & LIEM (1983),

HENSLEY & AHLSTROM (1984), SAKAMOTO

(1984) and CHAPLEAU (1987,1993). The results

of these analyses are briefly discussed in the fol-

lowing and are compared to the findings of ana-

lyses of the otolith morphology.

A first cladistic analysis of the Pleuronecti-

formes was presented by LAUDER & LIEM

(1983). In their cladogram the Psettodidae are

identified as the plesiomorphic sister-group of

Schwarzhans: Pleuronectiformes

all remaining Pleuronectiformes. The next dicho-

tomy separates the Citharidae (loss of spines in

dorsal and anal fins, loss of dentition on palati-

num and basihyale, tip of dorsal fin commencing

above eye). They are characterised by one sup-

posedly autapomorphic character – the shift of

the anus onto the eyed side. In the case of the

Brachypleuridae (usually accorded subfamily

rank within the Citharidae) the synapomorphic

nature of this character must be doubted. Pres-

ence of a spine in the pelvic fin separates the

Citharidae (sensu HUBBS 1945, LAUDER & LIEM

1983) from the Scophthalmidae, which are sepa-

rated next from the main branch of the Pleuronec-

tiformes. Loss of dentition on the vomer and

uniting of the branchiostegal membranes of the

two sides characterises the remaining “higher”

Pleuronectiformes from which Pleuronectidae

and Bothidae are subsequently separated as the

next units. Finally, Soleoidei are regarded as the

most advanced pleuronectiforms characterised by

the loss of the postcleithra and the ribs. And

within the Soleoidei, Cynoglossidae are the last

group to be singled out on the basis of the loss of

the pectorals (which, however, are also missing

in some Soleidae). – In the Psettodoidei and Pleu-

ronectoidei this phylogenetic interpretation large-

ly reflects NORMAN’s concept of classification

(1934) including HUBBS’ (1945) emendations.

Soleoidei, however, were then thought to repre-

sent a separate lineage from Pleuronectoidei al-

together. Fossil evidence both from skeletons and

otoliths extends back well into Eocene times (see

respective entries) and thus support the concept

of an early evolutionary separation of the Soleoi-

dei, earlier in fact than is suggested by LAUDER

& LIEM’s cladogram.

Since then further and more detailed cladistic

analyses have been published by HENSLEY &

AHLSTROM (1984) and CHAPLEAU (1993)

plus a specialised one dealing exclusively with

interrelationships of the family Pleuronectidae

by SAKAMOTO (1984) (see also NELSON 1994).

HENSLEY & AHLSTROM and CHAPLEAU

questioned the monophyly of the families Cith-

aridae and Pleuronectidae. For Citharidae CHAP-

LEAU suggested that the dextral Lepidoblepharon

and the sinistral Citharoides form a trichotomy

with all remaining Pleuronectiformes, including

the other citharid genera (the sinistral Citharus

Fig. 2: Hypothesis of interrelationships of pleuronectiform fishes presented in HENSLEY & AHLSTROM

(1984), based on NORMAN (1934), HUBBS (1945) and AMAOKA (1969)

Piscium Catalogus, Part Otolithi piscium, Vol. 2

and the dextral Brachypleura). Otoliths, however,

strongly indicate that the separation of the former

Citharidae runs between the sinistral and the

dextral genera, and in fact they are here placed in

two separate families – Citharidae and Brachyp-

leuridae. Nevertheless, in this concept Lepido-

blepharon represents the more plesiomorphic char-

acter status within the Brachypleuridae, resem-

bling Citharidae in several plesiomorphic aspects,

such as the outline of the otoliths. HENSLEY &

AHLSTROM regard Brachypleura as related to the

Scophthalmidae-Bothidae lineage because of the

hypural pattern which it shares with those but

not with the Citharidae (sensu strictu). From the

otoliths point of view, I feel unable to define which

of the two families (Citharidae and Brachypleu-

ridae) may in fact be more closely related to the

higher Pleuronectoidei (Scophthalmidae, Bothi-

dae and Pleuronectidae). They do most likely

represent a basal alignment from near which these

families may have evolved.

HENSLEY & AHLSTROM (and also CHAP-

LEAU) separated the Bothidae in the two fami-

lies Bothidae and Paralichthyidae. This separa-

tion is adopted here as well, but with subfamily

ranking. Based on the analysis of the pattern of

the hypurals HENSLEY & AHLSTROM defined

one particular pattern they referred to as the ‘bot-

hoid group’, containing Brachypleura, Scoph-

thalmidae, most Bothidae (in the sense used here)

and Pleuronectinae.

HENSLEY & AHLSTROM excluded Tephri-

nectes and Thysanopsetta from their bothoid group

stating that “these two genera are much more

primitive than expressed in the current classifi-

cation and definitely do not belong to the both-

oid group”. Also, they support the removal of the

genera Taeniopsetta, Monolene, Engyophrys and

Trichopsetta from the Paralichthyidae (here Paral-

ichthyinae) to the Bothidae (here Bothinae). With-

in the Paralichthyidae they distinguish three

groups – a plesiomorphic, possibly non-mono-

phyletic group containing the genera Ancylopset-

ta, Gastropsetta, Hippoglossina, Lioglossina, Parali-

chthys and Xystreurys and two better defined

apomorphic groups, the Cyclopsetta group with

Cyclopsetta, Syacium, Citharichthys and Etropus and

the Pseudorhombus group with Pseudorhombus,

Tarphops and Cephalopsetta. These conclusions are

in perfect agreement with the otolith findings (see

entries to the Tephrinectes Group and the Bothi-

dae and its groups).

Fig. 3: Hypothesis of interrelationships of pleuronectiform fishes redrawn

from the consensus tree diagram presented by CHAPLEAU (1992).

Schwarzhans: Pleuronectiformes

Within the Bothidae (sensu HENSLEY &

AHLSTROM, here Bothinae) two groups or sub-

families are recognised by HENSLEY & AHL-

STROM – the plesiomorphic Taeniopsettinae in-

cluding at least Taeniopsetta, Engyophrys, Trichopset-

ta and Perissias and (poorly defined) the Bothinae

for the remainder. Otolith analysis is less conclu-

sive in this group.

The genus Mancopsetta is not regarded as a

bothoid by HENSLEY & AHLSTROM because of

several primitive characters not found in the

Bothidae. EVSEENKO (1984) later erected a fam-

ily Achiropsettidae (here equivalent to the Man-

copsetta Group).

Both HENSLEY & AHLSTROM and CHAP-

LEAU regard the Pleuronectidae as non-mono-

phyletic, with the Pleuronectinae being more

closely related to the Paralichthyidae (ex Bothi-

dae). According to HENSLEY & AHLSTROM the

Pleuronectinae are the only pleuronectid subfami-

ly with a bothoid hypural pattern, thus relating

them to the Bothidae (in the sense used here) and

demonstrating the polyphyly of the Pleuronecti-

dae. Likewise, CHAPLEAU identifies the Pleu-

ronectinae as the most plesiomorphic subfamily

in Pleuronectidae and close to the Bothidae (s.l.).

Pleuronectine otoliths too show a close resem-

blance to those of the bothid subfamily Paralich-

tyinae and differ considerably from those of the

other pleuronectid subfamilies.

HENSLEY & AHLSTROM concluded that the

other pleuronectid subfamilies do not show the

bothoid hypural pattern and used this observa-

tion as an argument for the supposed polyphyly

Fig. 4: Hypothesis of interrelationships of pleuronectiform fishes according to otolith analysis as proposed in this

treatise. – Characters used for discrimination are: Inherited plesiomorphic characters: A = Dorsal depression; B =

Ostial sulcus opening; C = Ostium shorter and wider than cauda; D = Cauda curved; Apomorphic characters:

1 = Ventral depression; 2 = Cauda about equal in length to ostium; 2a = Caudal tip widened; 2b = Caudal tip

pointed; 2c = Cauda shorter than ostium; 3 = Sulcus opening pseudoostial; 3a = Sulcus closed; 3b = Secondary

sulcus opening; 4 = Cauda straight; 5 = Loss of tapering caudal tip; 6 = Circumsulcal depression complete; 7 =

High, “soleiform” outline of otolith; 8 = Collum ventrally widened; 9 = Circumsulcal depression narrow; 10 =

Hammer shaped sulcus; 11 = Colliculi fused; 11a = Colliculi partly fused. Hatched markers indicate that only

some genera of the group have developed the respective character. Note: Some of the reduced characters (such

as 4, 5, 11) apparently have occured in independent lineages.

Piscium Catalogus, Part Otolithi piscium, Vol. 2

of the Pleuronectidae. CHAPLEAU recommend-

ed that the Poecilopsettinae, Rhombosoleinae and

Samarinae be raised to familial rank. Seeing the

uncertainties for instance in the interrelationships

of the so called Rhombosoleinae (see entry to

Rhombosolea Group and Pleuronectidae) I agree

with NELSON (1994) that this classification is at

this stage premature, but the principal concept of

the Pleuronectidae being possibly polyphyletic is

supported by otolith analyses.

The Poecilopsettinae are placed in CHAP-

LEAU’s cladogram near to the Rhombosoleinae,

whereas SAKAMOTO combines them in the Pleu-

ronectinae-Poecilopsettinae stem.

The Samarinae show a number of highly spe-

cialised features both in skeleton and in otoliths.

Their interrelationships therefore presently are

much under debate. Both HENSLEY & AHL-

STROM and CHAPLEAU find arguments that

they could be related to soleoids. However, oto-

lith analysis strongly contradicts this view. The

degree and kind of otolith specialisation found in

Samarinae has nothing in common with that

observed in the Soleoidei. Furthermore, fossil

evidence seems to indicate that the Soleoidei are

a rather ancient group in pleuronectiforms and

may have split off from the other pleuronecti-

form stems much earlier than is suggested by

modern cladograms (see fig. 3, cladogram from

CHAPLEAU 1993).

Paralichthodes has usually been associated with

the Samarinae either as a separate but related

subfamily or entirely included with the Samari-

nae. Its otolith pattern is distinctly plesiomorphic

pointing to a pre-bothid/pleuronectid origin (see

entry to Paralichthodes Group), but this conclu-

sion will need further verification by other ich-

thyological investigations.

Finally, the Rhombosoleinae represent the

most enigmatic subfamily within the Pleuronecti-

dae. Except for SAKAMOTO (1984) they have

not been subject to a recent review and a phylo-

genetic analysis. In SAKAMOTO’s cladogram of

the Pleuronectidae the various rhombosoleine

genera are widely separated although he still

regards them as a distinct unit. Otolith analysis

instead clearly demonstrates the Rhombosolein-

ae not to represent a natural assemblage (see

chapter 5.3.2. and entries to Ammotretis, Samaris,

Pelotretis and Rhombosolea Groups and Soleidae).

Part of the so-called Rhombosoleinae are proba-

bly of pre-bothid/pleuronectid origin or are re-

lated to the Samarinae (Ammotretis Group and

Azygopus) and one genus (Peltorhamphus) is re-

moved to the Soleidae. As understood here, only

Pelotretis and Rhombosolea remain in the Rhom-

bosoleinae sensu strictu.

Soleoidei have been thought to form a mono-

phyletic group in recent cladistic analyses (HENS-

LEY & AHLSTROM, 1984 and CHAPLEAU,

1988). Achiridae are separated from Soleidae and

are thought to represent the primitive sister group

to Soleidae and Cynoglossidae, according to

CHAPLEAU (1993). HENSLEY & AHLSTROM

note that the Achirinae exhibit a very primitive

hypural pattern and thus assume that the Soleoi-

dei might be of rather early origin. This view is

support by the geologically early findings of so-

leoid otoliths. In contrast LAUDER & LIEM (1983)

and CHAPLEAU (1993) have separated the

Soleoidei as the latest stem from the pleuronecti-

form cladogram, branching even later than the

Pleuronectidae and close to the Samarinae. Also

the separation of Achirinae and Soleinae is sup-

ported by otolith analysis (I have left them at

subfamily rank next to Soleinae and Pardachiri-

nae).

All authors regard the Cynoglossidae as be-

ing closely related to the Soleidae. CHAPLEAU

(1993) in his cladogram separates the Achiridae

(here Achirinae) first before the dichotomy of

Soleidae and Cynoglossidae. Otoliths indeed

strongly support the concept of the Cynoglossi-

dae having derived from the Soleidae. From oto-

liths there is convincing synapomorphic evidence

that the Cynoglossidae originated from near

Pardachirinae of the Soleidae (see respective en-

tries). CHAPLEAU (1988) analysed the interrela-

tionships of the Cynoglossidae concluding the

Symphurinae (here Symphurus Group) to repre-

sent the plesiomorphic sister group of the Cy-

noglossinae (here Cynoglossus Group). Otolith

analysis, however, contradicts this view. Symphu-

rus otoliths seem to be the more specialised ones.

Maybe, the apparent plesiomorphic character of

Symphurus fishes represents a secondary reduc-

tion rather than a more primitive character state.

Conclusions:

1. The basal alignment of the Pleuronectiformes

(Psettodidae, Citharidae and Scophthalmidae)

accords well with otolith findings. However,

CHAPLEAU’s concept of the splitting of the

Citharidae is not supported. Instead, it is rec-

ommended to separate Citharidae and Brach-

ypleuridae. Also, otolith analysis suggests that

Schwarzhans: Pleuronectiformes

the basal pleuronectiform group may contain

additional taxa – the Tephrinectes, Paralichthodes

and Ammotretis Groups, here placed in a group

of uncertain familial affinities.

2. HENSLEY & AHLSTROM’s concept of sub-

dividing the Bothidae (Paralichthyinae and

Bothinae and subgroups including removal

of Tephrinectes and perhaps also Thysanopsetta

and Mancopsetta) is fully supported by otolith

analysis.

3. Otoliths support the hypothesis of the po-

lyphyly of the family Pleuronectidae, with the

Pleuronectinae more closely related to the Bo-

thidae than the other subfamilies. The relation-

ships of the other subfamilies remain cryptic.

4. According to otoliths the Rhombosoleinae do

not form a natural assembly.

5. In accordance with HENSLEY & AHLSTROM

the Soleoidei are thought to represent a natu-

ral group of quite early origin. Within the

Soleoidei the Achirinae represent the most

primitive group and the Cynoglossidae are

very likely derived from the Soleidae

(Pardachirinae).

For comparison I have figured the three main

concepts discussed as cladograms or phyllo-

grams. Fig. 2 shows the phylogram according to

NORMAN’s model (from HENSLEY & AHL-

STROM, 1984). Fig. 3 shows the cladogram of

CHAPLEAU (1993). Fig. 4 depicts the results of

the otolith analysis in the form of a cladogram, in

order to compare it to the analyses presented by

LAUDER & LIEM (1983), HENSLEY & AHL-

STROM (1984) and CHAPLEAU (1993) (fig. 2).

(Generally, I hesitate to depict assumed “otolith

relationships” as cladograms, because I feel that

any otolith based systematic suggestions should

first be tested and verified by other ichthyologi-

cal investigations.)

6.1 Terminology

(Fig. 5-13)

Pleuronectiform otoliths are not always easily

recognised as such. As stated before (see chap-

ters 5.1. and 5.3) there is a widespread tendency

within the otoliths of this order towards reduc-

tion or “simplification” of certain aspects of their

morphology. Sulcus morphology and outline of

the otolith are the characters most commonly af-

fected. This morphological “simplification” is

thought to be a result of functional morphologi-

cal adaptation and evidently it has developed in-

dependently in several lineages. Although very

little is known so far of the functional morphol-

ogy of otoliths it has been observed empirically

that many benthic fishes have developed “look

alike” otoliths. Common characteristics are a ro-

bust, relatively large otolith, smooth otolith rims

and a smooth outer surface and, finally, a “sim-

plified” sulcus pattern. Typically, the sulcus open-

ing is reduced, its outline becomes smoother, ul-

timately forming a regular oval shape, and ostial

and caudal colliculi become fused. Often the sul-

cus becomes very shallow, level with the rest of

the inner face. This kind of sulcus is found in

6. Morphological characterisation of Pleuronectiformes otoliths

many pleuronectiforms but is also common in

other benthic fishes (for instance Congroidei, Lo-

phiiformes, Ophidiiformes, Gobioidei). There is,

however, a second morphotype of sulcus organ-

isation in benthic fishes that is characterised by a

deepened (though “simplified”) sulcus usually

combined with a well developed opening. Such

otoliths are found in the Pleuronectiformes as

well, although less commonly, and are also known

from such benthic fishes as the Anguilloidei,

Gobiesociformes, Cottoidei or Blennioidei.

From this discussion it is understandable why

pleuronectiform otoliths are not very easily char-

acterised and in the fossil record they have some-

times been confused with representatives of oth-

er, unrelated Teleosts. Sulcus morphology, usual-

ly the most diagnostically valid and most stable

character, in many instances does not allow the

differentiation of pleuronectiform otoliths from

those of certain other groups of benthic fishes.

Fortunately, there is one single character seem-

ingly unique to the Pleuronectiformes. This is the

circumsulcal depression. The circumsulcal de-

pression is usually deep and well marked, but

there are also instances where it can be relatively

feeble (particularly in otoliths from the blind side),

Piscium Catalogus, Part Otolithi piscium, Vol. 2

very narrow or disrupted behind the tip of the

cauda. In these cases proper assignment of isolat-

ed otoliths, fossil or recent, to the Pleuronecti-

formes can become a little more difficult, partic-

ularly if erosional effects are also involved.

In the following I briefly discuss the various

morphological characters that occur in the Pleuro-

nectiformes. For a few peculiar features informal

circumscriptive terms are used in order to short-

en repeated descriptions in the systematic part.

Outline. The outline of most pleuronectiform

otoliths is smooth, rounded, but rectangular and

other shapes occur as well. Sometimes it is irreg-

ularly lobate or undulate. Angles along the rims

are rare, the most common ones being an obtuse

medioventral angle particularly in the Psettodi-

dae (fig. 6), Scophthalmidae and certain Bothi-

dae (fig. 9). A postdorsal angle situated at the

very end of the dorsal rim is characteristic for

several pleuronectids and can be quite sharp (fig.

10). Otherwise pre- and postdorsal angles are

rarely observed and are usually very feeble. Cer-

tain Soleidae and Cynoglossidae have developed

some kind of predorsal lobe at the anterior end of

the dorsal rim. This predorsal lobe is also present

in Brachypleura and in fact has been developed

most strongly (fig. 11). In some Bothidae (Pseu-

dorhombus, Syacium and Citharichthys Groups) the

predorsal rim is expanded to some kind of broad

projection. The posterior tip of the otolith can be

developed quite diversely. Usually it is blunt or

rounded, but it can also be pointed. Pointed pos-

terior tips are known from the Psettodidae (fig. 6;

inframedian), some Citharidae, Bothidae (fig. 9)

and the pleuronectid genus Marleyella (median)

and Paralichthodes (supramedian). Concave pos-

terior rims occur in most Cynoglossidae and the

Solea and Pardachirus Groups of the Soleidae

(fig. 12). Anteriorly many pleuronectiform oto-

liths exhibit some kind of rostrum (fig. 6-11),

whereas development of an excisura (see sulcus

opening) and an antirostrum are much more sel-

dom (fig. 7-8).

The rostrum is usually massive, not pointed

and developed best in the more “primitive” mem-

bers of the order (fig. 6-9). Nevertheless, a ros-

trum look-alike and probably homologous pro-

jection is also evident from many otoliths with a

reduced sulcus opening (fig. 9-11). Development

of the rostrum and in some instances its length

are important characters of diagnostic value.

In certain very thin and delicately ornament-

ed otoliths one sometimes observes a tendency

to “skeletonization” of the outline of the otolith.

This means that radial marginal furrows trans-

form into deep incisions or “fenestrae”. This trend

usually occurs in otoliths of epipelagic fishes. In

the Pleuronectiformes this phenomenon is ob-

served best in the otoliths of the genus Reinhard-

tius. In otoliths of the blind side “skeletonization”

occurs postdorsally and in otoliths of the eyed

side preventrally. Similar effects, although to a

much lesser degree, have also been observed in

otoliths of the genera Psettodes and Rhombosolea.

Inner face. Circumsulcal depression (fig.5a): a

depression surrounding the sulcus dorsally and

ventrally and joined behind the caudal tip. The

circumsulcal depression has developed as a com-

bination of the dorsal depression known from

most Teleosts and a ventral depression which in

its expression is unique amongst Teleosts.

SCHWARZHANS (1995) has postulated that this

ventral depression has developed between the

area of the “classical” ventral line and a second

“doubled” ventral line closer to the sulcus as

observed in certain Percoidei. The circumsulcal

depression should not be confused with the con-

tinuous line (”extended” ventral line) as observed

in Gobioidei or the fusion of the ventral line with

the dorsal depression seen in certain Trachinoi-

dei. These lines are not homologous and run close

to the rim of the otolith. The circumsulcal depres-

sion is usually situated very close to the sulcus,

leaving only the cristae superior and inferior to

separate them. Usually, the separation of the cir-

cumsulcal depression is fairly sharp towards the

cristae and more gradual outwards towards the

otolith margins. An exception is seen in the Cy-

noglossidae and certain Soleidae which have a

(secondarily reduced) narrow circumsulcal de-

pression, sometimes almost reduced to a line,

running at some distance from the sulcus (fig. 13).

In the genus Symphurus (Cynoglossidae) the cir-

cumsulcal depression is bilobate with extended

areas postdorsally and postventrally. Width and

depth of the circumsulcal depression is quite

variable and in some instances can be of diagnos-

tic importance. The junction of the dorsal and

ventral depressions behind the caudal tip is usu-

ally somewhat shallowed. It is complete in most

Bothidae (fig. 9), Pleuronectidae (fig. 8, 10), Solei-

dae (fig. 12) and Cynoglossidae (fig. 13), but in-

complete (disrupted) in the more “primitive”

Pleuronectiformes (Psettodidae – fig. 6 -, Cithari-

Schwarzhans: Pleuronectiformes

Fig. 5: Morphological terminology in Pleuronectiform otoliths. Fig. 5a = Inner face; abbreviations: l = length,

h = height, s.i.a.=sulcus inclination angle. Figs. 5b, c = View from ventral; abbreviations: t = thickness, con.i. = con-

vexity of inner face, con.o. = convexity of outer face.

Figs. 6-13: Morphological examples of Pleuronectiform otoliths – fig. 6 genus Psettodes, fig. 7 genus Bothus, fig. 8

genus Samaris, fig. 9 genus Citharichthys, fig. 10 genus Hippoglosoides, fig. 11 genus Brachypleura, fig. 12genus Solea,

fig. 13 genus Cynoglossus (otoliths from the right-eyed flatfishes mirror-furned).

12 13

Piscium Catalogus, Part Otolithi piscium, Vol. 2

dae, Brachypleuridae – fig. 11 – , Scophthalmidae

and certain Bothidae – fig. 7).

Sulcus. Despite the tendency towards “simplifi-

cation” of the sulcus morphology observed in so

many Pleuronectiformes (see above) the sulcus

still remains the single most important character

for systematic purposes. However, in many in-

stances the correct interpretation of the outline of

the sulcus and the colliculi requires very careful

analysis. If the sulcus is very shallow, the outline

of the colliculi is usually well defined but the

outline of the sulcus may not be. If on the contra-

ry the sulcus is deep its outline is usually sharply

developed but the outline of the colliculi may not

be. Also the differentiation of the ostial and cau-

dal colliculi is often feeble where they meet or

approach each other.

Sulcus proportions (fig. 5a): Sulcus propor-

tions include sulcus versus whole otolith correla-

tions (otolith length to sulcus length; approach of

caudal tip to posterior tip of otolith; in the case of

an anteriorly closed sulcus approach of the ostial

tip to the anterior tip of the otolith). Intrasulcus

correlations are more important, in particularly

the length of the ostial colliculum to the length of

the caudal colliculum (ol:cl). In most pleuronec-

tiform otoliths the ostium is longer than the cau-

da, often by a factor of two or more. However, in

the more “primitive” members of the order (Pset-

todidae, Paralichthodes, Tephrinectes, Ammotretis

Group, Citharidae and some Achirinae) they are

of about equal length or the cauda is actually

longer than the ostium (fig. 6). It appears that

reduction of the cauda has developed at a faster

pace than reduction of the ostium. Within the

Soleidae, however, there is a single genus (Quense-

lia) in which, seemingly, the cauda has become

secondarily enlarged, approaching the length of

the ostium and, in the case of a fossil species,

(Quenselia cornuta), even surpassing it. This secon-

dary enlargement has probably occurred at the

expense of the ostial colliculum into which the

caudal colliculum appears to be protruding. Oth-

er intrasulcus correlations include ostium length

to height (ol:oh) and ostium height to cauda height

(oh:ch). However, any intrasulcus correlations can

of course only be applied where there is a clear

distinction between ostium and cauda, i.e. sepa-

ration of the colliculi. The latter is important since

the junction of ostium and cauda is not always

marked by an incursion or indentation at the

ventral rim of the sulcus.

Sulcus opening: A character of some diagnos-

tic value is the status of the sulcus opening. In

more “primitive” members of the Pleuronecti-

formes (Psettodidae, Tephrinectes, Paralichthodes,

Ammotretis Group, Citharidae, some Scophthalmi-

dae, Bothidae and the Microstomus-Pleuronichthys

and the Samaris Groups of the Pleuronectidae)

the ostium distinctly opens anteriorly and the

ostial colliculum meets the anterior rim of the

otolith (fig. 6-8). A definite ostial excisura is rare-

ly observed (Thysanopsetta, Chascanopsetta, Man-

copsetta and some members of the Bothus Group

of the Bothidae, Samaris Group – fig. 8 – of the

Pleuronectidae). More often one observes a cer-

tain reduction of the ostial opening. First it be-

comes indistinct (pseudoostial opening) with an

anteriorly closed ostial colliculum and finally the

ostium becomes completely closed anteriorly. The

latter has occurred separately in several distinct

lineages, for instance in the Brachypleuridae

(fig. 11), the Citharichthys (fig. 9) and Syacium

Groups of the Bothidae, the Isopsetta, Pleuronectes-

Limanda, Hippoglossoides (fig. 10) and Glyptoceph-

alus Groups of the Pleuronectidae, most Soleidae

(fig. 12) and Cynoglossidae (fig. 13). Sometimes

a faint ostial channel still connects the ostium

and the anterior rim of the otolith (fig. 11).

Sulcus outlines: Usually, the outline of the

sulcus in pleuronectiforms is not very spectacular.

Some exceptions, however, are described below.

Inclined caudal tip (fig. 6): A faintly inclining

caudal tip is only observed in what I regard as

the most “primitive” members of the Pleuronec-

tiformes (Psettodidae, Paralichthodes, Tephrinectes,

Ammotretis Group and incipiently in some Scoph-

thalmidae). This character is thought to be inher-

ited from some kind of perciform ancestor (see

also chapter 5.2).

Ventral expansion of collum (fig. 11): A small

widening of the sulcus just below the ostial-caudal

joint, which is deepened and remains unfilled by

colliculi. This character is only known from Bra-

chypleura (and incipiently so from Lepidoblepharon).

Bipartite ostium: In otoliths of the Synaptura

Group (Soleidae) the long ostium is divided into

two portions, marked by collum-like incursions

of the rims of the sulcus. The anterior portion of

the ostium is much narrower than the strongly

widened posterior portion and also deeper. In

some instances the bipartition of the ostium can

be more distinctly developed than the separation

of ostium and cauda.

Fusiform sulcus (fig. 9): A very “specialised”

Schwarzhans: Pleuronectiformes

sulcus outline is characterised by a widening of

the sulcus just behind its middle. The anterior

and posterior portions are much narrower, the

cauda terminating with a pointed tip. Ostial and

caudal colliculi are completely fused but it is

assumed that the conspicuous widening of the

sulcus corresponds with the posterior portion of

the ostium. The sulcus is shallow except for the

widened portion, which may be somewhat deep-

ened. The fusiform sulcus outline only occurs in

the Citharichthys and Syacium Groups and incipi-

ently also in the genus Tarphops of the Pseudor-

hombus Group (all Bothidae) and is accepted as a

synapomorphic character combining these fishes

phylogenetically.

Hammer-shaped cauda (fig. 13): In the Cy-

noglossidae and incipiently in a few Soleidae

(Pardachirus and Heteromycteris Groups) the cau-

da is extremely widened, both dorsally and ven-

trally, but very short. Its posterior termination is

abrupt, nearly vertically cut. Together with the

much narrower ostium the shape of the sulcus

resembles that of a hammer. In the Cynoglossi-

dae the colliculi are fused, but in the Soleidae

mentioned above (where this character is only

incipiently developed) ostial and caudal colliculi

are well separated. This feature, unique amongst

Teleostean otoliths, is a perfect autapomorphic

character found in all Cynoglossidae.

Deep sulcus (fig. 7-8): A continuously deep

sulcus is developed in the Ammotretis Group, the

Samaris and Microstomus-Pleuronichthys Groups

of the Pleuronectidae and part of the Achirus, the

Zebrias and part of the Synaptura Group of the

Soleidae. That of Samaris is probably the most

deeply incised sulcus observed in pleuronecti-

forms. More commonly, only ostial and caudal

colliculi are deepened. They may be connected

by a narrow furrow (Zeugopterus Group of Scoph-

thalmidae, certain members of the Bothus and

Arnoglossus Groups and the Thysanopsetta, Man-

copsetta and Chascanopsetta Groups of the Bothi-

dae) or completely separated, then looking like

two holes in the surface of the otolith (Hippoglos-

soides, Glyptocephalus and Poecilopsetta Groups of

the Pleuronectidae). Often the cauda is more

depressed than the ostium. Infact, in many so-

leids the cauda is depressed, whereas the ostium

has remained almost completely flat.

Sulcus orientation: In most Pleuronectiformes

the sulcus occupies a median position on the in-

ner face of the otolith, but supramedian and in-

framedian positions occasionally occur as well.

In some groups (particularly among the Bothi-

dae) the sulcus is not oriented horizontally on

the inner face but inclined downwards (fig. 5a).

The angle of inclination measured between the

long axis of the otolith and the axis of the sulcus

(s.i.a.) is in some instances an important tool for

differentiating between related species (for in-

stance of the genus Arnoglossus) or genera. Iden-

tification of the horizontal axis of the otolith is

not always easy. Rounded otoliths are displayed

such that the sulcus runs horizontally. Then, of

course, a sulcus inclination angle cannot be meas-

ured. Otoliths with anterior and posterior tips

are oriented along the axis connecting the two

points. Rectangular otoliths (for instance of the

Arnoglossus Group) are traditionally figured with

their ventral rims running horizontally. In these,

the sulcus inclination angle is often an important

feature.

Curvatures (fig. 5b-c). This is quite commonly

another diagnostically important group of fea-

tures. Curvatures, particularly of the inner face

both in horizontal (fig. 5b; con.i.) and in vertical

direction can often be used to distinguish the

otoliths of related genera which otherwise may

look quite similar. Also thickness of the otolith

and, to a lesser extent, curvatures of the outer

face (fig. 5c; con.o.) are useful characters. Also

smoothness of the inner face, depth and width of

the circumsulcal depression (as well as of the

sulcus) can thus be visualised much better. It is

therefore important to figure and describe lateral

views of pleuronectiform otoliths, preferably from

ventral and anterior aspects. – Outer faces on the

other hand do not exhibit much that is of diag-

nostic value and do not need to be figured in the

case of the Pleuronectiformes. Adequate figures

from lateral views are sufficient in this respect.

6.2 Side dimorphism

(Fig. 14-23)

Since pleuronectiform fishes as a group are char-

acterised by their extreme asymmetry similar

effects had to be expected from the otoliths.

KOKEN (1891), who laid the basis for sys-

tematic otolith research, was of the opinion that

pleuronectiform otoliths do not exhibit any kind

of clear cut asymmetry (apparently he looked at

only very few flatfish otoliths). His explanation

was that otoliths, situated in the “interior” of the

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Figs. 14-23: Examples of side dimorphism in Pleuronectiform otoliths – fig. 14 family Scophthalmidae,

figs. 15-18 family Bothidae, figs. 19-22 family Pleuronectidae, fig. 23 family Soleidae.

Lepidorhombus whiffiagonis

Trichopsetta ventralis

Chacanopsetta lugubris Mancopsetta milfordi

Paralichthys adspersus

Schwarzhans: Pleuronectiformes

Reinhardtius hippoglossoides

Parophrys vetulus

Rhombosolea tapirina

Glyptocephalus zachirus Dicologlossa cuneata

22 23

Piscium Catalogus, Part Otolithi piscium, Vol. 2

fish, may not react as vigorously to the forces of

functional adaptation as do organs along the

“periphery” of the fishes (for instance dentition).

We now know that his assumptions were wrong.

CHAINE & DUVERGIER, NOLF and

SCHWARZHANS have pointed out in several

publications that side dimorphism in the otoliths

of the Pleuronectiformes is just as characteristic

of the group. However, this phenomenon does

not occur in all flatfishes. There are a number of

species, genera and families which have relative-

ly symmetrical otoliths or else the asymmetry is

so slight that it is indistinguishable as a character,

within the normal range of intraspecific varia-

tion. Some genera include both species with and

without lateral dimorphism.

Of course, the phenomenon of asymmetrical

otoliths occasionally causes some problems when

identifying isolated otoliths particularly in fos-

sils. Although I know of only few instances where

left and right hand otoliths have been described

as different species (see entry to Laeops splendens

from the Miocene of Austria) paleontologists

describing fossil flatfish otoliths should be well

aware of the phenomenon. In principal diagnos-

tic differentiation of species should always be

based on comparison of otoliths from the same

side. New fossil species belonging to genera

which are known for their asymmetrical otolith

morphology should preferably be established if

and when otoliths of both sides are available.

With the extensive material now available it

is also possible to better understand the kinds

and variations of asymmetry that can occur. There

are a number of obvious regularities. First of all

it is, with very few exceptions, the otolith of the

eyed side that shows alterations from the “nor-

mal form”. Secondly, there are certain regular pat-

terns or kinds of asymmetrical development, a

fact which is helpful in the identification of iso-

lated otoliths. These regularities were a surpris-

ing discovery since practically every character can

be affected by asymmetry: – outline and propor-

tions of the otolith, depth and width of the sul-

cus, separation or fusion of colliculi, opening of

the ostium, development of an excisura, depth

and width of the circumsulcal depression, curva-

ture of the inner face. Also the degree of asym-

metrical development can vary considerably from

one genus to another (it is usually fairly consist-

ent within a given genus). In many instances the

alteration is not very strong and can readily be

recognised even in isolated otoliths. In other

words, even though left and right hand otoliths

may look different it is usually not very difficult

to tell which belong to the same species. This is

of great importance for the paleontologist who

has to deal with isolated otoliths. In close corre-

lation with the recent findings I was able to iden-

tify left and right hand otoliths in practically every

fossil species when they were both available. Even

in those instances of more strongly developed

asymmetry correlation with extant material usu-

ally solves the problem. In this respect it is inter-

esting to note that the otoliths of the

genus Rheinhardtius are amongst the ones with

the most strongly developed side dimorphism.

Paradoxically, this is the only pleuronectiform

known to swim in a vertical posture (except for

the “primitive” Psettodes).

Of the 120 genera of living and fossil Pleuronec-

tiformes of which otoliths have been studied 36

do not exhibit side dimorphism, corresponding

to a fourth of all genera known by otoliths. These

are representatives of the Psettodidae, Cithari-

dae, Scophthalmidae (all except Lepidorhombus),

Cynoglossidae and a number of genera from the

families Bothidae and Soleidae. 9 additional gen-

era of the Bothidae and Soleidae include species

with asymmetrical otoliths (although usually very

faintly so) and others with symmetrical ones.

From a further 19 pleuronectiform genera only

blind side otoliths are available and therefore their

status in respect to symmetry remains question-

able (most of these genera are from the Soleidae).

Asymmetry of otoliths is established in at least

62 genera (including the 9 genera with occasional

asymmetry), corresponding to about half of all

investigated genera. Otolith asymmetry is par-

ticularly widespread in the Pleuronectidae, but is

also known from several Bothidae and Soleidae.

However, once otoliths of both sides are described

from the 19 not investigated and the 19 single

sided genera this number is likely to increase

further. However, the effects of side dimorphism

in most of these cases are not very dramatic.

17 genera show alterations of a single character

only. Only 13 genera (about 10%) exhibit really

pronounced otolith asymmetry. They are Lepido-

blepharon (Brachypleuridae), Lepidorhombus

(Scophthalmidae, fig. 14), Chascanopsetta (Bothi-

dae, fig. 17), Eopsetta, Reinhardtius (fig. 20), Hip-

poglossoides, Lyopsetta, Glyptocephalus (fig. 22), Paro-

phrys, Hypsopsetta, Rhombosolea (Pleuronectidae,

fig. 21), Soleichthys and Dicologlossa (Soleidae, fig.

Schwarzhans: Pleuronectiformes

23). As stated above, alterations usually occur in

otoliths of the eyed side. Some exceptions to this

rule seem to be manifested in the genera Cyclopset-

ta, Chascanopsetta (Bothidae), Hypsopsetta and

Rhombosolea (Pleuronectidae).

The various types of side dimorphism observed

in pleuronectiform otoliths are described below.

Descriptions centre on the alterations from the

“normal” picture and usually refer to otoliths from

the eyed side. The table below lists all the genera

investigated and the various characters affected

by asymmetry for each genus. Unfortunately, left

and right hand otoliths are not known from eve-

ry genus and such cases are marked accordingly

on the list.

Outline and proportions of otoliths. The most

common type of asymmetry is observed in de-

tails of the outline of the otolith (45 genera). Usu-

ally, the outline of the altered otoliths (mostly

from the eyed side) appear to be smoother and

more uniform than those from the blind side (the

reverse in Chascanopsetta, Hypsopsetta and Rhom-

bosolea). The strongest type of alteration of the

outline of the otolith is observed in the genera

Chascanopsetta (fig. 17), Reinhardtius (fig. 20), Hip-

poglossoides, Hypsopsetta and Rhombosolea (fig. 21).

Sometimes alteration of the outline is also reflect-

ed in the proportions of the otolith (length to

height ratio; 5 genera). In this respect, otoliths of

the eyed side are usually more elongate than those

of the blind side.

Sulcus and colliculi. Quite commonly otoliths

from the eyed side slightly differ from those of

the blind side in certain aspects of the sulcus

morphology. Often, the sulcus is slightly narrow-

er, sometimes also shorter and in few instances

deeper. Also the proportions of ostium to cauda

may be affected. Another common character is a

reduced separation of the ostial and the caudal

colliculum. Sometimes these are completely fused

in otoliths of the eyed side whereas they are clearly

separated in otoliths of the blind side. The most

striking examples of this are found in the otoliths

of Reinhardtius and Glyptocephalus. Side dimor-

phism in the morphology of the sulcus and/or

colliculi is observed in 42 genera. The strongest

alterations occur in Lepidoblepharon, Lepidorhom-

bus (fig. 14), Reinhardtius (fig. 20), Hippoglossoides,

Lyopsetta, Glyptocephalus (fig.22), Dicologlossa

(fig. 23) and Soleichthys (in just one of two spe-

cies). The soleid Dicologlossa is remarkable for the

different sizes of its caudal colliculum which is

larger in otoliths of the eyed side than in otoliths

of the blind side.

Sulcus opening and excisura. These characters

are much less commonly affected by side dimor-

phism (11 genera). Where it occurs, otoliths of the

eyed side usually exhibit a more clear cut open-

ing of the ostium and a deeper excisura (the

reverse in Rhombosolea). Chascanopsetta (fig. 17)

and Rhombosolea (fig. 21) are the only genera in

which this character is strongly developed.

Circumsulcal depression and curvature of the

inner face. This is another set of characters in-

volved in side dimorphism. Often it is the most

noticeable affected feature where it has been sub-

ject to alteration. At a low level of alteration the

circumsulcal depression of the otolith from the

eyed side may just be somewhat narrower or

shallower than that of the blind side. Sometimes,

however, it almost disappears in otoliths from

the eyed side. In the more pronounced cases the

surface of the circumsulcal depression, particu-

larly its rear portion, is completely filled with

sharp radial furrows and ridges the latter often

exhibiting some kind of crystalline structure. At

first sight the inner face of the otolith looks as if

it has been eroded exposing the internal texture

of the otolith at the surface. There are, however,

few cases where this structure is developed in

otoliths of both sides. Another character often

combined with the reduction of the circumsulcal

depression is a change in the curvature of the

inner face, the inner face of otoliths from the eyed

side becoming more convex. These characters,

individually or in combination, are observed in

24 genera. Except for Rhombosolea they are only to

be found in otoliths from the eyed side. They are

most strongly developed in the genera Lepidorhom-

bus (fig. 14), Eopsetta, Hippoglossoides and Paro-

phrys (fig. 19).

Key to the table listing asymmetrical develop-

ment of otoliths:

An asterisk (*) denotes alterations in otoliths

of the blind side; a double-cross (#) on the eyed

side. One mark corresponds to moderate altera-

tion, two marks to strong alteration. A cross (+) is

used in columns referring to general informations.

Each character is coded by a number as fol-

lows.

Piscium Catalogus, Part Otolithi piscium, Vol. 2

?s.12345678

Caulopsetta #

Lophonectes +

Psettina ##

Taeniopsetta +

Trichopsetta ## #

Engyophrys ##

Laeops +##

Monolene ##

Asterorhombus +

Engyprosopon ###

Crossorhombus ##

Thysanopsetta #

Chascanopsetta ****####

Mancopsetta +##

Pleuronectidae

Eopsetta ## # ###

Hippoglossus ## # ##

Atherestes ##

Cleisthenes ##

Lyopsetta ### # #

Acanthopsetta +

Hippoglossoides ### ## #

Reinhardtius ## # ## ## * # #

Tanakius +

Glyptocephalus ### ##

Limanda #

Dexistes +

Liopsetta +

Parophrys ## # ####

Pleuronectes # # juv. #

Platichthys ## ##

Kareius ## #

Pseudopleuronectes ##

Lepidopsetta ##

Inopsetta #

Psettichthys +

Isopsetta ##

Verasper ## #

Clidoderma +

Microstomus #

Pleuronichthys #

Hypsopsetta #****

Pelotretis #####

Rhombosolea ******** *

Plagiopsetta ## ##

Samaris #

Samariscus ###

Azygopus +

Marleyella +

Poecilopsetta ###

Nematops

Soleidae

Trinectes +

Achirus +

Catathyridium +

Hypoclinemus +

Gymnachirus +

1 =sulcus shape and/or depth

2 =separation of colliculi

3 =otolith proportions (l:h)

4 =outline of the otolith

5 =sulcus opening

6 =excisura

7 =depth, width and expression of the circum-

sulcal depression

8 =curvature of the inner face

A question mark (?) indicates those cases,

where the status of asymmetry is unknown, i.e.

otolith is known from one side only. The abbrevi-

ation s. stands for symmetrical otoliths.

?s.12345678

Psettodidae

Psettodes +

genera of uncertain relationship

Tephrinectes +

Paralichthodes +

Collistium #

Ammotretis +

Oncopterus +

Citharidae

Citharus +

Paracitharus +

Citharoides +

†Rhombocitharus +

Brachypleuridae

Lepidoblepharon ## ## #

Brachypleura #

Scophthalmidae

Scophthalmus +

Lepidorhombus ## # # # ## ##

Zeugopterus +

Phrynorhombus *

Bothidae

Ancylopsetta +

Gastropsetta +

Hippoglossina ##

Xystreurys +

Lioglossina ##

Paralichthys +#

Pseudorhombus +##

Tarphops +

Syacium +

Cyclopsetta +*

Citharichthys +

Orthopsetta +

Etropus +

Bothus ##

Parabothus #

Grammatobothus +

Neolaeops +

Arnoglossus +

Schwarzhans: Pleuronectiformes

more, as the example of Pleuronectes platessa

shows, early ontogenetic side dimorphism may

differ in character from that of adults (chapter

6.3). – I have made similar observations with

otoliths of the genus Rhombosolea. There, quite

dramatic changes in the nature of the side dimor-

phism apparently occurs much later in the on-

togeny. Otoliths of 3 to 4 mm length usually ex-

hibit a rather distinct rostrum and often a clear

sulcus opening, both particularly in otoliths of

the blind side (side dimorphism). In otoliths of 5

mm of length and more rostrum and sulcus open-

ing are reduced or practically absent. Side dimor-

phism now finds its expression in differences in

the outline, otolith proportions, curvatures and

presence of an excisura on blind sided otoliths. In

fact, side dimorphism is quite strong in both

ontogenetic stages observed.

6.3 Variability and ontogenetic trends

The intraspecific variability in flatfish otoliths is

high; higher than in otoliths of most other Teleost

groups. A good impression of the range of this

variation may be gained from a number of pleu-

ronectiform species, both recent and fossil, fig-

ured by CHAINE (1936) and in this treatise. NOLF

(1985) noted that although the intraspecific var-

iability is unusually high in flatfishes the charac-

ters of individual species can still be recognised

if one has a good series of otoliths. SCHWARZ-

HANS (1984) remarked that particularly in the

Soleoidei, where the morphology of otoliths is

strongly reduced, there may exist cases where

otoliths of related species are not always distin-

guishable.

It now appears that the degree of intraspecif-

ic variability is quite different from one group of

flatfishes to another. For instance groups with a

relatively low degree of variability are the Psetto-

didae, Brachypleuridae, the Paralichthys, Pseudor-

hombus, Citharichthys and Syacium Groups of the

Bothidae, most Pleuronectidae except for the

Microstomus-Pleuronichthys Group, the Brachirus,

Zebrias, Synaptura and Pardachirus Groups of the

Soleidae and the Cynoglossus Group of the Cyno-

glossidae. Groups with a high degree of intraspe-

cific variability are the Citharidae, most Scoph-

thalmidae, the Bothus and Arnoglossus Groups of

the Bothidae, the Microstomus-Pleuronichthys

Group of the Pleuronectidae, the Solea and part

of the Heteromycteris Groups of the Soleidae and

?s.12345678

Nodogymnus +

Apionichthys +

Microchirus ##

Monochirus ## #

Quenselia +#

Dicologlossa ##

Solea #

Microbuglossus +

Vanstraelenia ##

Bathysolea +

Austroglossus +

Synaptura ##

Heterobuglossus +

Dexillichthys +

Brachirus #

Anisochirus +

Phyllichthys +

Aesopia +

†Granulithus +

Soleichthys +##

Pseudaesopia +

Zebrias +###

†Praearchirolithus +

Aseraggodes +

†Pseudopardachirolithus +

Pardachirus +

Heteromycteris +

Rendahlia #

Peltorhamphus +#

Cynoglossidae

Cynoglossus *

Symphurus +

Some good examples of side dimorphism in oto-

liths are shown in figs. 14-23. More detailed re-

marks and figures are found in the descriptive

section, when and where side dimorphism has

been investigated.

It is not yet known in which ontogenetic stage

side dimorphism of otoliths may begin to devel-

op. However, one would expect it to occur earli-

est in postlarval stages when the fish settles on

the bottom and the other asymmetrical charac-

ters are being developed. Otoliths of pelagic lar-

val stages with which to examine this hypothesis

are, however, unknown.

I have investigated otoliths of early postlar-

val fishes from Pleuronectes platessa (TL=

27-60 mm). They do already show some kind of

incipient side dimorphism (see chapter 6.3). Re-

alising that the patterns of side dimorphism of

otoliths are quite different in many of the flatfish

genera it seems also likely that it may begin to

develop at different ontogenetic stages. Further-

Piscium Catalogus, Part Otolithi piscium, Vol. 2

part of the genus Symphurus of the Cynoglossi-

dae. In particular otoliths of the species-rich gen-

era Bothus, Arnoglossus, Engyprosopon, Laeops,

Monolene (Bothidae), Microchirus, Solea (Soleidae)

and Symphurus (Cynoglossidae) are at times very

difficult to differentiate accurately to species lev-

el. Also defining features for a reliable differenti-

ation of related genera sometimes presents some

difficulties and then remains very tentative. In

the fossil record of these genera we must be pre-

pared to deal with “morphological species

groups” rather than with defined species, at least

in some cases (see for instances entries to Microchi-

rus frequens, Microchirus kirchbergeanus or Symphu-

rus atricaudus). Other species-rich genera with a

much lower degree of intraspecific variability and

a better morphological differentiation do allow

for a relatively well established taxonomic ana-

lysis, for instance Paralichthys, Pseudorhombus,

Citharichthys (Bothidae) or Cynoglossus (Cynoglos-

sidae).

The characters most commonly affected by

intraspecific variability are those of the outline of

the otolith and its proportions. This is particular-

ly true for otoliths with a much reduced mor-

phology. Unfortunately, these characters are of-

ten important for distinguishing between closely

related species. It is advisable for the paleonto-

logist wishing to identify fossil pleuronectiform

otoliths to proceed very carefully in those cases

(see list of genera above) and adopt a “conserv-

ative” interpretation habit (see also chapter 4.1). –

Other characters such as details of the sulcus

morphology, thickness or curvatures may vary

as well, but usually to a much lesser degree.

Ontogenetic changes, as in almost any other Tel-

eost group, play a very important role in the Pleu-

ronectiformes and these are often of greater mag-

nitude than the differences due to intraspecific

variability. Otoliths of pelagic larval stages are

unknown. However, I have investigated otoliths

from early bottom-living postlarval stages of Pleu-

ronectes platessa and Samariscus triocellatus. Those

of Pleuronectes platessa came from fishes of 27 to

60 mm TL which were probably between 4 and 8

months old. Otolith sizes are 1.0 to 1.6 mm. They

differ from adults in many aspects of the outline,

but already show the typical pleuronectiform cir-

cumsulcal depression. Also the sulcus opening is

already much reduced. They even exhibit a very

faint side dimorphism as far as the development

of the posterior tip of the otolith is concerned (see

chapter 6.2), which is obscured and replaced by

other asymmetrical characters in adults. A simi-

lar observation occurring somewhat later in on-

togeny is observed in Rhombosolea tapirina and R.

plebeia. Left hand otoliths in the category up to

5 mm show a pronounced rostrum which is ab-

sent in right hand otoliths of the same size. In

larger specimens from 5 mm or greater, the ros-

trum is reduced in otoliths of both sides. Instead

left hand otoliths have developed some kind of

irregular excisura. This indicates that side dimor-

phism, at least in some cases, may develop very

early in ontogeny and then it may be subject to

radical change as a process of subsequent devel-

opment.

In general, most juvenile otoliths exhibit a

much more generalised morphology than do

adults and in many cases (e.g. if found isolated)

these can only be identified in the context of a

well established ontogenetic succession. Charac-

ters affected are mostly those concerning features

of the outline of the otolith and its proportions,

curvature of the inner face and thickness. But also

certain aspects of the sulcus characters may at

times show allometric ontogenetic growth.

In the case of mixed lots of closely related

species, their respective juvenile representatives

may not be distinguishable at all (see for instance

entries to Arnoglossus novus and A. longus). At-

tempts to identify juvenile pleuronectiform oto-

liths should therefore be restricted to those cases

from which sufficient ontogenetic successions are

known.

In palaeontology the creation of doubtful flat-

fish records on the basis of juvenile otoliths has

become a problem. It is imperative that new fos-

sil species or new records (both geographic or

stratigraphic) are based on adult specimens which

have reached a certain minimum size that guar-

antees that valid diagnostic characters have been

developed. Since flatfishes and their correspond-

ing otoliths grow to quite different sizes it is nec-

essary to define such minimum sizes separately

for each genus or genus group. For example, an

adult otolith of the genus Hippoglossus may reach

10 to 15 mm in length, an adult Arnoglossus oto-

lith ranges from 2 to 4 mm, and an adult Apion-

ichthys otolith may be just slightly over 1 mm.

Wherever available data have permitted the def-

inition of minimum diagnostic size I have done

so in the following systematic part.

Usually, otoliths of the Pleuronectiformes are

fairly large when compared to the size of the fish,

Schwarzhans: Pleuronectiformes

with one notable exception: that of the Ammo-

tretis Group, which have comparatively small

otoliths.

6.4 Otoliths of reversed specimens

(Fig. 24-26)

In the great majority of flatfishes all the individ-

uals of a particular species and genus are either

right-sided (dextral) or left-sided (sinistral).

NORMAN (1934) has used this character as one

of the key parameters to define several families,

such as the Bothidae (sinistral eyes), Pleuronecti-

dae (dextral eyes), Soleidae (dextral eyes) and

Cynoglossidae (sinistral eyes) (see also chapter

5.3.2). Some of the more primitive members –

Psettodidae, Tephrinectes, Hippoglossina – are in-

differently dextral or sinistral. These are also

groups that do not exhibit side dimorphism in

otoliths.

However, reversal, or the occurrence of indi-

viduals with the eyes and colouring on the side

which is generally eyeless and unpigmented in

the species, is a not uncommon phenomenon in

certain other flatfishes as well, including some

species showing pronounced side dimorphism

in otoliths. One of the genera known for common

occurrence of reversed specimens is Platichthys.

Platichthys stellatus in particular is known for al-

most invariably reversed (sinistral) specimens in

the waters around Japan, whereas in California

the number of dextral and sinistral individuals is

about equal (NORMAN, 1934). Otoliths of the

two species of Platichthys (P. flesus and P. stellatus)

and a specimen from Rhombosolea tapirina from

the BMNH collection were selected to investigate

the influence that reversal might have on the

morphology of their otoliths already known for

pronounced side dimorphism.

In these specimens it was found that reversal

of the fish does not mean that the features of the

otolith morphology affected by side dimorphism

become simply reversed as well. In other words,

the otolith of the right (blind) side of a reversed

individual from a sinistral specimen does not

necessarily resemble the otolith of the left (blind)

side of a non-reversed individual from a dextral

specimen (and neither do the otoliths of the re-

spective eyed sides).

In Platichthys stellatus (fig. 24), however, one

character is indeed developed in mirror image,

and this is the reduced separation of the colliculi

in otoliths of the eyed side (right side in normal

specimens and left side in reversed individuals).

With that exception side dimorphism does not

become transformed. In fact in otoliths of reversed

individuals the typical side dimorphic features

characteristic of the non-reversed individuals

become less pronounced and both sides come to

resemble each other more closely. More intrigu-

ingly, otoliths of reversed specimens exhibit a

different habitus than those of non-reversed in-

dividuals. Reversed specimens from California

show much more elongate otoliths than non-re-

versed, whereas reversed specimens from the

West Pacific show more compressed otoliths than

non-reversed ones. Clearly, when investigated as

isolated otoliths (for instance in the fossil record)

these three morphotypes would have been at-

tributed to three different species.

In Platichthys flesus (fig. 25), reversal has a less

pronounced effect on otolith morphology. Oto-

liths of reversed specimens have practically lost

all the side dimorphic features (including the lack

of separation of the colliculi, see above) and are

almost completely symmetrical (resembling oto-

liths of the blind, left side of non-reversed indi-

viduals). Apart from that they do not differ much

from those of non-reversed specimens.

The single reversed specimen of Rhombosolea

tapirina (fig. 26) investigated shows otoliths which

are much more compressed than those of non-

reversed individuals. Also the morphology of the

sulcus is somewhat distorted. The typical side

dimorphic features observed in non-reversed

specimens are lacking. As with Platichthys stella-

tus the otoliths of the reversed specimen would

probably be attributed to a separate species if

analysed in isolation.

It can be concluded from these investigations

that reversal has quite different effects on otolith

morphology from one species to another, is un-

predictable in morphological terms and needs to

be investigated separately for each species. From

the otolith morphology alone it can not be judged

whether a given otolith has originated from a

non-reversed “normal” individual or a reversed

one. For the paleontologist dealing with isolated

otoliths it means once again that he or she should

deal very carefully with unique aberrant speci-

mens of genera known for side dimorphism in

otoliths (practically all Pleuronectidae and many

Bothidae). They could represent “distorted” oto-

liths of a reversed specimen (or else teratological

effects). It will, however, become difficult in those

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Platichthys stellatus

dextral (normal) from California

sinistral (reversed) from California

sinistral (reversed) from NW-Pacific

Schwarzhans: Pleuronectiformes

very few instances, where reversal occurs regu-

larly in side dimorphic otoliths as, for example,

in the recent Platichthys stellatus. Although this

phenomenon appears to occur extremely rarely

(at least in recent flatfishes) it must still be born

in mind that clearly distinct flatfish otolith mor-

phologies do not necessarily represent different

species in every case.

6.5 Sexual dimorphism

The differences between the sexes in certain gen-

era and species is most marked in the overall

external morphology, especially in the family

Bothidae and certain Pleuronectidae. Various

characters may be involved such as scales, rostral

and orbital spines, interorbital width, form of fins,

Figs. 24-26: Examples of otolith morphology in reversed and normal specimens of Pleuronectiform fishes –

fig. 24 Platichthys stellatus, fig. 25 Platichthys flesus, fig. 26 Rhombosolea tapirina.

Rhombosolea tapirina

dextral (normal)

sinistral (reversed)

25dextral (normal) sinistral (reversed)

Platichthys flesus

Piscium Catalogus, Part Otolithi piscium, Vol. 2

coloration, and (in Marleyella bicolorata) the teeth

(NORMAN, 1934). In some instances sexual di-

morphism is such that males and females of a

single species were originally described as sepa-

rate species (see entry for Syacium ovale).

In otoliths, sexual dimorphism has been ob-

served only very rarely (SCHWARZHANS 1994).

In the case of the Pleuronectiformes I have

checked several species with external sexual dif-

ferences (Bothidae, Marleyella) for corresponding

sexual dimorphism in the otoliths. Marleyella,

which was noted by NORMAN (1934) as a flat-

fish with a very peculiar type of sexual dimor-

phism, did not show any sexual differences in

their otoliths. The same is true for practically all

Bothidae investigated in this respect. A possible

exception is Syacium ovale. In that species, it seems

that otoliths from females differ from those of

males in having less ornamented rims and a pro-

nounced postdorsal concavity. This, however, is

only true for otoliths of the blind side (right side);

those of the eyed (left) side can not be distin-

guished. In this respect it is interesting to note

that Syacium ovale is one of the bothid species

with strongly enlarged interorbital width in males.

Other genera with such a sexually dimorphic

development of the interorbital width, chiefly of

the Bothus and Engyprosopon Groups, either could

not be checked for otoliths or gave inconclusive

results. Nevertheless, I think it is quite possible

that sexually dimorphic interorbital widths may

express themselves in sexually dimorphic oto-

liths as well. This subject needs further investiga-

tion.

Otoliths of the species of the Samaris Group

often exhibit two quite distinct morphologies. One

morphology is characterised by a more com-

pressed appearance, a clear excisura and rostrum

and strongly ornamented rims, whereas the oth-

er morphology is more elongate, with a reduced

excisura, rounded rostrum and a more regularly

curving and smooth outline. This phenomenon

is observed in Plagiopsetta and Samaris (see re-

spective entries), and may also be expected in the

third genus of the group – Samariscus. None of

these genera is known for external sexual differ-

ences. Nevertheless, I suspect that the two mor-

phologies observed in otoliths possibly might rep-

resent such sexual dimorphism. (In the few in-

stances of known sexual dimorphism of otoliths

sexual differences of external characters likewise

are usually inconspicuous; see SCHWARZHANS

1994.) Unfortunately, I was not able to verify this

hypothesis by identifying the sexes of the speci-

mens involved. The fishes of Samaris from which

the otoliths have been taken (coll. IRSNB) could

not be traced and the specimens of Plagiopsetta

could not be identified to sex.

Schwarzhans: Pleuronectiformes

Abbreviations used:

l:h = otolith length to otolith height

h:t = otolith height to otolith thickness

ol:cl = ostium length to cauda length

oh:ch = ostium height to cauda height

s.i.a. = sulcus inclination angle

con.i. = convexity index of inner face (otolith

length/2 to thickness of inner face in

ventral view)

con.o. = convexity index of outer face (otolith

length/2 to thickness of outer face in

ventral view)

Synonymy listings for recent fishes only include

primary synonyms and are mostly based on

NORMAN (1934) for Pleuronectoidei and ME-

NON (1978) for Cynoglossus. Other references

(Soleoidei) are based on various sources and list-

ings may not be complete. Synonymy listings for

fossil otolith based species are as complete as

possible. However, secondary references are only

included if either checked with original speci-

mens or if figures in literature are detailed enough

to allow identification. Thus a number of ques-

tionable or not verified secondary references are

omitted for the time being.

7.1 Psettodidae

Genera: The family Psettodidae contains but a

single recent genus – Psettodes – with two recent

species, one from tropical West Africa, the other

from East Africa and the Red Sea to the western

Pacific. Two fossil otolith based species have been

recorded from the Eocene of Belgium and France.

Joleaudichthys CHABANAUD 1937, a fossil skel-

eton based genus from the Middle Eocene of

Egypt, may also be placed in the Psettodidae

(HUBBS 1945).

Definition and relationship: NORMAN (1934)

has worked out in great detail the very “primi-

tive” nature of the genus Psettodes. Plesiomorphic

characters include the high degree of symmetry

(pelvic fins, nasal organ, lateral line, dentition),

the indifference in left and right eyed individu-

als, the low number of anal (<45) and dorsal (<60)

fin rays, the presence of a spine in the dorsal and

pelvic fins, the tip of the dorsal fin situated be-

hind the nostrils, and the dimorphic optic chias-

ma. Psettodes frequently swims in an upright

posture . The only autapomorphic character that

NORMAN was able to identify is the absence of

gill rakers.

Otoliths likewise are characterized by a num-

ber of plesiomorphic features, such as the dis-

tinct anterior opening of the sulcus, the long and

narrow cauda with its slightly inclined caudal

tip, and the incomplete circumsulcal depression

(see also chapter 5.2).

Discussion: As suggested on various occasions

(see chapter 5.2) Psettodid otoliths strongly re-

semble certain percoid otolith patterns. Otolith

analysis supports NORMAN’s concept of the very

plesiomorphic nature of the Psettodidae with

respect to the other pleuronectiforms and their

origin from a percoid stock. Psettodidae repre-

sent the earliest fossil records of the flatfishes (to-

gether with a few other primitive genera) dating

back, at least, to Early Eocene times. Otolith mor-

phology has not changed much since then.

Psettodes BENNETT 1831

Type-species: Psettodes belcheri BENNETT 1831

syn. Sphagomorus COPE 1869 (type-species: Pleu-

ronectes erumei)

Diagnosis: Thin, elongate otoliths; ventral rim

gently curving, dorsal rim with distinct pre- and

postdorsal angles, posterior tip pointed, angular;

index l:h 1.6 to 2.6.

Ostium widened, anteriorly open, shallow,

shorter than cauda. Cauda long, narrow, some-

what deepened, with pointed and slightly inclined

posterior tip. Index ol:cl < 1.0. Dorsal and ventral

depression not connected around caudal tip, not

forming a circumsulcal depression. Ventral de-

pression rather short.

Inner face slightly convex; outer face slightly

concave, with some radial ornamentation. Rims

sharp, thin, often crenulated (particularly the

ventral rim).

7. Descriptive Part

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Measurements:

l:h h:t ol:cl oh:ch con.i

belcheri (ad.) 2.15-2.60 >3.5 0.75-0.95 1.8-2.2 about 6

belcheri (juv.) 1.80-2.00 >3.5 0.95 1.9 about 6

erumei (ad.) 2.00-2.15 >3.5 0.90 1.8 about 6

erumei (juv.) 1.65-1.85 >3.5 0.75-0.95 2.0-2.6 about 5

† collatus 1.65-1.75 3.5 0.85-1.05 1.9-2.2 about 4

† bavayi 1.80 3.0 0.70 1.6 about 6

Side dimorphism: Not apparent.

Variability and ontogeny: CHAINE (1936) has

figured a large series of otoliths of the two recent

species. From his illustrations it appears that the

variability in this genus is relatively moderate,

restricted to slight variations in outline and oto-

lith proportions. Ontogenetic changes are much

stronger as shown in the figures to both recent

species. Smaller otoliths as a rule are considera-

bly more compressed than larger otoliths. The

smallest specimen figured is about 5 mm long. It

already exhibits good diagnostic characters, but

only otoliths from 6 to 7 mm onward seem to

have developed the full set of pertinent diagnos-

tic features. Otoliths from truly adult fishes are in

the range of 10 to 15 mm.

Species and distribution: Two recent species:

P. belcheri from the tropical west African coast and

P. erumei ranging from East Africa to the tropical

western Pacific. Two fossil species: P. collatus and

genus aff. Psettodes bavayi from the Lower Eocene

of the Aquitaine Basin (France) which is tenta-

tively placed in this genus. The latter is even more

plesiomorphic in several characters and may very

well represent an extinct fossil genus. In addition

STEURBAUT (1984) has recorded a Psettodes sp.

from the Lower Miocene of France (Aquitaine

Basin).

Psettodes belcheri BENNETT 1831

Figs. 27-29

syn. Psettodes bennettii STEINDACHNER 1870

Investigated otoliths: 3 otoliths, one (left side,

fig. 27) IRSNB (coll. Nolf), one (right side, fig. 28)

from off Lagos, Nigeria, BMNH 1914.11.2.73, one

(left side, fig. 29) from off Accra, Gold Coast,

BMNH 1930.3.24.43.

Discussion: Otoliths of P. belcheri are always

more elongate than those of P. erumei of the same

ontogenetic stage. Also the ostium is usually nar-

rower and the marginal crenulation more irregu-

larly developed. Illustrations in CHAINE (1936)

exhibit a notable trend to develop “fenestrate”

otolith margins.

Distribution: Tropical West Africa, at shallow

depth.

Psettodes erumei (SCHNEIDER 1801)

Figs. 30-31

syn. Pleuronectes nalaka CUVIER 1829

syn. Hippoglossus dentex RICHARDSON 1845

syn. Hippoglossus orthorhynchus RICHARDSON

1846

syn. Hippoglossus goniographicus RICHARDSON

1846

Investigated otoliths: Three otoliths, one (right

side, fig. 30) from Western Australia, ZMH Ot.

1.12.1993.1 (coll. Schwarzhans, leg. WAM), one

(left side, fig. 31) from off Orissa, India, BMNH

1927.1.6.1, one (left side) from the Persian Gulf

off Saudi Arabia, BMNH 1987.2.12.29.

Discussion: Otoliths of P. erumei are more com-

pressed than those of P. belcheri of the same size

and more regularly ornamented. The ventral rim

is more deeply curving, often with an obtuse

midventral angle.

Distribution: Red Sea and Indo-West-Pacific

from South Africa to Australia and Japan, in shal-

low water.

Psettodes collatus NOLF 1972

Figs. 32-39

syn. Psettodes collatus NOLF 1972 – NOLF 1972a:

fig. 25

syn. Psettodes oedelemensis NOLF 1972 – NOLF

1972b: pl. 3, fig. 5-6

syn. Psettodes oedelemensis – NOLF 1972c: pl. 2,

fig. 24

syn. Psettodes spinosus NOLF 1972 – NOLF 1972c:

pl. 2, fig. 25

syn. Psettodes

sp. – NOLF 1988: pl. 14, fig. 2

Investigated otoliths: 8 otoliths, the holotype of

P. collatus (fig. 32; IRSNB P 2221) from the Ledian

Schwarzhans: Pleuronectiformes

(Middle Eocene) of Balegem (Belgium), a para-

type of P. collatus (fig. 37; IRSNB P) from the

Middle Eocene of Meldert (Belgium), two further

specimens from Balegem (figs. 33-34; IRSNB

P 2163-2164), the holotype of P. oedelemensis

(fig. 39; IRSNB P 2261) from the Sands of Oedelem

(Middle Eocene) of Oedelem (Belgium) and the

paratype of P. oedelemensis (fig. 38; IRSNB P 2262)

from the Calcier Grossier (Middle Eocene) of

Fercourt (France), the holotype of P. spinosus

(fig. 35; IRSNB P 2314) from the Calcier Grossier

(Middle Eocene) of Fercourt (Paris Basin, France)

and the specimen described as P. sp. by NOLF

(1988) (fig. 36; IRSNB P 4518) from the Ypresian

(Lower Eocene) of the tuilerie de Gan (Aquitaine

Basin, France).

Ontogeny and variability: The specimens inves-

tigated are between 2.5 and 5.5 mm in size. The

smaller specimens (figs. 32-36) are somewhat

more generalized in outline as the larger ones

(figs. 37-39) and show more delicately ornament-

ed rims. The largest specimens, including a para-

type of P. collatus (fig. 37) and the holotype and

paratype of P. oedelemensis (figs. 38-39) show a

tendency to reduce the intensity of the marginal

crenulation and develop a more accentuated

postdorsal angle.

Variations in morphology are restricted to

relatively few characters. These are the strength

of the marginal crenulation and development of

the postdorsal angle, which usually is quite

rounded, and the strength of the caudal curva-

ture.

Discussion: The holotype of P. collatus is of mod-

erate size and perfectly preserved. It is a typical

specimen of the genus Psettodes, quite similar to

the recent P. erumei. The main difference to the

recent species is the more rounded postdorsal

angle and the blunt posterior tip.

Figs. 27-29: Psettodes belcheri BENNETT 1831 – 6 ×

Figs. 30-31: Psettodes erumei (SCHNEIDER 1801) – 6 ×

27b

27a

30a

30b

31a

31b

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Similar otoliths have been described by NOLF

from the Middle Eocene of Belgium and France as

P. oedelemensis and P. spinosus. The latter is based

on a unique and very small type-specimen which

I find to fit perfectly with specimens of P. collatus

of the same size. This specimen and also the one

described by NOLF (1988) in open specific no-

menclature from the Lower Eocene of the Aqui-

taine Basin therefore are synonymized with

P. collatus. P. oedelemensis is based on two much

larger specimens (5.5 mm), which both show a

pronounced postdorsal angle and a much lesser

degree of marginal crenulation. However, both

characters are likely to be the result of allometric

ontogenetic changes, similarly to the specimens

of the two recent species as figured by CHAINE

(1936). Furthermore, the holotype of P. oedelemen-

sis is slightly eroded marginally, which no doubt

has influenced the marginal ornamentation. The

large paratype of P. collatus from Meldert is the

only specimen of this nominal species in compa-

rable size. It too is somewhat eroded marginally

resulting in a similar intensity of the ornamenta-

tion as seen in the holotype of P. oedelemensis. The

only difference is the weaker postdorsal angle,

but this too could be an erosional effect. In the

light of allometric ontogenetical changes this sin-

gular character does not warrant the separation

of two species of the genus Psettodes occurring

simultaneously in stratigraphy and geography.

As it stands now, I have little doubts that P. spino-

sus, P. collatus and P. oedelemensis simply repre-

sent different ontogenetic stages of a single spe-

cies. P. collatus deserves priority over P. oedelemen-

sis and P. spinosus as the first species that has been

described by NOLF in a series of three subse-

quent publications in the same year, all dealing

with Eocene otoliths from Belgium and France.

Distribution: Lower Eocene of the Aquitaine

Basin (France) and Middle Eocene of Belgium and

the Paris Basin (France).

Figs. 32-36: Psettodes collatus NOLF 1972 – 15 ×

32a

32b

35b

35a

Schwarzhans: Pleuronectiformes

genus aff. Psettodes bavayi NOLF 1988

Figs. 40-41

syn. Psettodes bavayi NOLF 1988 – NOLF 1988:

pl. 14, fig. 1

Investigated otoliths: 2 otoliths, the holotype

(fig. 40, IRSNB P 4517) and the paratype (fig. 41,

IRSNB P) both from the Ypresian (Lower Eocene)

of tuillerie de Gan (Aquitaine Basin, France).

Ontogeny and variability: The paratype is about

half the size of the holotype and differs in show-

ing a less pronounced postdorsal angle and a

delicately crenulated rim.

Discussion: This species is known only from two

relatively small otoliths. The holotype is about

Figs. 37-39: Psettodes collatus NOLF 1972 – 15 ×

38a

38b

Piscium Catalogus, Part Otolithi piscium, Vol. 2

3.3 mm in size, the paratype 2.0 mm. Neverthe-

less, g. aff. P. bavayi is easily recognized by the

following characters – the elongate shape, the

pronounced postdorsal angle in combination with

the vertically cut posterior rim, the narrow os-

tium and the rather strongly bent cauda. Without

the ventral depression being present, these oto-

liths perfectly resemble certain Percoidei. In fact,

g. aff. P. bavayi represents the most plesiomor-

phic otolith pattern so far observed in Pleuronec-

tiformes. In my opinion it probably represents an

extinct and very basal Pleuronectiform genus.

Closest resemblance no doubt is to Psettodes

(where this species is now preliminarily being

placed) and also Paralichthodes. The latter is sur-

prisingly similar in outline, the narrow ostium

and the very feeble ventral depression. Main dif-

ference is the deepened and widened caudal tip

in the recent otoliths of Paralichthodes algoensis.

Distribution: Lower Eocene of the Aquitaine

Basin (France).

7.2 Genera of uncertain relationship

Remarks: In this category I have provisionally

put together a few genera with very plesiomor-

phic otolith patterns, which in the past have been

placed in the Bothidae or Pleuronectidae respec-

tively. They are: Tephrinectes from Bothidae, Para-

lichthodes from Pleuronectidae (subfamily Para-

lichthodinae of NORMAN 1934), Colistium,

Ammotretis, Oncopterus and possibly also Psam-

modiscus and Taratretis from Pleuronectidae (sub-

family Rhombosoleinae of NORMAN 1934). Their

otoliths resemble those of psettodids and cith-

arids, and otolith-only studies would suggest

alternative classification. However, since charac-

ter analysis of the otoliths is based on plesiomor-

phic features alone I have selected to present them

in open familial nomenclature. Additional ich-

thyological analyses (f.i. osteological) will be

needed before an adequate taxonomic allocation

of these problematic genera can be formulated.

However, recently HENSLEY & AHLSTROM

(1984) have suggested a similar position regard-

ing the genus Tephrinectes.

As far as otolith analysis is concerned, it is

suspected that the phylogenetic divergence of

these genera occurred before the origin of the

Bothidae or Pleuronectidae in which they have

traditionally been placed. Some characters such

as the long and slightly inclined cauda and the

very incomplete circumsulcal depression are more

primitive than the pattern found in the Citharidae,

which may be regarded as the plesiomorphic sis-

ter-group of Scophthalmidae, Bothidae and Pleu-

ronectidae (see also entry for Citharidae).

The genera placed in this category of open

familial nomenclature fall readily into three ge-

nus groups - the Tephrinectes Group, the Paralich-

thodes Group (both monogeneric) and the Ammo-

tretis Group (for definitions see respective entries).

This grouping is different from that proposed by

NORMAN, and suggests also that these genera

are not in fact closely related. Their otoliths share

plesiomorphic features.

7.2.1 Tephrinectes Group

Genera: One genus – Tephrinectes – with one re-

cent species from the coasts of China.

Definition and relationship: Otoliths of Tephri-

nectes are very similar to those of Psettodes. How-

ever, this similarity is based on plesiomorphic

characters such as the clear anterior opening of

the sulcus, the long an narrow cauda with its

slightly inclined tip and the incomplete circum-

sulcal depression. The only difference of any

Figs. 40-41: Psettodes bavayi NOLF 1988 – 15 ×

40a

40b

Schwarzhans: Pleuronectiformes

importance is the index: ostium length to cauda

length (ol:cl) which is 1 or slightly more. Clearly

this is one of the most plesiomorphic otolith pat-

terns to be found in pleuronectiforms next to the

Psettodidae.

According to NORMAN’s detailed descrip-

tion the fish itself exhibits a number of primitive

characters as well. These are the indifference of

left and right eyed individuals, the low number

of anal (<40) and dorsal fin rays (<50), the tip of

the dorsal fin situated behind the nostrils, and

the olfactory laminae with a long rachis. These

are all plesiomorphic characters which Tephrinectes

shares with Psettodes. More advanced, in com-

parison with Psettodes, is the monomorphic optic

chiasma, the asymmetrical nature of the nasal

organ, and the loss of spines in the dorsal and

anal fins.

NORMAN (1934) placed Tephrinectes in the

family Bothidae, but judging by its position as

the first genus listed in the family Bothidae, he

probably regarded it as a primitive genus. Otolith

analysis suggests even a pre-bothid origin of the

genus. This agrees with the suggestion put for-

ward by HENSLEY & AHLSTROM (1984). In a

cladogram it may be placed close to the Cith-

aridae or between Psettodidae and Citharidae.

Tephrinectes GÜNTHER 1862

Type-species: Pleuronectes sinensis LACEPEDE

1802

syn. Tephrites GÜNTHER 1862 (preocc.; type-spe-

cies: Pleuronectes sinensis)

syn. Velifracta JORDAN 1907 (type-species: Pleu-

ronectes sinensis)

Diagnosis: Thin, moderately elongate otoliths;

ventral and dorsal rims gently curving, posterior

tip blunt, anterior tip with rostrum somewhat

more pointed; index l:h 1.65 to 1.8.

Ostium somewhat widened, anteriorly open,

shallow, about as long as cauda. Cauda narrow,

somewhat deepened, with pointed and slightly

inclined posterior tip. Index ol:cl 1.0 to 1.3. Dor-

sal and ventral depression not connected around

caudal tip, not forming a circumsulcal depres-

sion. Ventral depression feeble.

Inner face moderately convex; outer face

slightly concave, with some radial ornamenta-

tion. Rims sharp, thin, crenulated.

Measurements:

l:h h:t ol:cl oh:ch con.i

sinensis 1.65-1.80 about 4 1.0-1.3 1.5-2.0 about 4

Side dimorphism: Not apparent.

Species and distribution: A single living spe-

cies: T. sinensis from the coasts of China.

Tephrinectes sinensis (LACEPEDE 1802)

Figs. 42-45

Investigated otoliths: 4 otoliths, one (left side,

fig. 42) from Hongkong, BMNH 1939.3.23.90, one

(right side, fig. 43) from China, BMNH 65.5.2.29,

two (left and right side, figs. 44-45) from Fokien,

China, ZMH 20003.

Ontogeny and variability: The largest otolith

available is 6 mm long (fig. 42). Smaller otoliths

of about 2.5 mm length (figs. 44-45) are much more

intensely and irregularly crenulated along the

rims. They are still identifiable, but I would as-

sume that only otoliths larger than 4 mm (fig. 43)

have developed all pertinent diagnostic charac-

ters.

Distribution: Coasts of China.

7.2.2 Paralichthodes Group

Genera: One genus – Paralichthodes – with one

recent species from the coasts of South Africa.

Definition and relationship: Otoliths of Parali-

chthodes are very similar to those of Psettodes and

Tephrinectes in many plesiomorphic characters.

These are the clear anterior opening of the sul-

cus, the long an narrow cauda with its inclined

tip and the incomplete circumsulcal depression.

Like in Psettodes the ostium is markedly shorter

than the cauda. The inclination of the caudal tip

is even stronger than in Psettodes, and in fact the

strongest of its kind to be found in flatfishes.

Clearly this is one of the most plesiomorphic oto-

lith patterns to be found in Pleuronectiformes next

just to Psettodidae.

Paralichthodes is always right eyed. In shape

and general appearance it resembles the left eyed

Citharidae but also the right eyed Brachypleuri-

dae. Most other characters of Paralichthodes are

Piscium Catalogus, Part Otolithi piscium, Vol. 2

not particularly primitive except for the olfactory

laminae with the long rachis.

NORMAN (1934) had placed Paralichthodes

in the family Pleuronectidae, but in a separate

subfamily Paralichthodinae. In recent literature

Paralichthodes is often associated with another

Pleuronectid subfamily, the Samarinae (NELSON

1984), however, HENSLEY & AHLSTROM (1984)

regarded this genus as a Pleuronectid of uncer-

tain relationship. As it seems otoliths point to a

radically different systematic allocation, possibly

close to or within the Citharidae. The only reason

that makes me hesitate is the fact that Citharidae

are left eyed. The right eyed Brachypleuridae

would have been an alternative. They have been

regarded as a subfamily of the Citharidae by

HUBBS (1945), who established the family. How-

ever, otoliths of Brachypleura and Lepidoblepharon

have nothing in common with those of Paralich-

thodes (see respective entry).

Paralichthodes GILCHRIST 1902

Type-species: Paralichthodes algoensis GILCHRIST

1902

Diagnosis: Thin, moderately elongate otoliths;

ventral rim gently curving, posterior and anteri-

or tips broadly rounded, blunt; index l:h 1.6 to

1.8.

Ostium widened, anteriorly open, somewhat

deepened, considerably shorter than cauda. Cau-

da long, narrow, with rounded and inclined pos-

terior tip. Index ol:cl 0.75-0.85. Dorsal and ven-

tral depression not connected around caudal tip,

not forming a circumsulcal depression. Ventral

depression extremely indistinct; dorsal depres-

sion also very shallow.

Inner face slightly convex; outer face slightly

concave, smooth. Rims sharp, thin, smooth to

slightly undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

algoensis 1.6-1.8 about 4 0.75-0.85 1.6-1.7 about 3.5

Side dimorphism: Not apparent.

Species and distribution: One recent species –

P. algoensis from the coasts of South Africa. There

is also fossil otolith based species from the Lower

Eocene of France – genus aff. Psettodes bavayi

(NOLF 1988) which bears a lot of resemblance

with P. algoensis and alternatively could be placed

in this genus as well (for details see entry to g. aff.

Psettodes bavayi).

Figs. 42-45: Tephrinectes sinensis (LACEPEDE 1802) – 10 ×

42a

42b

42c

Schwarzhans: Pleuronectiformes

Paralichthodes algoensis GILCHRIST 1902

Figs. 46-47

Investigated otoliths: 2 otoliths (left and right

side) from off Durban, South Africa, BMNH

1919.9.12.48.

Remarks: Both extracted otoliths have been

somewhat affected by formalin. In particular the

dorsal rim is incomplete. Other characters, how-

ever, in particular those of the sulcus are very

well preserved.

Recently, SMALE et al. (1995) have figured

two complete specimens of this species, wich

support above analysis, figures and descriptions.

Otolith size is only about 3.5 mm but pertinent

diagnostic features seem to be fully developed.

Distribution: South Africa, from Mossel Bay to

Delagoa Bay in 1-100 m.

7.2.3 Ammotretis Group

Genera: In this group I have united the genera

Colistium, Ammotretis, Oncopterus, Psammodiscus

and Taratretis of NORMAN’s Rhombosoleinae.

Psammodiscus, of which otoliths are unknown, is

placed here because NORMAN has regarded it

as related to Oncopterus, and so is Taratretis which

has been erected more recently. Azygopus (of Pleu-

ronectidae, see respective entry) could also alter-

natively be placed in this group and was includ-

ed in the Rhombosoleinae by NORMAN. All these

genera are endemic to the southern oceans, chief-

ly around Australia and New Zealand except for

Oncopterus which occurs along the coasts of south-

eastern South America.

Definition and relationship: Otoliths of the

Ammotretis Group are characterized by a unique

combination of very plesiomorphic and

(aut)apomorphic characters. Plesiomorphic char-

acters are the clear sulcus opening, the somewhat

widened ostium, the narrowed cauda which usu-

ally is slightly longer than the ostium, and the

extreme feeble development of the incomplete

dorsal and ventral depression. I would think that

these otoliths may not have been recognized as

representatives of Pleuronectiformes when inves-

tigated isolated and without the knowledge of

the fishes from which they have been extracted.

Apomorphic characters are the development of

the caudal tip which is widened in Colistium and

pointed in a very distinctive way in Ammotretis

and Oncopterus. Also these otoliths are extremely

small in comparison to the size of the fish or the

head. Otoliths extracted from Oncopterus darwini

and Ammotretis elongatus of a SL of more than

200 mm was found to be less than 2 mm long.

Otolith of similar sizes are found in Pleuronec-

tids, Bothids, Soleids or Cynoglossids in fishes

the size of 40 to 80 mm (taking head proportions

into consideration this disproportion would even

become larger).

The fishes themselves, however, are by no

means plesiomorphic in appearance. In fact,

Ammotretis and Colistium were noted by NOR-

MAN (1934) to be the ones exhibiting some su-

perficial resemblance with Soleids which he re-

garded as a convergent evolution. (Another ge-

nus mentioned in this respect was Peltorhamphus,

which according to otolith analysis indeed should

be placed in the Soleidae – see respective entry.)

If there is a true plesiomorphic character in the

fishes of this group it is probably the symmetrical

nature of the nasal organ (and possibly the olfac-

tory laminae in Oncopterus and Psammodiscus).

Specialized characters are the commencement of

Figs. 46-47: Paralichthodes algoensis GILCHRIST 1902 – 15 ×

47a

47b

Piscium Catalogus, Part Otolithi piscium, Vol. 2

the dorsal fin in advance of the nostrils of the

blind side, the small narrowly placed eyes, the

strongly asymmetrical nature of mouth and den-

tition, the toothless vomer, the fusion of the pelvic

fin of the ocular side with the anal fin (in Ammo-

tretis and Colistium) and the enlargement of the

number of gill rakers (in Colistium).

Otolith analysis indicates that the Rhomboso-

leinae as understood by NORMAN (1934) do not

form a homogenous unit in a phylogenetic sense.

The five genera of the Ammotretis Group instead

seem to form a more natural unit to be separated

not only from the other genera of the so-called

Rhombosoleinae but perhaps from the Pleu-

ronectidae altogether. In my opinion this group

is of pre-pleuronectid origin, split off early from

the main stem of the Pleuronectoidei probably at

about the Citharid level in LAUDER & LIEM’s

(1984) cladogram. Their degree of specialization

in particular in respect to the fish-morphology

would then be regarded as autapomorphic ex-

cluding them from a close relationship with oth-

er plesiomorphic groups such as Psettodidae,

Citharidae, Tephrinectes or Paralichthodes. Based

on otolith analysis I would recommend to estab-

lish a separate and new pleuronectoid family for

the five genera of the Ammotretis Group.

Colistium NORMAN 1926

Type-species: Ammotretis nudipinnis WAITE 1911

Diagnosis: Moderately thickset and not very

elongate otoliths; ventral rim rather flat, dorsal

rim with broad mid- to postdorsal angle, poste-

rior tip blunt, rostrum short, massive, with infra-

median position; index l:h 1.4 to 1.6. Otolith size

up to 4 mm.

Ostium slightly widened, anteriorly open,

somewhat deepened, usually shorter than cau-

da. Cauda longer, narrower anteriorly but wid-

ened posteriorly, somewhat deepened, with

rounded and very slightly inclined posterior tip.

Index ol:cl quite variable, 0.75 to 1.3. Dorsal and

ventral depression not connected around caudal

tip, not forming a circumsulcal depression. Ven-

tral depression indistinct, dorsal depression bare-

ly visible. This results in a relatively smooth in-

ner face, except for the depressed sulcus.

Inner face convex; outer face slightly concave,

with some irregular ornamentation. Rims mod-

erately sharp, irregularly crenulated and undu-

lating.

Measurements:

l:h h:t ol:cl oh:ch con.i

nudipinnis 1.50 about 3 0.75 nm about 3.5

guentheri 1.45-1.55 3.0-3.5 1.0-1.3 1.1-1.5 about 3.5

Discussion: Otoliths of Colistium differ from

those of Ammotretis and Oncopterus in the round-

ed somewhat widened caudal tip and the some-

what larger size that they can reach (3 to 4 mm).

In this respect their otolith pattern looks more

“primitive” than that of the other two genera.

The characters of the fishes, however, suggest

Colistium to be the most apomorphic genus in

this group.

Side dimorphism: See entry to C. guentheri.

Species and distribution: Two recent species

both endemic to New Zealand – C. nudipinnis and

C. guentheri.

Fig. 48: Colistium nudipinnis (WAITE 1911) – 15 ×

Schwarzhans: Pleuronectiformes

Colistium nudipinnis (WAITE 1911)

Fig. 48

Investigated otoliths: One otolith (right side)

from New Zealand, AUG-V 290 (pars; coll. Gren-

fell).

Discussion: The single otolith available from

C. nudipinnis can readily be distinguished from

those of C. guentheri by the following characters:

the massive postdorsal angle, the considerably

widened and deepened caudal tip and the close

approach of the caudal tip of the sulcus towards

the posterior tip of the otolith. The latter character

is unique amongst Pleuronectiform otoliths resul-

ting in a very unusual flatfish otolith morphology.

Distribution: The species is endemic to New

Zealand.

Colistium guentheri (HUTTON 1873)

Figs. 49-51

Investigated otoliths: 3 otoliths, 2 (left and right

side, figs. 49-50) off Wellington, BMNH

1923.11.5.5, one otolith (right side, fig. 51), AUG-

V 294 (coll. Grenfell).

Side dimorphism: Of the two otoliths obtained

from the left and right side of one fish specimen

the right handed otolith shows a more distinct

and broad excisura. The additional otolith, how-

ever, which is also right handed, does not show

an excisura at all.

Ontogeny and variability: The two right hand-

ed otoliths available differ from each other in the

development of the excisura, the proportion of

ostium length to cauda length and the expression

of the dorsal rim.

Figs. 49-51: Colistium guentheri (HUTTON 1873) – 15 ×

49a

49b

49c

51c

51b

51a

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: C. guentheri differs from C. nudipin-

nis in the less prominent medio- to postdorsal

angle, the more regularly narrowed cauda which

terminates at some distance from the posterior

tip of the cauda, and the proportionally some-

what longer ostium.

Distribution: This species is endemic to New

Zealand.

Ammotretis GÜNTHER 1862

Type-species: Ammotretis rostratus GÜNTHER

1862

syn. Tapirisolea RAMSAY 1883 (type-species:

N.N.)

Diagnosis: Thin, very small, compressed otoliths,

almost rectangular to irregularly rounded in out-

line; ventral and dorsal rim rather flat, the latter

often with postdorsal angle, posterior tip blunt

sometimes rounded, anterior rim blunt too, ros-

trum moderately strong or reduced in size, ex-

cisura and antirostrum relatively well developed;

index l:h 1.1-1.5. Otolith size may not exceed

3 mm.

Ostium somewhat widened, anteriorly open,

somewhat deepened, slightly longer than cauda.

Cauda narrower than ostium, slightly widened

in the middle and with a tapering and pointed

tip. Dorsal and ventral depression not connected

around caudal tip, not forming a circumsulcal

depression. Ventral depression short, feeble, dor-

sal depression also weak.

Inner face slightly convex; outer face slightly

concave to flat, rather smooth. Rims smooth,

except for ventral rim which may be slightly

undulated.

Measurements:

l:h h:t ol:cl oh:ch con.i

rostratus 1.40-1.45 3.2-3.5 1.15-1.30 1.2-1.5 about 3

tudori 1.45 nm 1.2 1.25 nm

elongatus 1.10 3.1 1.0 1.2 3.5

Side dimorphism: Not apparent.

Discussion: Ammotretis otoliths no doubt resem-

ble those of Colistium. They are, however, more

compressed with a more reduced rostrum and

exhibit a different type of caudal tip. In these two

respects Oncopterus resembles even better.

Species and distribution: Four to five recent

species, all from southern temperate Australia:

Figs. 52-55: Ammotretis rostratus GÜNTHER 1862 – 15 ×

52a

52c

52b

53a

53c

53b

Schwarzhans: Pleuronectiformes

A. rostratus, A. brevipinnis, A. tudori, A. macrolepis

(possibly syn. A. tudori) and A. elongatus. Of these

A. rostratus is the most widely distributed one.

Ammotretis rostratus GÜNTHER 1862

Figs. 52-55

syn. Ammotretis rostratus vel adspersus KNER 1869

syn. Rhombosolea bassensis CASTELNAU 1872

syn. Solea uncinata KLUNZINGER 1880

syn. Ammotretis zonatus MACLEAY 1883

syn. Ammotretis ovalis SAVILLE-KENT 1889

Investigated otoliths: 4 otoliths, one (left side,

fig. 52) from the coast of Victoria, Australia, off

Melbourne, ZMH 20008, three (two left, fig. 53-54;

one right, fig. 55) from off Hobart, Tasmania, ZMH

Ot. 2.1.1995.1-2 (leg. BMNH 1934.3.18.1-10) and

BMNH 1934.3.18.1-10.

Variability: The otoliths of the three specimens

investigated do not differ greatly from each oth-

er. One of the specimens (fig. 52) shows a more

widened ostium than the others.

Discussion: A. rostratus differs from A. tudori and

A. elongatus in the more massive posterior tip of

the otolith and the reduced rostrum.

Distribution: Temperate Australia, from Port

Jackson in New South Wales, Victoria, South

Australia, southern Western Australia and Tas-

mania in shallow water.

Ammotretis tudori McCULLOCH 1914

Fig. 56

Investigated otoliths: One otolith (left side) from

off South Australia, BMNH 1925.3.20.1.

Discussion: Similar to A. rostratus, but with a

more prominent rostrum and a more rounded

posterior tip.

Distribution: Temperate Australia, in Victoria,

South Australia and Tasmania.

Ammotretis elongatus McCULLOCH 1914

Fig. 57

Investigated otoliths: One otolith (right side)

from Kangaroo Isl., off South Australia, BMNH

1925.1.26.3.

Discussion: Otolith extremely small in compar-

ison to size of fish. Outline more rounded than in

the other two species investigated and with a

rather strong rostrum like A. rostratus.

Distribution: Off South Australia.

Oncopterus STEINDACHNER 1875

Type-species: Oncopterus darwini STEINDACHN-

ER 1875

syn. Curioptera WHITLEY 1951 (unneeded sub-

stitute for Oncopterus)

Diagnosis: Thin, compressed otoliths; ventral

rim rather flat, dorsal rim gently curving with a

prominent predorsal dome, posterior tip broadly

rounded, anterior rim blunt; index l:h 1.1. Oto-

liths size may not exceed 2 mm.

Ostium slightly wider than cauda, anteriorly

open, somewhat deepened, shorter than cauda.

Cauda slightly widened in the middle and with

a tapering and pointed tip. Index ol:cl about 0.8.

Dorsal and ventral depressions feeble not con-

nected around caudal tip, not forming a circum-

sulcal depression.

Inner face very slightly convex, almost flat;

outer face flat, smooth. Rims sharp, smooth.

Fig. 56: Ammotretis tudori McCULLOCH 1914 – 15 ×

Fig. 57: Ammotretis elongatus McCULLOCH 1914 – 15 ×

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Measurements:

l:h h:t ol:cl oh:ch con.i

darwini 1.1 about 3.5 0.8 about 1.0 nm

Side dimorphism: No data.

Discussion: Otoliths of Oncopterus are extreme-

ly small in comparision to the size of the fish

(ratio about 1:100). Otherwise they resemble well

otoliths of Ammotretis, particularly in the outline

of the cauda and the compressed appearance.

Species and distribution: A single recent spe-

cies – O. darwini – from the southeastern coast of

South America.

Oncopterus darwini STEINDACHNER 1875

Fig. 58

Investigated otoliths: One otolith (right side)

from off Patagonia, South-East America, BMNH

1930.9.4.21-22.

Remarks: Due to the small size and the fragile

nature of the otolith the only otolith successfully

extracted from the fish has been somewhat dam-

aged. The rostral portion of the otolith broke away

when touched with the tweezers. However, it is

quite apparent that the missing rostrum must

have been a very short and blunt one.

Distribution: This species is exclusively known

from the southeastern coast of South America,

from Rio Grande do Sul (southernmost Brazil) to

San Matias Bay (Argentina).

Psammodiscus GÜNTHER 1862

Type-species: Psammodiscus ocellatus GÜNTHER

1862

Remarks: Psammodiscus is a monospecific genus.

Until very recently only the four type specimens

were known. They are kept in the BMNH and I

opened two of them in order to extract otoliths.

Unfortunately, they seem to be completely dis-

solved by formalin. In a report of fishes trawled

of southern Indonesia and northwestern Australia

GLOERFELT-TARP & KAILOLA (1984) addition-

al reference is given (coll CSIRO), but I did not

have the opportunity to investigate any of the

new specimens.

In the absence of otoliths to be investigated

Psammodiscus is included in the Ammotretis Group

following NORMAN (1934), who related it to On-

copterus.

Species and distribution: The type specimens

(and for a long time the only specimens) were

lacking geographical coordinates. The recent ref-

erence by GLOERFELT-TARP & KAILOLA is from

northern Western Australia, vicinity of Barrow

Island.

Taratretis LAST 1978

Type-species: Taratretis derwentensis LAST 1978

Remarks: Taratretis is a monospecific genus en-

demic to the shores of Tasmania (Australia). Oto-

liths have not been available for investigation.

7.3 Citharidae

Genera: As understood here, I have reduced the

Citharidae to the Citharinae of HUBBS (1945) and

included the recent genera Citharus, Paracitharus,

Citharoides and the fossil otolith based genus

Rhombocitharus. Another fossil otolith based ge-

nus – Citharopsettodes – was found to be a junior

synonym of the living Paracitharus.

Definition and relationship: When HUBBS

(1945) established the family Citharidae he dis-

cussed at length the relatively primitive nature of

the genera he included, but also one character

(position of the vent on the eyed side) which could

be regarded as an autapomorphic character of

the family. He included left eyed (Citharinae) and

right eyed (Brachypleurinae) genera.

Otoliths indicate instead that the two subfam-

ilies may not be so closely related. Brachypleuri-

nae (which show a number of specialized charac-

Fig. 58: Oncopterus darwini STEINDACHNER 1875 –15 ×

Schwarzhans: Pleuronectiformes

ters; see respective entry) are here separated from

the Citharidae and constitute a family by them-

selves. The remainder, the left eyed Citharidae,

form a cohesive group in otolith morphology as

well. Paralichthodes (see respective entry) is, per-

haps, a case of a dextral flatfish whose otoliths do

resemble those of the sinistral Citharidae. In a

recent cladistic analysis CHAPLEAU (1993) also

regarded the Citharidae as polyphyletic but

placed the dividing line between Citharoides and

Citharus. He suggested that the dextral Lepidoble-

pharon and the sinistral Citharoides form a trichot-

omy with all remaining pleuronectiforms, with

the sinistral Citharus and the dextral Brachypleura

being in the latter clade. Otolith analysis, howev-

er, clearly contradicts this alignment and in stead

suggests that the dividing line should be between

the left eyed and right eyed Citharidae (Citharidae

and Brachypleuridae as presented here).

Citharid otoliths again are characterized by a

number of plesiomorphic characters. These are

the sulcus proportions in which the ostium is

shorter than the cauda or both are of about equal

length, and the narrow cauda which is sometimes

slightly inclined posteriorly. Also the ostium is

open anteriorly. The circumsulcal depression is

much better developed than in the Psettodidae

and the “genera of uncertain relationship”, but

still not completely connected around the tip of

the cauda.

In conclusion, otoliths of the Citharidae sensu

stricto support HUBBS’ (1945) concept of the in-

termediate phylogenetic position of this group.

The pattern is also perfectly in accordance with

LAUDER & LIEM’s (1984) cladogram which

shows Citharidae branching off after Psettodidae

and before the main diversification in the Pleu-

ronectoidei commenced. Their fossil abundance,

particularly in the early Tertiary, further supports

the antiquity of the family.

Ontogeny: Citharid otoliths may reach up to 10

mm in length, but rarely exceed 7 mm. Since on-

togenetic changes are generally slight, otoliths of

4 to 5 mm length are usually adequate for specif-

ic identification, but in some of the smaller fossil

species otoliths of just 3 mm can be sufficient in

size.

Distribution: The present distribution of cith-

arids is somewhat patchy, clearly the relict of a

once much wider distribution. Furthermore, all

three genera exhibit an antitropical distribution

pattern: Citharus in the Mediterranean and the

Northeast Atlantic (but as an exception also along

the coasts of tropical West Africa), Paracitharus

along the coasts of South and southern East Af-

rica, and Citharoides from Japan and Korea.

Citharus RÖSE 1793

Type-species: Pleuronectes linguatula LINNAEUS

1758

syn. Eucitharus GILL 1889 (type-species: Pleu-

ronectes linguatula)

syn. Chopinopsetta WHITLEY 1931 (type-species:

Pleuronectes linguatula)

Remarks: I have followed HUBBS’ (1945) re-

marks in accepting Citharus as a valid genus name.

Diagnosis: Thin, moderately elongate otoliths;

ventral rim deeply curving, deepest midventral-

ly, dorsal rim usually with distinct mid- and post-

dorsal angles, posterior tip rounded, blunt, or with

obtuse angle, anterior rim with short massive

rostrum, but without excisura; index l:h 1.4 to

2.0. Otolith size up to 7 mm.

Ostium slightly wider than cauda and usual-

ly shorter too, anteriorly open, rather shallow.

Cauda narrow, usually straight, but sometimes

just very faintly inclining towards the tip, reach-

ing close to the posterior tip of the otolith. Dorsal

and ventral depressions well developed and large,

but not completely connected around caudal tip

to form a circumsulcal depression.

Inner face almost flat; outer face flat to slight-

ly concave, smooth to slightly ornamented. Rims

sharp, often crenulated or irregularly undulat-

ing.

Measurements:

l:h h:t ol:cl oh:ch con.i

linguatula (ad.) 1.55-1.95 3.0 0.60-0.65 1.50-1.55 5.5

linguatula (juv.) 1.50-1.70 3.0-3.5 0.75-0.90 1.45-1.65 about 6

†balearicus 1.45-1.55 3.0-3.5 0.65-0.75 1.30-1.45 4-5

†lusitanicus 1.55-1.75 about 4 0.75-0.95 1.35-1.65 about 5

sp.(STEUR.) 1.40-1.50 0.75 1.70

†schuberti 1.60-1.65 <3.0 0.65 1.70-2.00 about 5

Side dimorphism: Not apparent.

Discussion: Otoliths of Citharus do not differ

much from those of the two other recent genera

of the family – Paracitharus and Citharoides. As it

Piscium Catalogus, Part Otolithi piscium, Vol. 2

seems the outline of Citharus otoliths usually is

more angular, particularly the dorsal rim. In Parac-

itharus the ostium is nearly of the length of the

cauda. Citharoides otoliths are more elongate than

the other two and exhibit a more gently curving

outline.

Species and distribution: One recent species:

C. linguatula known from the Mediterranean and

the eastern Atlantic from Portugal to Angola. In

addition there are 4 nominal fossil species de-

scribed from European and North African sedi-

ments: C. balearicus from the Pliocene of Mallorca

(Spain), SW-France and NW- Morocco, C. lusitani-

cus from the Lower and Middle Miocene of Por-

tugal, France, Austria and Poland (both Parate-

thys), C. schuberti from the Upper Miocene and

Lower Pliocene of Italy. C. miocenicus from the

Lower Miocene of Germany was based on a sin-

gle non-diagnostic juvenile specimen and must

therefore be regarded as of doubtful nature. How-

ever, STEURBAUT (1984) figured a Citharus sp.

from the Lower Oligocene to Middle Miocene of

France, which in fact may very well represent a

fourth species. I agree with STEURBAUT to leave

this species in open nomenclature until more

material becomes available from the North Sea

Basin and the taxonomical status of C. miocenicus

becomes resolved. The definition and delimita-

tion of some of the fossil species is not as yet

sufficiently validitated (see respective entries).

Citharus linguatula (LINNAEUS 1758)

Figs. 59-64

syn. Pleuronectes macrolepidotus BLOCH 1787

syn. Pleuronectes citharus SPINOLA 1807

syn. Pleuronectes patarachia NARDO 1847

Investigated otoliths: 6 otoliths, 2 (left and right

side, figs. 62-63) and 1 (right side, fig. 64) from off

Neapel, ZMH 19951, 3 (right side, figs. 59-61) from

off Angola, ZMH Ot. 2.1.1995.3-4 (leg. BMNH

1930.5.6.27-29) and BMNH 1930.5.6.27-29.

Remarks: I have followed NORMAN’s view in

accepting linguatula as valid species name. This

also rules out possible confusion with Citharoides

macrolepidotus HUBBS 1915.

Ontogeny and variability: The 6 otoliths inves-

tigated are from two different sizes. Three are of

relatively small size (about 4 mm, figs. 62-64) and

have not developed all pertinent diagnostic fea-

tures, whereas the other three are more than 6 mm

(figs. 59-61) long and are typical adult specimens.

A larger set of recent otoliths is figured by

CHAINE (1936) of sizes up to 7 mm. Larger oto-

liths (more than 5 mm of length) are slightly more

elongate, lack the fine crenulation of the rims,

and have developed the postdorsal portion more

strongly, whereas the middorsal portion is

more flat.

Variability is not very prominent and restrict-

ed to minor variations of the proportions and in

the expression of the dorsal rim.

Discussion: The differentiation of C. linguatula

from the various nominal fossil species is by no

means clear. It seems that, except for C. schuberti,

the fossil species in question have achieved a

mature state of the morphological pattern at

smaller sizes. NOLF (1985) has tentatively syno-

nymized C. balearicus with the recent species.

From my investigations, however, it seems that

otoliths of C. balearicus (and C. sp. too) regularly

are somewhat more compressed than those of

C. linguatula. C. lusitanicus exhibits similar pro-

portions than C. linguatula but has a more pro-

nounced mediodorsal angle and seems also slight-

ly more thinset. C. schuberti finally resembles the

recent species both in proportions and outline

except for its very characteristic vertically cut

posterior rim, and in its being more thickset. More

material of C. balearicus and C. lusitanicus will be

needed before the validity of these two species

can be proven in comparison with the recent C. lin-

guatula.

Distribution: Mediterranean and eastern Atlantic

from Portugal to Angola on the continental shelf.

Citharus lusitanicus JONET 1972

Figs. 65-73

syn. Eucitharus rhenanus KOKEN – WEINFURT-

ER 1952: pl. 2, figs. 9-10

syn. Eucitharus lusitanicus JONET 1972 – JONET

1972: fig. 12; pl. 4, figs. 131-133

syn. Citharus lusitanicus – SMIGIELSKA 1979: figs.

34-35; pl. 8, figs. 6-8

Schwarzhans: Pleuronectiformes

syn. Eucitharus lusitanicus – JONET 1980: pl. 4,

fig. 3

syn. Citharus lusitanicus – STEURBAUT & JONET

1982: pl. 4, figs. 14-16

?syn. Citharus lusitanicus – STEURBAUT 1984: pl.

34, figs. 11-16

syn. Citharus lusitanicus – RADWANSKA 1992:

fig. 151; pl.35, figs. 3-6

?syn. Citharus sp.1 – RADWANSKA 1992: fig. 152;

pl. 36, figs. 14-16

syn. Citharus sp.2 – RADWANSKA 1992: fig. 153;

pl. 36, figs. 1-2

Investigated otoliths: 97 otoliths, 9 (figs. 65-67)

from Costa da Caparica, Portugal, Burdigalian,

Lower Miocene (topo- and strati-typical), coll.

Schwarzhans, 88 (figs. 68-72) from Korytnica,

Poland, Badenian, Middle Miocene, ZPalUW-RaK

408-417 (coll. Radwanska).

Figs. 59-64: Citharus linguatula (LINNAEUS 1758) – 10 ×

59a

59b

62c

62a

62b

64a

64b

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ontogeny and variability: Two otoliths figured

are 3.5 mm (fig. 65) and 4 mm (fig. 66) long. They

seem to have developed all pertinent diagnostic

features indicating that otoliths of this species

mature at smaller sizes than those of the recent

C. linguatula. The largest specimen known so far

is JONET’s type of slightly over 5 mm of length.

The smallest specimen known to me (fig. 67) is

3 mm long and shows the kind of marginal crenu-

lation typical for juvenile Citharus otoliths (see

C. linguatula). – The otoliths described from the

Middle Miocene of Poland by RADWANSKA

(1992) (see also figs. 68-72) perfectly fit with the

specimens from the Middle Miocene of Portugal.

A specimen originally described as Citharus sp.1

by RADWANSKA is considerably more com-

pressed, thus resembling STEURBAUT’s Citha-

rus sp. from the Oligocene and Miocene of France.

Since the specimen from Poland is an unique find-

ing it could also represent a teratological effect. I

have therefore selected to regard it as C. aff. lusi-

tanicus (fig. 73). Two other otoliths from Poland –

described as Citharus sp.2 by RADWANSKA

(1992) – in my opinion just represent eroded spec-

imens of C. lusitanicus (not figured).

Discussion: C. lusitanicus very closely resembles

the recent C. linguatula and the Pliocene C. ba-

learicus (see respective entries for discussion).

Fig. 73: Citharus aff. lusitanicus JONET 1972 – 10 ×

Figs. 65-72: Citharus lusitanicus JONET 1972 – 10 ×

66a

67a

68a

66b

67b

68b

Schwarzhans: Pleuronectiformes

Distribution: Lower to Middle Miocene of Por-

tugal, France (Aquitaine Basin), Austria and Po-

land (Paratethys).

Citharus balearicus BAUZA RULLAN 1955

Figs. 74-76

syn. Eucitharus balearicus BAUZA RULLAN

1955 – BAUZA RULLAN 1955: pl. 8, fig. 16

syn. Eucitharus balearicus – BAUZA RULLAN

1964: pl. 4, fig. 5

syn. Eucitharus balearicus – BAUZA RULLAN

1972: fig. 17

syn. Citharus linguatulus (LINNAEUS) – NOLF

& CAPPETTA 1988: pl. 18, fig. 14

Investigated otoliths: 5 otoliths (figs. 74-76) from

the river banks of the Oued Beth near Dar Bel

Hamri, NW-Morocco, Sands of Dar Bel Hamri,

Lower Pliocene, coll. Schwarzhans.

Ontogeny and variability: The otoliths investi-

gated are between 3.5 and 4.5 mm in length. They

do not exhibit any significant ontogenetic chang-

es or variability. Their relatively smooth outline

indicates a mature ontogenetic stage of the oto-

lith morphology.

Discussion: NOLF (1985) has synonymized

C. balearicus with the recent C. linguatula. In my

opinion, however, the fossil specimens are always

more compressed than recent ones of the same

ontogenetic stage. I therefore provisionally keep

C. balearicus as a valid species. Differentiation from

C. lusitanicus and C. sp. (sensu STEURBAUT,

1984) both from the Miocene is much less obvi-

ous. C. lusitanicus mainly differs in being more

elongate, but there are indications that interme-

diate forms may exist. Differentiation of the two

species will then become very difficult if at all

possible. C. sp. (sensu STEURBAUT) is just slight-

ly more compressed and shows a more regularly

rounded outline.

Distribution: Lower Pliocene of SW-France and

NW-Morocco and Upper Pliocene of Mallorca

(Spain).

Citharus sp. (sensu STEURBAUT 1984)

?ref. Eucitharus miocenicus WEILER 1942 – WEI-

LER 1942: pl. 4, fig. 36

ref. Citharus miocenicus – STEURBAUT 1979:

pl. 11, fig. 16

?ref. Citharus miocenicus – NOLF & SMITH 1983:

pl. 2, fig. 21

ref. Citharus sp. – STEURBAUT 1984: pl. 34,

figs. 3-9

Remarks: WEILER’s original description was

based on a juvenile not diagnostic otolith of only

2 mm of length. NOLF & SMITH (1983) figured

another specimen from the Lower Miocene of the

North Sea Basin (Belgium), which is slightly larg-

Figs. 74-76: Citharus balearicus BAUZA RULLAN 1955 – 10 ×

74b

74a

74c

Piscium Catalogus, Part Otolithi piscium, Vol. 2

er (2.5 mm), but still does not exhibit all neces-

sary diagnostic features. Besides the two small

specimens STEURBAUT (1984) has figured oto-

liths of up to 4 mm in length. Although originat-

ing from different basins (Aquitaine Basin) they

could possibly represent the same species as the

specimens from the North Sea Basin. However,

until more material becomes available from the

North Sea Tertiary it seems advisable to follow

STEURBAUT’s recommendation to leave these

otoliths in open nomenclature.

Ontogeny and variability: Otoliths of C. sp. seem

to have reached morphological maturity at rela-

tively small sizes of about 3 mm. However, even

larger specimen of up to 4 mm occasionally ex-

hibit some fine marginal crenulation. The type

specimen of C. miocenicus was only 2 mm in length

and is not diagnostic in its outline. It must be

considered as a juvenile.

Variability is limited to details of the outline,

ornamentation and slight variations of the length

to height ratio.

Discussion: C. sp. (sensu STEURBAUT 1984) as

defined here is very similar to C. balearicus from

the Pliocene of the Mediterranean. Major differ-

ence is only the more regularly rounded outline

observed in C. sp. However, more and larger

specimens of both species are needed to validate

the diagnostic value of this character.

Distribution: Lower Oligocene to Lower Mi-

ocene of France (Aquitaine Basin) and possibly

also Lower Miocene of the North Sea Basin (Ger-

many and Belgium).

Citharus schuberti BASSOLI 1906

Fig. 77

syn. Citharus schuberti BASSOLI 1906 – BASSOLI

1906: pl. 6, fig. 9

syn. Eucitharus schuberti – ANFOSSI & MOSNA

1979: pl. 4, fig. 10

syn. Citharus schuberti – NOLF & STEURBAUT

1983: pl. 7, fig. 25

Investigated otoliths: BASSOLI’s type-specimen

from Montegibbio, Italy, Tortonian, Upper Mi-

ocene, IPUM 16629.

Discussion: Although only few specimens so far

have been recorded they are nevertheless easily

recognized by their flat dorsal rim, the vertically

cut posterior rim and the more thickset nature.

Otherwise, in outline and proportions, they re-

semble closest the recent C. linguatula.

Distribution: Known from the type-specimen

from the Upper Miocene of Italy and few addi-

tional specimens from the Lower Pliocene of Ita-

ly. All records so far are from relatively deep

marine environments. C. schuberti does not seem

to occur simultaneously with C. balearicus al-

though found in the same general area and strati-

graphic sequence. Possibly, C. schuberti represents

a deeper water species and C. balearicus its shal-

low water equivalent. C. schuberti is one of the

few fossil Pleuronectiform species collected from

deeper marine environments.

Fig. 77: Citharus schuberti BASSOLI 1906 – 10 ×

Schwarzhans: Pleuronectiformes

Paracitharus REGAN 1920

Type-species: Arnoglossus macrolepis GILCHRIST

1905

syn. Citharopsettodes SCHWARZHANS 1978

(type-species: Citharopsettodes angustus

SCHWARZHANS 1978)

Diagnosis: Moderately thin, roundish to mod-

erately elongate otoliths; ventral rim deeply curv-

ing, deepest midventrally, dorsal rim usually with

distinct pre- and postdorsal angles, posterior tip

rounded or angular, anterior rim with short mas-

sive rostrum, but without excisura; index l:h in

adults 1.5 to 2.0. Otolith size up to 7 mm.

Ostium very slightly wider than cauda and of

about equal length. Cauda narrow, usually

straight, but sometimes just very faintly inclining

towards the tip, reaching close to the posterior

tip of the otolith. Dorsal and ventral depressions

well developed and large, but not completely

connected around caudal tip to form a circum-

sulcal depression.

Inner face almost flat; outer face flat to slight-

ly concave, smooth to slightly ornamented. Rims

sharp, smooth in adults, crenulated or irregular-

ly undulating in smaller specimens.

Measurements:

l:h h:t ol:cl oh:ch con.i

macrolepis (ad.) 1.60 about 2.5 1.0-1.1 1.4-1.5 about 5

macrolepis (juv.) 1.35-1.45 about 3

†angustus 2.00 about 3 0.9 1.15 about 6

Side dimorphism: Not apparent.

Discussion: Otoliths of Paracitharus very closely

resemble those of Citharus. Main differences are

the proportions of the sulcus. From the point of

otolith morphology alone this may not warrant

separation in two genera.

Species and distribution: One recent species –

P. macrolepis – from South and SE-Africa (Natal to

Kenya) and one fossil species – P. angustus – from

the Lower Pliocene of Italy.

Paracitharus macrolepis (GILCHRIST 1905)

Figs. 78-87

Investigated otoliths: 13 otoliths, figured otoliths

10 (left and right side, figs. 78-82, 84-87) from off

Zanzibar, ZMH Ot. 3.1.1994.1-10 (leg. BMNH

1939.5.24.1706-1717), 2 BMNH 1939.5.24.1706-

1717, 1 otolith (right side, fig. 83) from off South

Africa, ZMH Ot. 3.1.1994.11 (leg. ZMUC).

Ontogeny and variability: From this species I

have available a continuous set of otoliths of

variable sizes from about 2.5 mm to 7 mm in

length. The smallest otoliths up to 2.5 mm (figs.

86-87) exhibit a fairly generalized pattern which

is even difficult to distinguish from Citharus spe-

cies (only valuable difference might be the pro-

portions of ostium to cauda). They are compressed

(ratio l:h 1.35) and show undulated margins. Their

outline is pretty rounded. Otoliths from 3.5 to

5.5 mm (figs. 79-85) are still similar as far as mar-

ginal crenulation is concerned. Ratio l:h ranges

from 1.35 to 1.45. The outline is still very much

rounded, but the postdorsal portion becomes a

little more accentuated. The only large otolith

available (7 mm, fig. 78) is considerably more

elongate (ratio l:h 1.6) and exhibits a completely

smooth outline. Its posterior tip is somewhat

pointed. – It seems that diagnostic valid charac-

ters are only developed in otoliths of about 6 mm

or more.

Discussion: See entry to genus and to P. angus-

tus.

Distribution: Southern Africa, from Natal to

Kenya in moderately deep water (100 to 200 m).

Paracitharus angustus

(SCHWARZHANS 1978)

Fig. 88

syn. Citharopsettodes angustus SCHWARZHANS

1978 – SCHWARZHANS 1978: pl. 10, fig. 123

Investigated otoliths: One otolith (the unique

type-specimen) from Cetona near Siena, Tosca-

na, Italy, Zanclian, Lower Pliocene, SMF P 5696.

Discussion: The single specimen known to date

is a well preserved large otolith of about 7 mm of

length. In ignorance of recent otoliths of Paracitha-

rus I had originally placed this species in a (as-

sumed) fossil genus of its own – Citharopsettodes –

and regarded it as a Psettodidae intermediate in

morphology between that family and the Cith-

aridae. Now, that otoliths of the recent Paracitha-

rus are available it becomes apparent that

Piscium Catalogus, Part Otolithi piscium, Vol. 2

specific separation indubitable. The occurrence

of the genus Paracitharus in the Pliocene of the

Mediterranean indicates that this genus once was

more widely distributed, and that its present dis-

tribution represents a secondary endemism.

P. angustus should belong to the same genus. Gen-

eral appearance and proportions of the sulcus

are practically identical. However, the fossil

P. angustus is considerably more elongate and also

shows a comparatively narrow ostium making

Figs. 78-82: Paracitharus macrolepis (GILCHRIST 1905) – 10 ×

78a

78b

78c

82a

82b

Schwarzhans: Pleuronectiformes

Distribution: Only known from the type-speci-

men from the Lower Pliocene of Italy. Sedimen-

tary environment is deeper marine, off the conti-

nental shelf.

Citharoides HUBBS 1915

Type-species: Citharoides macrolepidotus HUBBS

1915

syn. Brachypleurops FOWLER 1934 (type-species:

Brachypleurops axillaris = Citharoides macrolepi-

dotus)

Diagnosis: Thin, elongate otoliths; ventral rim

gently curving, deepest midventrally, dorsal rim

shallow, without distinct pre- and postdorsal

angles, posterior tip rounded, anterior rim with

short massive rostrum, but without excisura; in-

dex l:h about 2.0. Otolith size reaching at least

6.5 mm.

Sulcus narrow. Ostium almost as wide as cau-

da and also about as long. Cauda narrow, almost

straight, very faintly inclining towards the tip,

reaching close to the posterior tip of the otolith.

Dorsal and ventral depressions well developed

and large, but not completely connected around

caudal tip to form a circumsulcal depression.

Inner face relatively flat; outer face flat to

slightly concave, smooth. Rims moderately sharp,

smooth somewhat undulating posterior-ventrally.

Measurements:

l:h h:t ol:cl oh:ch con.i

macrolepidotus 2.05 <3.0 about 1.0 1.35 about 5

Side dimorphism: No data.

Discussion: Similar to Citharus and Paracitharus

but more elongate, with a smooth dorsal rim, and

a narrow sulcus with ostium and cauda of about

equal length.

Species and distribution: One recent species off

Japan and Korea.

Citharoides macrolepidotus HUBBS 1915

Fig. 89

syn. Brachypleurops axillaris FOWLER 1934

Investigated otoliths: One otolith (right side)

from off Kochi, Japan, ZMH Ot. 2.1.1994.12 (leg.

Sasaki).

Distribution: Off Japan and Korea.

Fig. 88: Paracitharus angustus

(SCHWARZHANS 1978) – 10 ×

Figs. 83-87: Paracitharus macrolepis (GILCHRIST 1905) – 10 ×

Piscium Catalogus, Part Otolithi piscium, Vol. 2

†Rhombocitharus SCHWARZHANS 1994

Type-species: Rhombus rhenanus KOKEN 1891

Diagnosis: Thin, compressed to moderately elon-

gate otoliths; ventral rim deeply curving, deepest

midventrally, dorsal rim usually shallow, with

indistinct predorsal angle and pronounced post-

dorsal portion, posterior tip rounded, sometimes

obtuse angular, anterior rim with very short in-

distinct rostrum, and without excisura; index l:h

1.15 to 1.8. Otoliths small, merely reaching 4 mm.

Ostium about as wide as cauda, about the

same in length or slightly shorter, anteriorly in-

distinctly opened, rather shallow. Cauda narrow,

straight, sometimes tapering, reaching moderate-

ly close to the posterior tip of the otolith. Dorsal

and ventral depressions well developed and large,

incompletely connected around caudal tip to form

a circumsulcal depression.

Inner face almost flat; outer face flat to slight-

ly concave, smooth to slightly ornamented. Rims

sharp, sometimes crenulated or irregularly un-

dulating but mostly smooth.

Measurements

(ab.=about):

l:h h:t ol:cl oh:ch con.i

†biaculeatus 1.55-1.75 ab. 1.0 1.0-1.1

†cauneillensis 1.30-1.40 ab. 3.0 ab. 1.0 ab. 1.0

†circularis 1.35-1.40 0.8-0.9 1.0-1.1

†rhenanus (ad.) 1.55-1.80 ab. 2.0 1.15-1.25 1.05-1.2 ab. 4.5

†rhenanus (juv.) 1.40-1.55 ab. 3.0 1.3-1.7

†rhomboides 1.20 ab. 1.0 ab. 1.0

†novaezeelandiae 1.85 ab. 2.5 1.2 1.3 ab. 4.0

Side dimorphism: Not apparent.

Discussion: Most Rhombocitharus species de-

scribed so far have been based on otoliths of less

than 2.5 mm of length. In fact, the only species of

which larger specimens are known (up to 4 mm)

is R. rhenanus. Analysis of a good ontogenetic

sequence of otoliths of this species have shown

that only otoliths of 3 mm of length or more have

developed the full set of diagnostic valid features.

Principal ontogenetic changes concern the ratio

l:h as can be seen from above listing. Therefore, it

must be concluded that the other four species are

based on juveniles. It is true, however, that even

those juveniles can be distinguished sufficiently

from each other to warrant valid diagnoses, but

one must expect that these will change once larg-

er otoliths become available. For the time being

the four species in question are (tentatively) re-

garded as valid, but it is strongly recommended

that future descriptions of new species should be

based on otoliths of at least 3 mm in length.

Otoliths of Rhombocitharus in many ways are

morphologically intermediate between Cithari-

dae and Scophthalmidae. Many characters such

as outline, general habitus and proportion of

ostium to cauda length resemble citharids. The

narrow ostium which is about the height of the

cauda and the nearly complete circumsulcal de-

pression on the other hand resemble Scophthalmi-

dae and also certain Bothidae. In particular right

handed otoliths of the Scophthalmid genus Lep-

idorhombus are quite similar. Also in Scophthalmi-

dae the ostium usually is only slightly longer than

the cauda (whereas in bothids it is usually about

1.5 to 2 times as long).

In conclusion, features regarded as plesiomor-

phic resemble citharids, whereas features as-

sumed to be apomorphic resemble Scophthalmi-

dae. Therefore, an alternative systematic position

for Rhombocitharus would be to regard it as the

most plesiomorphic member in Scophthalmidae.

Fig. 89: Citharoides macrolepidotus HUBBS 1915 – 10 ×

Schwarzhans: Pleuronectiformes

Species and distribution: Rhombocitharus con-

tains 6 nominally valid fossil species – R. circularis

from the Lower Eocene of England and France,

R. biaculeatus from the Middle Eocene of Belgium

and England, R. cauneillensis from the Upper

Eocene of France (Aquitaine Basin), R. rhomboides

from the Lower Oligocene of northern Germany

and Belgium (North Sea Basin), and R. rhenanus

from the Middle and Upper Oligocene of north-

ern Germany, Belgium and the Netherlands

(North Sea Basin) and from the Middle Oligocene

of the Mainz Basin in Germany. Genus aff. R. no-

vaezeelandiae from the Lower Miocene of New

Zealand is only tentatively included in this ge-

nus and might very well represent a fossil genus

of its own.

Rhombocitharus rhenanus (KOKEN 1891)

Figs. 90-98

syn. Rhombus rhenanus KOKEN 1891 – KOKEN

1891: pl. 5, fig. 12

syn. Solea guestfalicus KOKEN 1891 – KOKEN

1891: pl. 5, fig. 10

Figs. 90-98: Rhombocitharus rhenanus (KOKEN 1891) – figs. 90-97 = 15 ×, fig. 98 = 25 ×

90a

90b

93a

93b

96a

96c

96b

Piscium Catalogus, Part Otolithi piscium, Vol. 2

syn. Eucitharus rhenanus – POSTHUMUS 1923:

figs. 52-53

syn. ?Eucitharus rhenanus – WEILER 1942: pl. 4,

fig. 37; pl. 5, figs. 2-3

syn. Solea aff. guestfalica – WEILER 1958: pl. 3,

figs. 30-31

syn. ?Eucitharus rhenanus – ZILCH 1965: pl. 37,

fig. 22

syn. Solea guestfalica – ZILCH 1965: pl. 37, fig. 23

syn. Eucitharus belgicus GAEMERS 1972 – GAE-

MERS 1972: pl. 1, fig. 2; pl. 3, figs. 5-6

?syn. Sebastes weileri GAEMERS 1972 – GAEM-

ERS 1972: pl. 1, fig. 5; pl. 3, fig. 4

syn. Bothidarum weileri SCHWARZHANS 1974 –

SCHWARZHANS 1974: figs. 60-61; pl. 3,

fig. 13

syn. Soleidarum guestfalica – SCHWARZHANS

1974: figs. 58-59; pl. 3, fig. 16

syn. Bothidarum weileri – SCHWARZHANS 1973:

pl. 1, fig. 6

syn. Bothidarum weileri – MENZEL 1980: pl. 2,

fig. 7

syn. Bothidarum weileri – MENZEL 1983: pl. 4,

fig. 7

?syn. Scophthalmidarum sp. – MENZEL 1983: pl.1,

fig. 6

syn. Citharus belgicus – GAEMERS 1984: pl. 4,

figs. 13-14

syn. Citharus sp. – MÜLLER 1994: pl. 10, figs.

8-9

syn. Rhombocitharus rhenanus – SCHWARZ-

HANS 1994: figs. 498-506

Investigated otoliths: The lectotype (SMF P

1133a, fig. 90) and two paralectotypes (SMF P

1132, figs. 91-92) of R. rhenanus from Waldböckel-

heim, Mainz Basin, Germany, Middle Oligocene,

the neotype of Solea guestfalicus (SMF P 1425,

fig. 98) from Bünde, northern Germany, Upper

Oligocene, and the holotype of Bothidarum weileri

(SMF P 4279, fig. 96) from Moers-Schwafheim,

northern Germany, Upper Oligocene. In addition

I have investigated some 75 otoliths from various

localities in northern Germany of Upper Oli-

gocene age; figured specimens are from Söllingen

(otolith investigated by KOKEN and identified

as Percidarum varians, PMHUB Ot. 147, fig. 93),

and 3 otoliths from Ratingen near Düsseldorf (coll.

Schwarzhans, leg. Klinger and Boscheinen, figs.

94, 95, 97).

Remarks: R. rhenanus has also frequently been

described from locations outside the North Sea

Basin and from quite different stratigraphic lev-

els. All these secondary records represent differ-

ent species. The records from the Miocene of the

Paratethys (Austria) represent either Lepidorhom-

bus subtriangularis (in the sense of SCHUBERT,

1906) or Citharus lusitanicus (in the sense of WEIN-

FURTER, 1952). A record from the Upper Creta-

ceous of Austria by LIEBUS (1927) does not rep-

resent a Pleuronectiform at all but likely a perci-

form (SCHWARZHANS 1997).

Ontogeny and variability: For discussion of

ontogenetic changes see chapter discussion to the

genus.

Variability in this species is moderate. But

together with the drastic ontogenetic changes this

apparently had led in the past to the erection of

so many different species which now have to be

placed in synonymy. Major variations are seen in

the development of the posterior and postdorsal

rims, and the length-proportions of ostium and

cauda, both particularly so in juveniles. In some

instances ventral and posterior rims are some-

what undulated.

Discussion: Otoliths of R. rhenanus are more

elongate than those of R. rhomboides of the same

size. It differs from all other species known so far

in the ostium being always somewhat longer than

the cauda. It must reminded, however, the com-

parison with other species of the genus is solely

based on juveniles. R. rhenanus is the only species

from which adults are known for certain.

Distribution: Middle and Upper Oligocene of the

North Sea Basin (northern Germany, Belgium and

the Netherlands) and Middle Oligocene of the

Mainz Basin (Germany).

Fig. 99: Rhombocitharus rhomboides

(SCHWARZHANS 1973) – 10 ×

Schwarzhans: Pleuronectiformes

Rhombocitharus rhomboides

(SCHWARZHANS 1973)

Fig. 99

syn. Bothidarum rhomboides SCHWARZHANS

1973 – SCHWARZHANS 1973: pl. 1, fig. 5

syn. Citharus belgicus GAEMERS – NOLF 1976:

pl. 17, figs. 17-18

syn. Bothidarum rhomboides – SCHWARZHANS

1977: fig. 29

Investigated otoliths: The holotype (RGM

175647, fig. 99), 3 paratypes (1 coll. Schwarzhans,

2 coll. Schürmann) and one additional otolith (coll.

Geol. Landesamt of NRW), all from the shaft

Sophia Jacoba IV near Hückelhoven, northern

Germany, depth interval 55-80 m, Lower Oli-

gocene.

Ontogeny and variability: Since the few otoliths

investigated are very much of the same size anal-

yses of ontogenetic changes and variability are

not possible.

Discussion: This species was based on rather

juvenile otoliths in the order of 1.5 to 2.0 mm.

They are easily recognized by their extremely

compressed appearance and the rombohedral

outline with its strong predorsal angle. Never-

theless, the validity of this species must be re-

garded as preliminary for the time being until

larger specimens have come to light. There is

indeed a good chance for such additional mate-

rial since a newly sunk shaft at Hückelhoven has

yielded a rich Lower Oligocene fauna. However,

this material has not been picked and determined

until now.

Distribution: Lower Oligocene of northern Ger-

many and Belgium.

Rhombocitharus cauneillensis NOLF 1988

Figs. 100-101

syn. Citharus cauneillensis NOLF 1988 – NOLF

1988: pl. 14, fig. 3-4

Investigated otoliths: 3 otoliths, the holotype

(IRSNB P 4519, fig. 100) from Cauneille and the

two paratypes (one figured, IRSNB P 4520,

fig. 101) from Saint-Lon-les-Mines, all Upper

Eocene of Aquitaine Basin (France).

Discussion: The three unique type-specimens of

this species are all very small, between 1.0 and

1.5 mm. They may not have developed all perti-

nent diagnostic features at this size. Also all of

them are slightly eroded along the rims or on the

inner face. Hence the taxonomic validity of the

species at present is somewhat questionable.

R. cauneillensis is very similar to R. circularis

from the Lower Eocene of England (London Ba-

sin) and France (Aquitaine Basin). R. cauneillensis

differs from the older species in the more undu-

lating posterior rims and the relatively short cau-

da. Additional material has yet to prove, whether

these delicate differences are statistically stable

or not.

Distribution: Upper Eocene of the Aquitaine

Basin (France).

genus aff.

Rhombocitharus novaezeelandiae n.sp.

Fig. 102

Name: After New Zealand, from where this spe-

cies has been obtained.

Holotype (and unique specimen): Fig. 102, NZGS.

Type locality: Awamoa Creek, Otago, New Zea-

land South Island.

Figs. 100-101: Rhombocitharus ccauneillensis (NOLF 1988) – 25 ×

100b

101

100a

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Age: Altonian, Lower Miocene.

Diagnosis: Elongate otolith with shallow ven-

tral and dorsal rims and pointed posterior tip.

Inner face rather convex in vertical direction.

Cauda narrower than ostium, not much shorter.

Description: Outline: Otolith small, about 2 mm

long and elongate. Dorsal and ventral rims shal-

low, dorsal rim with rounded pre- and postdorsal

angles; anterior tip somewhat pointed, posterior

tip more sharply pointed. Otolith rather thickset.

Inner face: Moderately convex in horizontal

direction and more strongly convex in vertical

direction. Sulcus moderately long and wide, rath-

er shallow. Ostium wider than cauda, but not

much longer, with pseudoostial opening. Cauda

straight, terminating at some distance from the

posterior tip of the otolith. Colliculi well separat-

ed. Dorsal and ventral depressions shallow, not

completely fused around the caudal tip.

Other views: Rims moderately sharp to thick-

set, smooth. Outer face rather flat, smooth.

Discussion: The genus Rhombocitharus so far has

only been reported from the European Tertiary.

This record from New Zealand is only tentative-

ly placed into the genus and may very well rep-

resent yet another fossil genus of Citharidae. Out-

line and habitus of the otolith does show some

remarkable differences to the European species.

The single holotype is a rather small speci-

men and is probably from a subadult fish. Nev-

ertheless, it is very characteristic and thus war-

rants the establishment of a new species.

7.4 Brachypleuridae

Genera: The family Brachypleuridae as defined

here contains two genera – Brachypleura and Lep-

idoblepharon.

Definition and relationship: When HUBBS

(1945) erected the new family Citharidae he in-

cluded the three left eyed genera Citharus, Cith-

aroides and Paracitharus as Citharinae (see chap-

ter 7.3 – Citharidae in this treatise) and the two

right eyed genera Brachypleura and Lepidoblepharon

as Brachypleurinae. The three former genera had

been removed from the Bothidae and the two

latter from the Pleuronectidae of NORMAN’s

classification.

In his detailed analysis of the above genera

HUBBS discussed at length the primitive charac-

ters shared with Psettodidae (presence of a spine

in the pelvic fin and wide separation of gill-mem-

branes) and the various more derived characters

shared with Bothidae and Pleuronectidae. He

defined one character as exclusive to Citharidae

s.l., that is the position of the vent on the eyed

side. However, he also noted that Brachypleura

(and possibly Lepidoblepharon as well) differ in

several aspects from the left eyed genera.

Otoliths of Brachypleura and Lepidoblepharon

indeed strongly suggest that the two genera may

not be as closely related to the Citharidae s.s.

(Citharinae of HUBBS) as previously assumed.

They are characterized by a number of unique

features which distinguish them from the left eyed

citharids: the strongly reduced sulcus opening,

the good separation of ostium and cauda (at least

in left sided otoliths) the latter being slightly short-

er than the ostium but of about equal width and

with a rounded tip. Otoliths of Brachypleura as

the more advanced genus are additionally char-

acterized by the ventral expansion of the collum

(see chapter 6.1; incipient in Lepidoblepharon), the

reduced rostrum and the presence of a strong

predorsal lobe.

In conclusion, it is my recommendation to remove

Brachypleura and Lepidoblepharon from the Cith-

aridae and place them in a family of their own.

Lepidoblepharon is the more plesiomorphic in this

family and its otolith outline bears some resem-

blance to citharids, indicating nevertheless some

Fig. 102: genus aff. Rhombocitharus novaezeelandiae

n.sp. – 15 ×

Schwarzhans: Pleuronectiformes

relationship of the two families. Relationship of

the Brachypleuridae to “higher” flatfishes, how-

ever, remains obscure. Resemblance with certain

Soleidae is probably superficial and due to con-

vergent evolution. Also, the possible relationship

with Pleuronectidae suggested by their dextral

body-orientation and the reduced sulcus opening

in otoliths does not seem very convincing (al-

though Lepidoblepharon otoliths resemble those of

the Poecilopsettinae to some degree). Most likely,

Brachypleuridae represent a separate specialized

offshot from the main pleuronectoid lineage at

approximately the citharid to scophthalmid level

in the cladogram of LAUDER & LIEM (1983).

Ontogeny: Available otoliths range in size from

1.5 to 3.0 mm. Although the smallest specimens

are more rounded in outline they already seem to

have developed all important and diagnostically

valid features.

Distribution: Brachypleura is known from a sin-

gle recent species in the Indo-West-Pacific (India,

Indonesian Archipelago and Philippines), a fos-

sil species from the Lower Oligocene of France

and a second fossil species tentatively attributed

to this genus from the Upper Eocene of Java, thus

indicating the antiquity of the family and its two

genera. The monospecific Lepidoblepharon is

known from very few specimens from Indonesia,

northern Australia and Japan.

Lepidoblepharon WEBER 1913

Type-species: Lepidoblepharon ophthalmolepis WE-

BER 1913

Diagnosis: Moderately thickset, compressed oto-

liths, almost circular in shape except for the some-

what pointed anterior tip. Dorsal and ventral rims

regularly curving, without prominent angles,

anterior tip blunt, somewhat pointed at the ros-

trum, posterior tip broadly rounded; index l:h

1.15-1.2. Otolith size at least 3 mm.

Sulcus shallow, short, anteriorly closed and

posteriorly terminating at some distance from the

posterior tip of the otolith. Ostium slightly long-

er than cauda, not wider. Cauda with a rounded

termination. Colliculi well developed and sepa-

rated (in left hand otoliths; nearly fused in right

hand otoliths). Collum slightly enlarged ventral-

ly. Dorsal and ventral depressions well developed,

wide and deep but not completely fused behind

cauda to form circumsulcal depression.

Inner face relatively flat; outer face slightly

convex, smooth. All rims rather sharp.

Measurements:

l:h h:t ol:cl oh:ch con.o

ophthalmolepis (l) 1.20 3.5 1.25 1.0 3.2

ophthalmolepis (r) 1.15 1.55

Side dimorphism: Side dimorphism in this ge-

nus seems to be quite well developed. In left hand

otoliths the sulcus is much wider than in right

hand otoliths and the colliculi are well separated,

whereas in right hand otoliths they are almost

completely fused. Also right hand otoliths seem

to be more compressed than left hand otoliths.

Discussion: Of the two genera of the family

Brachypleuridae, Lepidoblepharon no doubt is the

one with the more plesiomorphic otolith pattern.

This is most apparent in the outline of the oto-

liths with the lack of the predorsal projection and

the somewhat pointed rostrum. In this respect

Lepidoblepharon resembles Citharid otoliths. On

the other hand the sulcus with its short cauda

terminating at some distance from the posterior

tip of the otolith and its ovale, rounded collicu-

lum separates Lepidoblepharon from the Cithari-

dae. This apomorphic character it shares with

Brachypleura.

Species and distribution: The single species

L. ophthalmolepis has been caught very rarely in

the Arafura Sea (Indonesia) in about 300 to 400 m

depth and off Japan and northern Australia. A

possible second species from off Queensland,

Australia, kept in the AMS collection (AMS

I.23999-003, as Lepidoblepharon? sp.) was also in-

vestigated but its otoliths were found to be dis-

solved by formalin.

Lepidoblepharon ophthalmolepis WEBER 1913

Figs. 103-104

Investigated otoliths: 2 otoliths (left and right

side), 200 km NW of Port Hedland, West Aus-

tralia, from 400 m depth, AMS I.22822-022.

Distribution: Very rare in deeper water from

southern Japan to Indonesia and NW-Australia.

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Brachypleura GÜNTHER 1862

Type-species: Brachypleura novaezeelandiae GÜN-

THER 1862

syn. Laiopteryx WEBER 1913 (type-species: Brach-

ypleura xanthosticta ALCOCK = Brachypleura

novaezeelandiae)

Diagnosis: Thickset, compressed otoliths, almost

circular in shape except for the very pronounced

predorsal lobe. Dorsal rim irregular, sometimes

with postdorsal angle which is situated far back

along the dorsal rim, ventral rim deeply and reg-

ularly curving, anterior tip blunt, posterior tip

broadly rounded or with obtuse angle; index l:h

1.0-1.1. Otolith size reaching just slightly over

3 mm.

Sulcus shallow, relatively narrow, short, ante-

riorly closed and posteriorly terminating at some

distance from the posterior tip of the otolith.

Ostium slightly longer and wider than cauda.

Ostium connected with anterior tip of otolith by

faint ostial channel. Colliculi well developed and

separated. Collum expanded ventrally, not filled

with a colliculum. Dorsal and ventral depressions

well developed but not completely fused behind

cauda to form circumsulcal depression, running

at considerable distance from the sulcus.

Inner face relatively flat; outer face slightly

convex, smooth. All rims thickset except for the

thin dorsal rim and smooth.

Measurements (ab.=about):

l:h h:t ol:cl oh:ch con.i

novaezeelandiae (l) 1.00-1.10 ab. 3.0 1.15-1.40 1.0-1.4 ab. 3.5

novaezeelandiae (r) 1.55

† pentagonalis (l) 1.10-1.15 ab. 3.0 0.85-1.10 1.0-1.2 ab. 3.0

† pentagonalis (r) 1.70-1.90

† xenosulcis 1.10-1.20 2.5-3.0 1.50-1.95 1.1-1.3 ab. 4.0

Side dimorphism: The only character seeming-

ly affected by side dimorphism is the proportions

of the sulcus. In left hand otoliths the cauda is

comparatively longer and the ostium shorter than

in otoliths of the right side. This finds its expres-

sion in the index ol:cl. It is most strongly devel-

oped in the fossil B. pentagonalis. However, in the

second fossil species – genus aff. Brachypleura

xenosulcis – even a mild degree of asymmetry is

missing.

Discussion: Brachypleura is characterized by two

very specialized features – the predorsal projec-

tion and the ventrally widened collum. In this

respect it clearly differs from the second genus of

the family – Lepidoblepharon (see respective en-

try). Although the otolith pattern of Brachypleura

definitely is more apomorphic in character, its

fossil record since Upper Eocene indicates a long

separation of the two genera.

Species and distribution: One recent species –

B. novaezeelandiae – from the Indo-West-Pacific on

the lower shelf (50 to 100 m), one fossil species –

Figs. 103-104: Lepidoblepharon ophthalmolepis WEBER 1913 – 15 ×

103d

103c

103b

103a

104

Schwarzhans: Pleuronectiformes

B. pentagonalis – from the Lower Oligocene of

France (Aquitaine Basin) and a second fossil spe-

cies tentatively placed in this genus – genus aff.

B. xenosulcis – from the Upper Eocene of Java.

Brachypleura novaezeelandiae

GÜNTHER 1862

Figs. 105-110

syn. Brachypleura xanthosticta ALCOCK 1889

Investigated otoliths: 9 otoliths, 3 otoliths (2 left

side and 1 right side, figs. 105-107) from the Arafu-

ra Sea, 2 ZMH Ot. 3.1.1994.1-2 (leg. BMNH

90.2.26.144-5) and 1 BMNH 90.2.26.144-5, 2 oto-

liths (left side) from the Ganjam coast, India (iden-

tified as B. xanthosticta), 1 ZMH Ot. 3.1.1994.3 (leg.

BMNH 90.11.28.41-2) and 1 BMNH 90.11.28.41-2,

4 otoliths (left side, figs. 108-110) without loca-

tion, ZMH Ot. 3.1.1994.4-7 (leg. ZMUC).

Ontogeny and variability: Ontogenetic changes

and variability is very limited in the specimens

investigated. The smallest specimen investigated

(fig. 110) is somewhat more gently rounded in

outline and shows a less well developed predor-

sal lobe.

Discussion: The fossil B. pentagonalis differs from

the recent species only in the less prominently

developed predorsal projection and the poorly

Figs. 105-110: Brachypleura novaezeelandiae GÜNTHER 1862 – 15 ×

106

105a

105b

107

105c

110

109

108

Piscium Catalogus, Part Otolithi piscium, Vol. 2

developed ventral enlargement of the collum.

Distribution: In the Indo-West-Pacific (India,

Indonesian Archipelago and Philippines) on the

lower shelf (50 to 100 m). The type-specimens

were recorded to have been obtained from New

Zealand (hence the etymology). NORMAN (1934),

however, doubted the correctness of the type lo-

cality. So far, no additional specimens have been

obtained from New Zealandian waters.

Brachypleura pentagonalis (STEURBAUT 1984)

Figs. 111-114

syn. genus Pleuronectidarum pentagonalis STEUR-

BAUT 1984 – STEURBAUT 1984: pl. 35,

figs. 1-6

Investigated otoliths: 4 otoliths, the holotype

(IRSNB P 4248, fig. 112) and 3 paratypes (IRSNB,

figs. 111, 113, 114) from the Lower Oligocene of

d’Yrieu, Aquitaine Basin (France).

Ontogeny and variability: Like in B. novaezee-

landiae ontogenetic changes and variability is very

limited in this species, smaller specimens seem-

ingly being somewhat more rounded in outline.

Discussion: B. pentagonalis is a typical represent-

ative of the genus Brachypleura, differing from

the recent B. novaezeelandiae merely in the less

prominently developed predorsal projection and

the lack of a ventrally enlarged collum. The latter

character seemingly is a fairly recent achievement

in Brachypleura. Otherwise, the fossil species from

the Lower Oligocene proves the antiquity of the

genus and the family.

Distribution: Lower Oligocene of France (Aqui-

taine Basin).

genus aff. Brachypleura xenosulcis n.sp.

Figs. 115-117

syn. genus Bothidarum sp. – NOLF & BAJPAI

1992: pl. 6, fig. 6-8

Name: xenos (gr.) = strange and sulcus (from

Otolith terminology), referring to the sulcus

morphology, which is somewhat atypical for the

genus Brachypleura.

Holotype: Fig. 115, IRSNB P 5967.

Type locality: River outcrops about 4 km NW of

Nanggulan, Java, Indonesia.

Age: Nanggulan Formation, Early Bartonian

Figs. 111-114: Brachypleura pentagonalis (STEURBAUT 1984) – 15 ×

106

112a

112b

114

113

112c

Schwarzhans: Pleuronectiformes

(NP16 Zone), Upper Eocene.

Paratypes: 2 otoliths, topo- and stratitypic, IRSNB

P 5968 and IRSNB P 5969 (fig. 116-117).

Diagnosis: Compressed, small otoliths with al-

most circular outline. Predorsal projection feeble,

posterior tip obtuse. Ostium 1 { to nearly 2 times

as long as cauda, slightly widened ventrally near

junction with cauda. Cauda slightly narrower

than ostium and slightly curved. Circumsulcal

depression incomplete.

Description: Outline: Otoliths small (less than

2 mm), with a compressed, nearly circular out-

line. Dorsal rim highest anteriorly at the relative

weekly developed predorsal projection; anterior

and posterior tips obtuse; ventral rim deeply and

regularly curving. Otoliths moderately thickset.

Inner face: Moderately convex and rather

smooth. Sulcus short, narrow, with slightly su-

pramedian position, not much deepened. Ostium

about 1 { to 2 times as long as cauda, somewhat

widened, particularly ventrally in the area close

to junction with cauda; ostial opening reduced,

terminating at some distance from the anterior

rim of the otolith. Cauda somewhat narrowed,

slightly curving and slightly deepened, terminat-

ing at considerable distance from the posterior

tip of the otolith. Separation of colliculi rather

indistinct. Dorsal and ventral depressions well

developed, but not connected around caudal tip

of sulcus.

Other views: Rims are moderately sharp and

rather smooth. Outer face smooth, not as strong-

ly convex as inner face.

Side dimorphism: Not apparent.

Ontogeny: The size of the three species ranges

from 1.0 to 1.5 mm. The smallest specimen

(fig. 117) is much more rounded in outline than

the two larger ones, resulting in a more general-

ized appearance. The degree of allometric ontoge-

netic changes observed in the few specimens in-

dicates that the two larger specimens are more

less morphologically mature, i.e. rather represent

a small species than juveniles.

Discussion: genus aff. Brachypleura xenosulcis is

quite unmistakable by the characters given in the

diagnosis. It resembles other Brachypleura species

in the outline, the reduced sulcus opening and

the incomplete circumsulcal depression. It dif-

fers in the curved cauda, which may be regarded

as a plesiomorphic character. Because of this, its

placement in the genus Brachypleura must there-

fore be regarded as preliminary. It is quite possible

that genus aff. Brachypleura xenosulcis represents

an extinct fossil genus of the Brachypleuridae.

7.5 Scophthalmidae

Genera: Scophthalmus, Lepidorhombus, Zeugopterus

and Phrynorhombus.

Definition and relationship: Scophthalmidae are

left eyed flatfishes. They were first mentioned by

NORMAN (1934) as a subfamily (Scophthalmi-

nae) of the Bothidae and then became elevated to

family ranking by HUBBS (1945). The following

Figs. 115-117: genus aff. Brachypleura xenosulcis n.sp. – 25 ×

115a

115b

115c

116a

116b

116c

117

Piscium Catalogus, Part Otolithi piscium, Vol. 2

discussion is based on the analyses of HUBBS.

Scophthalmidae are distinguished from Bothidae

and Citharidae by the elongate pelvic fin bases.

The gill-membranes are separated as in citharids,

but not as widely; in bothids and pleuronectids

they are united. From citharids (and brachypleu-

rids, which are right eyed) they are further dis-

tinguished by the loss of the spine in the pelvic

fin. This character, which scophthalmids share

with bothids and pleuronectids, was regarded as

an important synapomorphic character of the

three families in LAUDER & LIEM’s phylogenet-

ic analysis (1983). They placed Scophthalmidae

in their cladogram between Citharidae (plesio-

morphic outgroup) and Bothidae and Pleuronec-

tidae (apomorphic ingroup).

With otoliths alone it is difficult to define the

limits of this small family since they exhibit quite

a morphological variation. This finds its expres-

sion in three genus groups, based on otoliths, that

I define as follows – Scophthalmus Group, Lepido-

rhombus Group and Zeugopterus Group. The Scoph-

thalmus and Zeugopterus Groups bear more re-

semblance to each other than either do to the

Lepidorhombus Group. The otoliths of the two

former groups may be regarded as more plesio-

morphic. They are characterized by a virtual lack

of side dimorphism in otoliths, an outline that

roughly resembles that seen in the otoliths of ci-

tharids, and an ostium which is slightly enlarged

in width. These features and the distinct opening

of the ostium which is evident in all Scophthalm-

idae are regarded as plesiomorphic. Lepidorhom-

bus otoliths on the other hand show a more elon-

gate shape with a less distinctive outline, and are

also characterized by an extreme side dimor-

phism.

Two apomorphic features are found in all

scophthalmid otoliths. One is the nearly complete

circumsulcal area which goes in hand with a rel-

atively wide separation of the caudal tip from the

rear end of the otolith. The other is the ratio ol:cl

(ranging between 1.3 and 2.2, except for Zeugopte-

rus where it can approach nearly 1.0) which re-

flects an early stage in the reduction of the length

of the cauda. Those two characters represent an

early stage in the development of the otolith

morphology seen “in maturity” in the Bothidae

and Pleuronectidae.

In conclusion, otoliths of the scophthalmid gen-

era do not contradict their being classified in one

family – Scophthalmidae although they exhibit

rather divergent morphological patterns. They

also in principal support the phylogenetic con-

cept proposed by LAUDER & LIEM.

Distribution: The four genera of the Scophthal-

midae are restricted to the temperate North At-

lantic, the Mediterranean and the Black Sea, in

both recent and fossil records.

7.5.1 Scophthalmus Group

Genera: One genus – Scophthalmus – with three

recent species from the temperate North Atlan-

tic, the Mediterranean and the Black Sea. In ad-

dition there is one undescribed fossil species re-

corded from the Middle Miocene of southern

Poland (Paratethys). It is the only group of the

family recorded from the coasts of North Amer-

ica.

Definition and relationship: Otoliths of the

Scophthalmus Group seem to represent the most

plesiomorphic in this family. They are thin, com-

pressed in outline with a distinct predorsal an-

gle. They resemble in shape somewhat Citharids.

The sulcus is clearly opening anteriorly. The os-

tium is slightly to considerably longer than the

cauda and also slightly wider. The cauda is gen-

tly curved over its entire length and terminates at

some distance from the posterior rim of the oto-

lith. The circumsulcal depression is shallow, but

more or less complete.

Otoliths of the Zeugopterus Group are quite

similar merely looking like “dwarfed” specimens

of Scophthalmus. Otoliths of the Lepidorhombus

Group in contrary differ in several aspects (see

respective entry).

Scophthalmus RAFINESQUE 1810

Type-species: Pleuronectes rhombus LINNAEUS

1758

syn. Rhombus [non COSTA 1776] WALBAUM

1792 (type-species: Pleuronectes rhombus)

syn. Rhomboides GOLDFUSS 1820 (type-species:

Pleuronectes rhombus)

syn. Psetta CUVIER 1817 (type-species: Pleu-

ronectes maximus)

syn. Lophopsetta GILL 1862 (type-species: Pleu-

ronectes maculatus MITCHILL 1814 = Scoph-

thalmus aquosus)

Schwarzhans: Pleuronectiformes

Diagnosis: Thin, compressed otoliths; ventral

rim deeply and regularly curving, deepest slight-

ly anterior of the middle, dorsal rim with prom-

inent predorsal angle and indistinct postdorsal

angle situated far backwards close to the posteri-

or rim, posterior tip blunt or with indistinct ob-

tuse angle, anterior rim with very short rostrum,

but without excisura; index l:h 1.2 to 1.4. Otolith

size up to 14 mm, but usually smaller than 10 mm.

Ostium slightly wider than cauda and slight-

ly to considerably longer, anteriorly open, rather

shallow. Cauda straight to very gently curving

over the whole length, terminating at some dis-

tance from the posterior rim of the otolith. Dorsal

and ventral depressions shallow, often indistinct,

more or less connected around caudal tip to form

a circumsulcal depression.

Inner face slightly convex; outer face slightly

concave, smooth to slightly ornamented. Rims

sharp, often crenulated or irregularly undulat-

ing.

Measurements:

l:h h:t ol:cl oh:ch con.i

rhombus 1.25-1.45 4.0-4.5 1.75-2.0 1.2-1.3 about 3.5

maximus 1.30-1.60 4.0-4.5 1.35-1.75 1.1-1.3 3.0-3.5

aquosus 1.35 4.0 1.30 1.1 about 3.5

Side dimorphism: Not apparent or else hidden

by the relatively wide intraspecific variability.

Ontogeny and variability: CHAINE (1936) has

figured large series of S. rhombus and S. maximus.

From his figures it appears that ontogenetic

changes are not very significant. Even small spec-

imens in the range of 3 to 4 mm are diagnostical-

ly valid. The smallest otolith in my collection,

however, which is about 1.5 mm long, has not

developed all pertinent diagnostic features.

Variability to the contrary can be quite signif-

icant. In particular details of the outline and length

to height proportions are apt to variations.

Discussion: See discussion in entry to group.

Species and distribution: Three recent species –

S. rhombus in the Mediterranean, Black Sea and

the NE-Atlantic from northernmost Morocco to

southern Norway, S. maximus with the same dis-

tribution pattern but also occurring of Iceland,

and S. aquosus from the Atlantic coast of North

America from Casco Bay to South Carolina. In

addition there is a single juvenile fossil record

from the Middle Miocene of southern Poland

(Paratethys) described by RADWANSKA (1992)

as Scophthalmus sp. (fig. 155, pl. 37, figs. 8-10) (see

fig. 122).

Scophthalmus maximus (LINNAEUS 1758)

Figs. 118-121

syn. Pleuronectes turbot LACEPEDE 1802

syn. Pleuronectes tuberculatus SHAW 1803

syn. Pleuronectes cyclops DONOVAN 1806

syn. Pleuronectes maeoticus PALLAS 1814 (subspe-

cies)

syn. Rhombus aculeatus GOTTSCHE 1835

syn. Rhombus stellosus BENNETT 1835

syn. Scophthalmus ponticus NINNI 1932

Investigated otoliths: 6 otoliths, 2 (right side,

fig. 121) from off Portugal, south of Lisboa, one

otolith ZMH Ot. 3.1.1994.8 (leg BMNH 94.3.29.6-

7), the other BMNH 94.3.29.6-7, 4 (left and right

side, figs. 118-120), North Sea, ZMH Ot. 2.1.1995.5-

8 (coll. Schwarzhans).

Ontogeny and variability: See entry to genus. A

large series of otoliths from this species has been

figured by CHAINE (1936).

Discussion: S. maximus differs from the parallelly

occurring S. rhombus in the comparatively longer

cauda and in being slightly more elongate.

S.aquosus shows similar sulcus proportions but

has a much less developed predorsal angle.

Distribution: Mediterranean, Black Sea, and NE-

Atlantic from southern Norway to northernmost

Morocco and from Iceland.

Scophthalmus rhombus (LINNAEUS 1758)

Fig. 123

syn. Pleuronectes cristatus LICHTENSTEIN 1801

syn. Pleuronectes laevis TURTON 1802

syn. Rhombus barbatus RISSO 1826

syn. Pleuronectes lioderma NARDO 1827

syn. Platessa pavonina COSTA 1847

Investigated otoliths: 1 otolith (right side) from

off Plymouth, England, BMNH 1988.10.11.18-23.

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ontogeny and variability: See entry to genus. A

large series of otoliths has been figured by

CHAINE (1936).

Discussion: Otoliths of S. rhombus are character-

ized by their relatively short cauda.

Distribution: Mediterranean, Black Sea, and NE-

Atlantic from southern Norway to northernmost

Morocco.

Scophthalmus aquosus (MITCHILL 1815)

Fig. 124

syn. Pleuronectes maculatus MITCHILL 1814 (pre-

occupied)

Investigated otoliths: 1 otolith (right side) from

the coast of Connecticut, USA, BMNH 79.10.9.66.

Ontogeny and variability: No data.

Discussion: Otoliths of S. aquosus are recognized

by the combination of the relatively long cauda

which is almost as wide as the ostium and the

moderate predorsal angle. They resembles clos-

est otoliths of S. maximus.

Distribution: NW-Atlantic, coasts of North

America from Casco Bay to South Carolina.

7.5.2 Lepidorhombus Group

Genera: One genus – Lepidorhombus – with two

recent species in the NE-Atlantic and the western

Mediterranean and three fossil species from the

Upper Oligocene to the Upper Miocene of the

North Sea Basin and the Paratethys. One of the

two recent species – L. whiffiagonis – has also been

recorded as fossil from the Pliocene of the North

Sea Basin.

Fig. 122: Scophthalmus sp. – 10 ×

Figs. 118-121: Sophthalmus maximus (LINNAEUS 1758) – 10 ×

118

119b

119a

121

120

Schwarzhans: Pleuronectiformes

Definition and relationship: Otoliths of the ge-

nus Lepidorhombus differ in a number of aspects

from those of the other genera in the family Scoph-

thalmidae. For one thing they are the only genus

with a pronounced side dimorphism in otoliths.

Furthermore they are characterized by a more

gently curved outline, a more massive rostrum,

the more strongly reduced size of the cauda which

is oval in shape, and the rather strongly devel-

oped and complete circumsulcal depression.

From otolith analysis it seems that the Lepi-

dorhombus Group occupies a somewhat separat-

ed position within the Scophthalmidae. Judging

from otoliths alone Lepidorhombus could also be

placed in the Bothidae, for instance close to the

Paralichthys Group.

Lepidorhombus GÜNTHER 1862

Type-species: Pleuronectes megastoma DONOVAN

1804 (syn. L. whiffiagonis)

Diagnosis: Thin, roundish to moderately elon-

gate otoliths; ventral rim shallow to moderately

deep, regularly curving, dorsal rim gently curv-

ing in left sided otoliths, with prominent post-

dorsal angle in right sided otoliths, predorsal

angle indistinct, posterior tip rounded or point-

ed, anterior rim with relatively strong massive

rostrum, but without excisura; index l:h 1.1 to

1.85. Otolith size up to 10 mm, but usually small-

er than 7 mm. Specimens from about 3 to 4 mm

seem to be morphologically mature.

Ostium slightly wider than cauda but consid-

erably longer, anteriorly open, moderately deep.

Cauda short, oval in shape, terminating at some

distance from the posterior rim of the otolith.

Dorsal and ventral depressions deep, wide, well

connected around caudal tip to form a circum-

sulcal depression.

Inner face almost flat; outer face flat to slight-

ly concave, smooth, sometimes with postdorsal

ridge. Rims sharp, smooth or slightly and ir-

regularly undulating.

Measurements

(ab.=about):

l:h h:t ol:cl oh:ch con.i

whiffiagonis (left) 1.60-1.70 3.5 2.1-2.2 1.0-1.2 5-6

whiffiagonis (right) 1.55-1.60 4.5 1.5-1.6 7-8

boscii (left) 1.35-1.50 ab. 5.0 2.0-2.2 0.9-1.1 5-6

boscii (right) 1.30-1.45 ab. 5.0 1.65-1.8 6-7

†subtriangularis (l) 1.65-1.85 2.5-3.5 1.6-1.8 1.1-1.35 4.5

†subtriangularis (r) 1.55-1.80 3.5 1.25-1.4 1.0-1.1 6.5

†angulosus (left) 1.45-1.55 3.5-4.0 1.5-2.2 1.1-1.35 4-5

†klockenhoffi (l) 1.10-1.25 1.6-2.0 1.1-1.2 nm

Fig. 123: Scophthalmus rhombus (LINNAEUS 1758) – 10 ×

Fig. 124: Scophthalmus aquosus (MITCHILL 1815) – 10 ×

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Side dimorphism: Otoliths of the genus Lepido-

rhombus exhibit a remarkable degree of side di-

morphism, one of the largest to be seen in Pleu-

ronectiforms. The features are:

Sulcus shape and depth: Otoliths of the eyed

side show a much deeper sulcus with a propor-

tionally shorter cauda.

Separation of colliculi: Otoliths of the blind

side usually show well separated colliculi, where-

as in otoliths of the eyed side they are almost

completely fused.

Otolith proportions: Otoliths of the eyed side

are often more elongate than those of the blind

side.

Outline of otolith: Otoliths of the blind side

show a rather gently curved dorsal rim, whereas

those of the eyed side exhibit a strong postdorsal

angle. Also, in otoliths of the eyed side the rostrum

is more massive. Rims of otoliths of the eyed side

are usually smoother than those of the blind side.

Circumsulcal depression: In otoliths of the

eyed side the circumsulcal depression is less well

limited towards the cauda and usually shallower

than in otoliths of the blind side. Also, otoliths of

the eyed side often show multiple radial ridges

and furrows crossing the rear part of the circum-

sulcal depression.

Curvature of the inner face: The inner faces of

otoliths of the eyed side are usually more convex

than those of the blind side, particularly so in the

vertical direction.

It must be noted, however, that the degree of

side dimorphism in otoliths is somewhat varia-

ble from species to species. It is strongest in

L. whiffiagonis and L. subtriangularis, but less well

developed in L. boscii.

Ontogeny and variability: CHAINE (1936) has

figured a large set of otoliths from the two recent

species. From his figures it appears that ontoge-

netic changes of otoliths down to about 4 to 5 mm

in length are rather inconspicuous. They have

often developed a ridge or knob situated post-

dorsally on the outer face. In specimens smaller

than 3 to 4 mm this character usually is not de-

veloped.

Intraspecific variability, on the other side, is

relatively strong. Both otolith and sulcus propor-

tions may be affected to a certain extend as well

as details of the outline and its ornamentation.

Discussion: See entry to Lepidorhombus Group.

Species and distribution: Two recent species –

L. whiffiagonis in the western Mediterranean and

Figs. 125-128: Lepidorhombus whiffiagonis (WALBAUM 1792) – 6 ×

125a

125b

126a

126c

126b

127

128

Schwarzhans: Pleuronectiformes

in the NE-Atlantic found on the deep shelf down

to 400 m, and L. boscii with the same distribution

pattern but found in depths down to 800 m.

L. whiffiagonis is also known as fossil from the

Pliocene of Belgium. In addition there are three

fossil species – L. subtriangularis from the Upper

Oligocene to Middle Miocene of the North Sea

Basin and the Middle Miocene of Austria and

Poland (Paratethys), L. angulosus from the Lower

and Middle Miocene of the North Sea Basin, and

L. klockenhoffi from the Upper Miocene of the

North Sea Basin.

Lepidorhombus whiffiagonis

(WALBAUM 1792)

Figs. 125-128, 14

syn. Pleuronectes megastoma DONOVAN 1804

syn. Pleuronectes pseudopalus PENNANT 1812

syn. Pleuronectes (Rhombus) cardina CUVIER 1829

syn. Lepidorhombus megastoma borealis KYLE 1913

syn. Lepidorhombus whiffiagonis – otoliths: GAE-

MERS & SCHWARZHANS 1973: pl. 3,

fig. 38; pl. 10, fig. 7

Investigated otoliths: 4 otoliths (2 left side and

2 right side) from the North Sea, ZMH Ot.

5.1.1994.1-4 (coll. Schwarzhans).

Ontogeny and variability: See entry to genus. A

large series of otoliths has been figured by

CHAINE (1936).

Side dimorphism: L. whiffiagonis is one of the

species of this genus with a very strongly devel-

oped side dimorphism (see entry to genus).

Discussion: Otoliths of L. whiffiagonis are readi-

ly distinguished from those of the other recent

species – L. boscii – in being more elongate. The

ventral rim is curving more shallow. Otoliths of

the eyed side show a much stronger postdorsal

angle than those of L. boscii.

Distribution: Western and Central Mediterrane-

an and NE-Atlantic from southern Norway and

Iceland to southern Morocco (Cape Bojador).

L. whiffiagonis is also known as fossil from the

Lower Pliocene of Belgium.

Lepidorhombus boscii (RISSO 1810)

Figs. 129-131

Investigated otoliths: 3 otoliths, 2 (right and left

side, figs. 129-130) from Banjules, France, West-

ern Mediterranean, BMNH 1976.7.30.270-4, 1 oto-

lith (right side, fig. 131) from off Malta, 25°44’N/

15°07’E, ZMH Ot. 5.1.1994.5 (leg. ZMUC 853446).

Ontogeny and variability: See entry to genus.

A large series of otoliths has been figured by

CHAINE (1936).

Side dimorphism: Otolith asymmetry is less

strongly developed in L. boscii than in other spe-

cies of the genus. Sulcus proportions are practi-

cally identical between otoliths from the eyed and

from the blind sides. Also the development of the

postdorsal angle is much less differential than

for instance in L. whiffiagonis.

Discussion: See L. whiffiagonis.

Figs. 129-131: Lepidorhombus boscii (RISSO 1810) – 6 ×

130

129

131c

131a

131b

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Distribution: Western Mediterranean and NE-

Atlantic from Scotland to southern Morocco (Cape

Bojador). A fossil record of this species from the

Pliocene of Belgium (NOLF, 1978) is based on a

very eroded otolith and therefore may not be

regarded as valid.

Lepidorhombus subtriangularis

HEINRICH 1970

Figs. 132-142

syn. Rhombus rhenanus KOKEN – SCHUBERT

1906: pl. 6, fig. 15

syn. Lepidorhombus subtriangularis HEINRICH

1970 – HEINRICH 1970: fig. 1

syn. Solea subglabra SCHUBERT – SMIGIELSKA

1973: pl. 5, fig. 9

syn. Lepidorhombus angulosus NOLF 1976 (pars) –

NOLF 1976: pl. 17, fig. 15 (non fig. 16 = hol-

otype)

syn. Lepidorhombus angulosus NOLF – RADWAN-

SKA 1992: fig. 154; pl. 37, figs. 1-7

syn. Scophthalmus sp. – RADWANSKA 1992

(part): fig. 155; pl. 37, figs. 9-10 (non pl. 37,

fig. 8 – Scophthalmus sp.)

syn. Lepidorhombus aff. subtriangularis – MÜLLER

1994: pl. 10, fig. 5

syn. Lepidorhombus subtriangularis – SCHWARZ-

HANS 1994: figs. 517-521

Investigated otoliths: 24 otoliths, 6 otoliths from

the Upper Oligocene of various locations in north-

ern Germany (2 figured from Ratingen, coll Klin-

ger, left side, figs. 133-134), 1 otolith (left side,

fig. 132) from well Wetten near Goch, northern

Germany, Reinbekian, Middle Miocene, coll.

Wienrich, and as L. aff. subtriangularis 2 otoliths

(right side) from Bad Vöslau, Austria, Badenian,

Middle Miocene, GBW 1906/1/69 (originally

identified by SCHUBERT, 1906 as Rhombus rhen-

anus) and 14 otoliths (figs. 135-142) from Rybni-

ca, Poland, Badenian, Middle Miocene, ZPalUW-

RaR 418-426, 427-429 (coll. Radwanska).

Ontogeny and variability: The largest otolith of

this species known so far is the well preserved

holotype of HEINRICH (1970), which is about

5.5 mm long. This specimen and the one of

fig. 132, which is about 4 mm long seemingly

represent a mature morphological stage. The

smaller ones are lacking the horizontal ridge or

knob situated postdorsally on the outer face.

A feature of considerable variability is the

postdorsal angle in left sided otoliths. It is strongly

developed in the well preserved holotype of

Figs. 132-134: Lepidorhombus subtriangularis HEINRICH 1970 – 15 ×

132c

134b

132b

132a

133

134a

Schwarzhans: Pleuronectiformes

HEINRICH (1970) and the specimen figured as a

paratype of L. angulosus by NOLF (1976). Figures

by RADWANSKA (1992) and those otoliths fig-

ured here show both strong and feeble postdor-

sal angles. However, the otoliths from the Mid-

dle Miocene of Austria and Poland in general are

Figs. 135-142: Lepidorhombus aff. subtriangularis HEINRICH 1970 – 15 ×

135

136a

136b

137a

138

137b

139

140

141

142

Piscium Catalogus, Part Otolithi piscium, Vol. 2

a little more slender and do not show the post-

dorsal thickening of the outer face, which seems

to be typical at least for the larger specimens from

the North Sea Basin. Eventually, once more ma-

terial has become available, they might be regard-

ed as a different species altogether. For the time

being I recommend to leave them as L. aff. subtri-

angularis (figs. 135-142).

Side dimorphism: Like L. whiffiagonis, L. subtri-

angularis too exhibits a rather strong degree of

side dimorphism. This can be seen best in a series

of both left and right sided otoliths from Poland

(figs. 135-142; see also RADWANSKA, 1992).

Specimens from the Tertiary of the North Sea

Basin so far have almost exclusively been left sid-

ed.

Discussion: L. subtriangularis resembles in all

aspects the recent L. whiffiagonis. Differences if any

are the slightly more elongate appearance and

the comparatively longer cauda (index ol:cl, see

list to genus). Larger otoliths of L. subtriangularis

seem to be more thickset than those of

L. whiffiagonis due to the strong postcentral ridge

or knob on the outer face (apparent only in spec-

imens from the North Sea Basin). Anyway, both

species apparently are closely related, i.e. L. sub-

triangularis may represent the ancestor of L. whif-

fiagonis.

Figs. 143-146: Lepidorhombus angulosus NOLF 1976 – 15 ×

143a

143b

143c

144b

144a

146

145a

145b

Schwarzhans: Pleuronectiformes

Distribution: Upper Oligocene to Middle Mi-

ocene of the North Sea Basin and as L. aff. subtri-

angularis (figs. 135-142) also from the Middle

Miocene of the northern Paratethys (Austria and

Poland). It may additionally be expected in the

Middle Miocene of the Atlantic European Basins,

although not proven as yet despite extensive re-

search (STEURBAUT, 1984).

Lepidorhombus angulosus NOLF 1976

Figs. 143-146

syn. Lepidorhombus angulosus NOLF 1976 (pars) –

NOLF 1976: pl. 17, fig. 16 (holotype), non

fig. 15 (L. subtriangularis)

syn. Lepidorhombus angulosus – MENZEL 1986:

pl. 9, fig. 3

Investigated otoliths: 5 otoliths, 1 otolith (left

side, fig. 143), well Lüllingen near Goch, north-

ern Germany, Hemmoorian to Reinbekian, Low-

er to Middel Miocene, coll. Wienrich, 1 otolith

(left side, fig. 145), well UWO 36 Hellwege near

Ahaus (129-132 m), northern Germany, Hemmoo-

rian, Lower Miocene, NLB 11732 (ident. and leg.

Menzel), 1 otolith (right side, fig. 144), well Wet-

ten near Goch, northern Germany, Reinbekian,

Middle Miocene, coll. Wienrich, 1 otolith (left side)

from Dingden near Bocholt, northern Germany,

Reinbekian, Middle Miocene, coll. Schwarzhans,

1 small otolith (right side, fig. 146) from quarry

Sunder at Twistringen near Bremen, Reinbekian,

Middle Miocene, coll. Schwarzhans.

Ontogeny and variability: The few specimens

known so far do not allow analysis of ontogenet-

ic changes or variability.

Side dimorphism: Although known from very

few specimens so far, it seems that side dimor-

phism is not very strongly developed in this spe-

cies, comparable may be to L. boscii.

Discussion: L. angulosus differs from the paral-

lelly occurring L. subtriangularis in being more

compressed and more thinset. In these respects it

resembles closely the recent L. boscii (also in the

degree of side dimorphism, see above). Otoliths

of L. boscii seem to be even more compressed and

usually exhibit a shorter cauda (see index ol:cl in

listing to genus). However, morphological differ-

ences are so small that a very close relationship is

being postulated. This indicates that the lineage

L. angulosus – L. boscii has been separated from

the lineage L. subtriangularis – L. whiffiagonis for a

considerable time span.

Distribution: Lower (?) and Middle Miocene of

the North Sea Basin (Belgium and northern Ger-

many).

Lepidorhombus klockenhoffi

GAEMERS & SCHWARZHANS 1982

Fig. 147-150

syn. Lepidorhombus klockenhoffi GAEMERS &

SCHWARZHANS 1982 – GAEMERS &

SCHWARZHANS 1982: pl. 8, figs. 6-11

Investigated otoliths: 17 otoliths (all type-mate-

rial) from the Isle of Sylt, northern Germany,

Syltian, Upper Miocene, figured specimens are

fig. 147 (holotype, left side, RGM 176 674) and

figs. 148-150 (paratypes, 2 left and 1 right side,

RGM 176 684).

Figs. 147-150: Lepidorhombus klockenhoffi GAEMERS & SCHWARZHANS 1982 – 10 ×

147

148

149

150

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ontogeny and variability: The largest otolith

known to date is about 3.6 mm long and may not

be fully mature.

Variability is particularly evident in the de-

velopment of the postdorsal and the posterior

rims. Usually, the postdorsal angle is pronounced

and the posterior rim blunt, but some otoliths

show a weak postdorsal rim and a somewhat

angular to pointed posterior tip (not figured). It

looks as if the postdorsal angle has moved down-

ward.

Side dimorphism: Practically all right handed

otoliths are poorly preserved and therefore only

one specimen is figured. It seems that right hand-

ed otoliths are more roundish in shape with fee-

ble postdorsal angles and a weak rostrum.

Discussion: L. klockenhoffi is easily recognized by

its extreme compressed appearance. It apparent-

ly represents a third yet extinct lineage within

the genus Lepidorhombus.

Distribution: Known exclusively from the type

locality.

7.5.3 Zeugopterus Group

Genera: Two genera – Zeugopterus – with one

recent species from the North Sea and one fossil

species from the Upper Oligocene of the North

Sea Basin, and – Phrynorhombus – with two recent

species from the European coast of the Atlantic

and the Western Mediterranean and one fossil

species from the Miocene of the North Sea Basin.

Definition and relationship: Otoliths of the

Zeugopterus Group in many aspects resemble

those of Scophthalmus, single genus of the Scoph-

thalmus Group. In fact, they somehow look like

dwarfed Scophthalmus otoliths.

Otoliths of the Zeugopterus Group are rela-

tively small in size like the fishes themselves, too.

The ostium is just slightly longer and wider than

the cauda. The cauda sometimes shows an incip-

ient and very gently curvature over its whole

length. The circumsulcal depression is complete

in both genera, although sometimes quite feeble.

I assume that the Zeugopterus Group repre-

sents a specialized offshot from near the Scoph-

thalmus Group.

Zeugopterus GOTTSCHE 1835

Type-species: Pleuronectes hirtus ABILDGAARD

1789 (syn. Z. punctatus)

Diagnosis: Moderately thin, compressed otoliths;

ventral rim regularly curving, deepest at about

the middle, dorsal rim with rounded predorsal

angle and usually prominent postdorsal angle

situated far backwards close to the posterior rim,

posterior tip with obtuse angle, anterior rim with

short, sometimes massive rostrum, but without

excisura; index l:h 1.25 to 1.65. Otolith size not

exceeding 2.5 mm, morphologically mature from

about 1.5 mm.

Ostium markedly wider than cauda and only

slightly longer, anteriorly open, moderately deep.

Cauda straight to very gently curving over the

whole length, terminating relatively close to the

posterior rim of the otolith. Dorsal and ventral

Figs. 151-153: Zeugopterus punctatus (BLOCH 1787) – 15 ×

152

153a

153b

151b

151c

151a

100

Schwarzhans: Pleuronectiformes

depressions shallow, often indistinct, but connect-

ed around caudal tip to form a circumsulcal de-

pression.

Inner face slightly convex, particularly so in

the vertical direction; outer face slightly concave,

smooth. Rims sharp, sometimes irregularly un-

dulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

punctatus 1.25-1.40 3.0 1.05-1.2 1.2-1.7 3.5-4.0

†rosenthalensis 1.40-1.55 3.0 1.15-1.35 1.1-1.5 3.5-4.0

Side dimorphism: Not apparent.

Ontogeny and variability: Ontogenetic changes

do not seem to be very drastic. Small otoliths of

1.5 mm or less just look more generalized and

“smoothed” in outline.

Variability to the contrary is considerable. It

affects aspects of the outline, and proportions of

otolith and sulcus to some extent.

Discussion: Fishes and otoliths of Zeugopterus

grow to larger sizes than those of Phrynorhombus.

This is probably the reason why they look less

“reduced” in otolith morphology. Outline of the

otolith, proportions of the sulcus and shape of

the cauda still resembles Scophthalmus very much.

In Phrynorhombus for instance the gentle curva-

ture of the cauda is completely reduced, the cau-

da ovally shaped.

Species and distribution: One recent species –

Z. punctatus – in the North Sea, and one fossil

species – Z. rosenthalensis – from the Upper Oli-

gocene of northern Germany.

Zeugopterus punctatus (BLOCH 1787)

Figs. 151-153

syn. Pleuronectes hirtus ABILDGAARD 1789

syn. Zeugopterus papillosus BROOK 1886

Investigated otoliths: 3 otoliths, (2 right, 1 left

side) off Plymouth, ZMH Ot. 5.1.1994.6 (leg.

BMNH 1988.10.11.27-29) and BMNH 1988.

10.11.27-29.

Ontogeny and variability: See entry to genus.

Discussion: Z. punctatus differs from the fossil

Z. rosenthalensis in being more compressed and

showing a more angularly developed dorsal rim.

Also in Z. rosenthalensis the cauda is completely

straight.

Distribution: North Sea from southern Norway

thru the channel to the Bay of Biscay mainly on

stones and rocks in the algal zone. In addition

there is a possible record from the Pliocene of

Belgium by NOLF (1978; as Zeugopterus cf. punc-

tatus). His drawing, however, does not allow for

a reliable identification.

Zeugopterus rosenthalensis (WEILER 1942)

Figs. 154-157

syn. Bothus rosenthalensis WEILER 1942 – WEILER

1942: pl. 5, fig. 1

syn. Bothidarum rosenthalensis – SCHWARZ-

HANS 1974: fig. 68

syn. Zeugopterus rosenthalensis – SCHWARZ-

HANS 1994: figs. 512-516

Figs. 154-157: Zeugopterus rosenthalensis (WEILER 1942) – 15 ×

154c

154a

154b

155a

155b

157

156

101

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Investigated otoliths: 17 otoliths from various

locations from the Upper Oligocene of northern

Germany, figured specimens, 1 otolith (left side,

fig. ) shaft Sophia Jacoba 8 near Hückelhoven

(279-282.5 m), coll. von der Hocht, 1 otolith (left

side, fig. ) from well in Krefeld-Uerdingen, coll.

Schwarzhans, 2 otoliths (1 left side, 1 right side,

figs.) from well near Willich, coll. von der Hocht.

Variability: Variations concern details of the out-

line and proportions of otolith and sulcus.

Discussion: Z. rosenthalensis differs from the re-

cent Z. punctatus in being more elongate, show-

ing a more regularly rounded dorsal rim and a

rather massive rostrum. Also the cauda is com-

pletely straight. In these aspects, particularly so

the shape of the cauda, Z. rosenthalensis also re-

sembles otoliths of Phrynorhombus. In fact, this

species seems like being morphologically inter-

mediate between the two closely related genera.

Distribution: Upper Oligocene of northern Ger-

many (North Sea Basin).

Phrynorhombus GÜNTHER 1862

Type-species: Rhombus unimaculatus RISSO 1826

(syn. P. regius)

Diagnosis: Moderately thin, compressed otoliths;

ventral rim deeply and regularly curving, deep-

est at about the middle, dorsal rim irregular some-

times with pre- and postdorsal angles or medio-

dorsal angle, posterior tip blunt or with obtuse

angle, anterior rim without or with very short

rostrum, but without excisura; index l:h 1.15 to

1.45. Otolith size up to 2.5 mm, but usually smaller

than 2 mm.

Ostium wider and longer than cauda, anteri-

orly open, moderately deep. Cauda straight, oval

in shape, terminating at some distance from the

posterior rim of the otolith. Dorsal and ventral

depressions marked, well connected around cau-

dal tip to form a circumsulcal depression. Some-

times dorsal and/or ventral depression are

crossed by radial furrows in otoliths of both sides.

The dorsal and ventral cristae of the cauda are

often prominent, sometimes tubercular.

Inner face flat to slightly convex; outer face

flat to slightly concave, smooth. Rims moderate-

ly sharp, sometimes irregularly undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

norvegicus 1.15-1.25 about 3.0 1.2-1.75 1.1-1.6 3.0-4.0

†medius 1.30-1.45 3.0-3.7 1.05-1.35 1.0-1.2 5.4-5.7

Side dimorphism: Side dimorphism in this ge-

nus is masked by the very high degree of the

intraspecific variability. It seems that otoliths of

the eyed side are just slightly more elongate.

Ontogeny and variability: Practically all Phry-

norhombus otoliths known so far are between 1.5

and 2.5 mm large. Within this size distribution

ontogenetic changes are not apparent.

Variability within the species of this genus is

extremely high. There is almost no character

which remains uninfluenced. Outline, propor-

tions of otolith and sulcus vary to quite some

extent. Diagnosis of species will depend on large

otolith series and even then distinction of them

will not always be possible.

Discussion: Otoliths of the genus Phrynorhom-

bus are very small and look like “dwarfed” Scoph-

thalmus otoliths in many ways. In fact, they are

even smaller than the otoliths of the related ge-

nus Zeugopterus. Morphologically, they are also

more generalized, for instance as far the sulcus is

concerned. This makes recognition of isolated

otoliths of Phrynorhombus very difficult. The low

diagnostic value of Phrynorhombus otoliths will

make it even difficult at times to safely distin-

guish them from juvenile otoliths of some other

Pleuronectiform genus.

Apart from the difficulties in recognizing

Phrynorhombus otoliths they certainly resemble

Zeugopterus otoliths, and in my opinion both gen-

era are closely related.

Species and distribution: Phrynorhombus con-

tains two recent species – P. norvegicus from the

North Sea, northern Norway to the Bay of Biscay

and Iceland and P. regius from the British Isles to

Gibraltar and in the western Mediterranean. There

is one fossil record – P. medius – from the Lower

to Upper Miocene of northern Germany (North

Sea Basin). A second fossil record – P. bassolii – by

SCHUBERT (1906) from the Middle Miocene of

Austria (Paratethys) does not represent a Pleu-

ronectiform (see chapter 4.2).

102

Schwarzhans: Pleuronectiformes

Phrynorhombus norvegicus (GÜNTHER 1862)

Figs. 158-162

Investigated otoliths: 7 otoliths (4 left and 3 right

side) from SW-England, IRSNB (coll. Nolf).

Ontogeny and variability: See entry to genus.

The 5 otoliths figured have been selected to give

an impression of the variability occurring in this

species.

Discussion: Otoliths of P. norvegicus differ from

those of the other recent species – P. regius – in

the absence of a distinct rostrum.

Distribution: Iceland, Norway, British Isles and

France south to the Bay of Biscay on rocky bot-

toms between 10 and 180 m.

Phrynorhombus regius (BONNATERRE 1788)

syn. Pleuronectes calimanda LACEPEDE 1802

syn. Pleuronectes uniocellatus NARDO 1824

syn. Rhombus unimaculatus RISSO 1826

syn. Rhombus setiger MICHAHELLAS 1829

syn. Pleuronectes saxatilis NARDO 1847

Discussion: I have not investigated otoliths of

this species. CHAINE (1936) has figured a number

of otoliths from both recent Phrynorhombus spe-

cies. Unfortunately, his figures are very small and

do not allow for a detailed analysis. Anyhow, it

seems that otoliths of P. regius differ from those

of P. norvegicus in exhibiting a more pronounced

rostrum.

Distribution: From the British Isles to Gibraltar

and in the western Mediterranean on rocky bot-

toms between 10 and 180 m.

Phrynorhombus medius WEILER 1958

Figs. 163-165

syn. Phrynorhombus medius WEILER 1958 –

WEILER 1958: pl. 3, fig. 16

?syn. Phrynorhombus medius – GAEMERS &

SCHWARZHANS 1982: pl. 2, fig. 6

syn. Bothidarum obliquus MENZEL 1986 – MEN-

ZEL 1986: pl. 8, fig. 10; pl. 10, fig. 6

Investigated otoliths: 5 otoliths, the holotype of

Bothidarum obliquus (right side, fig. 165) from well

UE 45 Wistedt near Zeven, Lower Saxonia, Hem-

moorian, Lower Miocene, NLB 11733 (leg. Men-

zel), 2 otoliths (right side, fig. 163, 164) from well

Oxlund (105-128 m), Schleswig-Holstein, Hem-

moorian, Lower Miocene, coll. Martini (leg. An-

derson), 2 otoliths (left side, one figured in GAE-

MERS & SCHWARZHANS, 1982), Morsum Kliff,

Isle of Sylt, Syltian, Upper Miocene, RGM 176

688-689.

Ontogeny and variability: Variability like in all

Phrynorhombus otoliths is considerable, mostly

concerning proportions of otolith and sulcus. The

otolith of fig. 164 is remarkable for its considera-

Figs. 158-162: Phrynorhombus norvegicus (GÜNTHER 1862) – 15 ×

158

159

161a

161b

160a

162b

162a

160b

160c

103

Piscium Catalogus, Part Otolithi piscium, Vol. 2

bly more compressed and roundish outline. It

could possibly represent a distinct species, but

since it is a unique specimen of a genus known

for its high variability it could also represent just

an extreme variation.

Discussion: Otoliths of P. medius seem to grow

to slightly larger sizes than those of the two re-

cent species. In general their otoliths are slightly

more elongate and the ostium is usually not as

much longer as the cauda (see index ol:cl in list-

ing to genus). The latter character also distinguish-

es them from parallelly occurring juveniles of

Lepidorhombus spp.

Distribution: Lower to Upper Miocene of north-

ern Germany.

7.6 Bothidae

Genera: The Bothidae as recognized here con-

tains some 39 living genera. In alphabetical order

they are: Achiropsetta, Ancylopsetta, Arnoglossus,

Asterorhombus, Bothus, Caulopsetta, Cephalopsetta,

Chascanopsetta, Citharichthys, Crossorhombus, Cyclo-

psetta, Engyophrys, Engyprosopon, Etropus, Gas-

tropsetta, Grammatobothus, Hippoglossina, Japonol-

aeops, Kamoharaia, Laeops, Lioglossina, Lophonectes,

Mancopsetta, Monolene, Neolaeops, Orthopsetta,

Parabothus, Paralichthys, Pelecanichthys, Perissias,

Psettina, Pseudorhombus, Syacium, Taeniopsetta, Tar-

phops, Thysanopsetta, Tosarhombus, Trichopsetta,

Xystreurys.

Definition and relationship: In NORMAN

(1934) the Bothidae were understood as an as-

semblage of all left eyed Pleuronectoidei, includ-

ing of what are now the Citharidae and the Scoph-

thalmidae. He distinguished three subfamilies –

Paralichthyinae, Bothinae and Scophthalminae –

based on the nature of the pelvic fin bases and

presence or absence of transverse apophyses in

the caudal vertebrae. HUBBS (1945) separated

Scophthalmidae and Citharidae from Bothidae

as distinct families (see entry to Citharidae and

Scophthalmidae). In some recent literature Paral-

ichthyinae have also been distinguished as a sep-

arate family (see NELSON 1984). EVSEENKO

(1984) and GON & HEEMSTRA (1990) placed the

two genera Achiropsetta and Mancopsetta in a fam-

ily of their own – the Achiropsettidae. Compar-

ing the characters listed by NORMAN there are

indeed some features, for instance in the genus

Mancopsetta, which do distinguish them from

other bothids (see also HENSLEY & AHLSTROM

1984). These are the median position of the vent

in front of the anal fin, the position of the tip of

the dorsal fin behind the posterior nostril of the

blind side (both presumably plesiomorphic char-

acters), the loss of pectoral fins (an apomorphic

character) and the pattern of the hypurals. – These

alternative views raise the question whether the

Bothidae in its wider sense may not represent a

polyphyletic assemblage, even after extraction of

the Citharidae and the Scophthalmidae. Otolith

analyses might offer support for a solution but

the available evidence is rather feeble and I have

therefore selected to retain Bothidae as a single

family in the sense of HUBBS (1945) with two

subfamilies (Bothinae and Paralichthyinae) in the

sense of HENSLEY & AHLSTROM (1984). The

only exception from this is the genus Tephrinectes

which I have removed from the Bothidae and

placed into a category of uncertain relationship

close to Psettodidae and Citharidae solely on the

163c

163a

163b

165a

164a

164b

165b

165c

Figs. 163-165: Phrynorhombus medius WEILER 1958 – 15 ×

104

Schwarzhans: Pleuronectiformes

base of otolith analysis (see entry to Tephrinectes

Group, chapters 7.2. and 7.2.1).

Otoliths of Bothidae exhibit a wide range of

morphological patterns that do not allow for a

simple definition as a family. In general terms the

cauda is already quite reduced in length, width

and morphology (i.e. it is straight with a rounded

tip). The circumsulcal depression is complete or

nearly complete around the posterior tip of the

cauda. These are the main distinctions from the

more plesiomorphic families such as Psettodidae,

Citharidae or Scophthalmidae, although some-

what intermediate forms particularly towards the

pattern seen in the Scopthalmidae do exist. The

ostium can be clearly open anteriorly even with

development of an excisura, but more commonly

it is closed sometimes terminating at a consider-

able distance from the anterior rim of the otolith.

In this respect bothid and pleuronectid otoliths

are often quite similar, although in Pleuronecti-

nae the reduction of the sulcus opening is usually

more strongly developed. In fact placement of

otoliths in either the one or other family often

depends very much on correlation at the generic

level. Then, however, the taxonomic problem can

be solved quite reliably in most instances. The

degree of side dimorphism in bothid otoliths is

not as great as in pleuronectids and in most in-

stances is limited to details of the outline of the

otolith.

As stated before I have informally employed

a division of the family Bothidae into two sub-

families – the Paralichthyinae and the Bothinae.

In addition, it is possible, with the help of otolith

analysis, to define at least 11 genus-groups ex-

hibiting specific otolith morphologies. These are

the Paralichthys, Pseudorhombus, Syacium, Citharich-

thys, Bothus, Arnoglossus, Monolene-Laeops, Engy-

prosopon, Thysanopsetta, Chascanopsetta and Man-

copsetta Groups. The first four (Paralichthys, Pseu-

dorhombus, Syacium and Citharichthys Groups)

probably form a related cluster to which the sub-

family status of Paralichthyinae may be attribut-

ed. This group is more or less equivalent to the

Paralichthyinae of NORMAN (1934) and the Par-

alichthyidae of HENSLEY & AHLSTROM (1984).

Their otoliths are relatively large, delicately or-

namented, with a moderately to strongly reduced

ostial opening. Furthermore, the Syacium and

Citharichthys Groups exhibit a number of derived,

presumably autapomorphic characters which

makes their recognition relatively easy (see re-

spective entries). HENSLEY & AHLSTROM

(1984) recognized two generic groups, the Pseu-

dorhombus and Cyclopsetta Groups (the latter in-

cluding the Syacium and Citharichthys otolith

groups). Likewise, the genera of the Bothus Group

and the Arnoglossus, Monolene-Laeops and Engy-

prosopon Groups may be interrelated constituting

the Bothinae of NORMAN (1934) (except for Tri-

chopsetta, Engyophrys, Perissias and Monolene

which he placed in the Paralichthyinae; in this

latter respect the concept of the Bothidae of HENS-

LEY & AHLSTROM, 1984, agrees better with the

otolith findings). The otoliths of these four both-

ine groups are relatively small in size, compact,

often with a nearly rectangular outline with little

ornamentation and with a full or only slightly

reduced ostial opening. However, most of these

characters except for the ostial opening must be

regarded as somehow “reduced”. The remaining

three groups – Thysanopsetta, Chascanopsetta and

Mancopsetta Groups – stand somewhat apart from

the rest of the Bothidae and, together with Tephri-

nectes, in my opinion are the first candidates for

exclusion from the Bothidae proper (for details

see respective entries and HENSLEY & AHL-

STROM, 1984). For convenience only they are here

kept in the subfamily Bothinae.

In conclusion, the definition of the Bothidae by

means of otolith morphology is not very satisfac-

tory. Nevertheless, using otoliths, two large

groups can be outlined which more or less reflect

NORMAN’s classification of the two subfamilies

Paralichthyinae and Bothinae and even more

closely HENSLEY & AHLSTROM’s classification

of the two families Paralichthyidae and Bothi-

dae. In addition there are three small generic

groups which stand somewhat isolated from the

rest, and one genus – Tephrinectes – which clearly

should be removed from the family.

Distribution: Bothidae are widely distributed

throughout the shallow seas of the world oceans.

They are most common and specious in the trop-

ical and subtropical latitudes. The two genera of

the Mancopsetta Group are the only flatfishes oc-

curring in Subantarctic and Antarctic waters.

Some genera are caught in relatively deep water

(Gastropsetta, Mancopsetta, Perissias, Thysanopset-

ta, Trichopsetta and certain species of Arnoglossus)

on the lower continental shelf. The genera of the

Chascanopsetta Group are amongst the deepest

living flatfishes, usually caught on the continen-

tal rises.

105

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Paralichthyinae

7.6.1 Paralichthys Group

Genera: In this group I have placed 6 genera –

Ancylopsetta, Gastropsetta, Hippoglossina, Xystr-

eurys, Lioglossina and Paralichthys. This group is

almost entirely from the new world, the excep-

tion being a single species of the genus Paralich-

thys (P. olivaceus from the coasts of China and

Japan). Apart from two recent Paralichthys spe-

cies recorded as fossils from the Pliocene of Cal-

ifornia and Japan, there are no fossil records of

this group.

Definition and relationship: Otoliths of the Par-

alichthys Group probably represent the most ple-

siomorphic condition within the Bothidae. Oto-

liths are moderately large, rather elongate and

often nicely ornamented. The rostrum is always

well developed. The sulcus opening is pseudoos-

tial. The ostium is usually much longer than the

cauda and sometimes slightly wider too. The

cauda is short, straight and with a rounded ter-

mination. This “reduced” character constitutes the

main difference from otoliths of the Scophthalmi-

dae, which are otherwise quite similar. The cir-

cumsulcal depression is usually relatively feeble,

but in most instances well connected behind the

cauda. The degree of side dimorphism is very

low, usually confined to minor differences in the

outline of the otolith, if it is detectable at all. As

a general rule the diagnostically critical size of

otoliths of this group is reached between 3 and

4 mm. Total size rarely exceeding 8 mm.

Morphologically, otoliths of the Paralichthys

Group are somewhat intermediate between those

of the Scophthalmidae and the more advanced

bothid groups. Of the latter the Pseudorhombus,

Syacium and Citharichthys seem to be most close-

ly related. In ichthyological literature the two

genera Paralichthys and Pseudorhombus are com-

monly regarded as very closely related (see

NORMAN, 1934 and GINSBURG, 1952), to an

extant that differentiation of the two genera be-

comes a very delicate task. Otoliths on the other

hand are quite easily differentiated, although the

close relationship may not be questioned. The

reason for separating Pseudorhombus (and related

genera) from the Paralichthys Group is principal-

ly based on the argument that their otolith anal-

ysis characterizes them as the basal morphology

from which the other paralichthin groups may

have derived (for detailed discussion see entries

to genera Paralichthys, Pseudorhombus and the

Pseudorhombus Group).

Ancylopsetta GILL 1864

Type-species: Ancylopsetta quadrocellata GILL 1864

syn. Notosema GOODE & BEAN 1883 (type-spe-

cies: Notosema dilecta)

syn. Ranularia JORDAN & EVERMANN 1898

(type-species: Ancylopsetta dendritica)

Diagnosis: Relatively thin, oval to elongate oto-

liths; ventral rim shallow and gently curving,

deepest slightly posterior of the middle, dorsal

rim with angular to rounded postdorsal angle

and indistinct predorsal angle situated at about

midventral position, posterior tip blunt or round-

ed, anterior rim with prominent rostrum, but

without excisura; index l:h 1.45 to 1.85. Otolith

size probably not much exceeding 5.5 mm.

Ostium slightly wider than cauda but consid-

erably longer, rather shallow. Index ol:cl 1.55 to

2.25. Ostial opening pseudoostial. Cauda short,

straight with rounded termination at considera-

ble distance from the posterior rim of the otolith.

Dorsal and ventral depressions shallow, often

indistinct, more or less well connected around

caudal tip to form a circumsulcal depression.

Inner face slightly convex; outer face slightly

concave, flat or slightly convex, smooth to slight-

ly ornamented. Rims sharp, smooth or slightly

crenulated to irregularly undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

dilecta 1.45 3.1 1.55 1.1 about 4.0

quadrocellata 1.80-1.85 3.7 2.25 1.1-1.2 about 4.5

cycloidea 1.70 nm 1.55 1.3 nm

microtenus 1.70 3.0 1.55 1.0 about 5.0

antillarum 1.55 2.8 1.65 1.1 about 6.0

Side dimorphism: Not apparent.

Discussion: Otoliths of the genus Ancylopsetta

are the least characteristic within this group due

to their rather smooth and regularly curved out-

line. They closely resemble Lioglossina and cer-

tain Paralichthys species.

Species and distribution: Ancylopsetta contains

7 recent species, 6 from the Atlantic coasts of

Central and southern North America – A. antilla-

106

Schwarzhans: Pleuronectiformes

rum, A. cycloidea, A. dilecta, A. kumperae,

A. microtenus and A. quadrocellata – and one from

the Pacific coast of America from California to

Panama – A. dendritica.

Ancylopsetta dilecta (GOODE & BEAN 1883)

Fig. 166

syn. Paralichthys stigmatias GOODE 1884

Investigated otoliths: 1 otolith (right side) from

off Carolina, USA (32°54’N/77°3’W), ZMH Ot.

20.3.1994.1 (leg USNM 45596).

Discussion: This is the most compressed otolith

found in all species of the Paralichthys Group with

the most regularly rounded outline. A. dilecta thus

is relatively easy to be recognized. The genus

Notosema established for this species by GOODE

& BEAN (1883) could possibly be regarded as a

subgenus of Ancylopsetta.

Distribution: Known only from the coasts of

Carolina, USA.

Ancylopsetta quadrocellata GILL 1864

Figs. 167-168

syn. Paralichthys ommatus JORDAN & GILBERT

1879

Investigated otoliths: 2 otoliths (left and right

side) from off Charleston, South Carolina, USA,

ZMH Ot. 20.3.1994.2 (leg. BMNH 1933.8.10.13)

and BMNH 1933.8.10.13.

Discussion: Otoliths of A. quadrocellata are con-

siderably more elongate than those of the other

species investigated. They do resemble Paralich-

thys species with more rounded otolith outlines

such as P. squamilentus and P. albiguttata. Both,

however, show a relatively longer cauda as do

most species of the genus Paralichthys.

Distribution: Atlantic and Gulf coasts of the

United States.

Ancylopsetta cycloidea TYLER 1959

Fig. 169

Investigated otoliths: 1 otolith (right side) from

off Tobago, BMNH 1965.6.17.1.

Discussion: The only specimen investigated is

slightly damaged ventrally, but otherwise well

preserved. It closely resembles A. quadrocellata ex-

cept for the almost entirely smooth outline and

the slightly lesser index l:h.

Distribution: Caribbean.

Figs. 167-168: Ancylopsetta quadrocellata GILL 1864 – 10 ×

167a

167c

167b

168

Fig. 166: Ancylopsetta dilecta

(GOODE & BEAN 1883) – 10 ×

107

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ancylopsetta microtenus

GUTHERZ 1966

Fig. 170

Investigated otoliths: 1 otolith (right side), para-

type, off Honduras, 16°5’N/81°7’W, BMNH

1965.6.17.6.

Discussion: Very similar to A. cycloidea but less

rounded in outline and with blunt posterior tip.

Distribution: Off Honduras.

Ancylopsetta antillarum

BERRY & GUTHERZ 1965

Fig. 171

Investigated otoliths: 1 otolith (right side), para-

type, NW Bahamas, 25°3’N/79°3’W, BMNH

1965.6.17.3.

Discussion: Rather compressed, massive otolith

with relatively flat ventral rim and pronounced

dorsal rim.

Distribution: Off Bahamas.

Gastropsetta BEAN 1895

Type-species: Gastropsetta frontalis BEAN 1895

Diagnosis: Thin, fragile, moderately elongate

otolith; ventral rim shallow and gently curving,

dorsal rim more strongly bent with a pronounced,

broadly rounded medioventral angle and a rela-

tively feeble postdorsal angle, posterior tip rath-

er blunt, anterior rim with massive, not very

prominent rostrum and without excisura; index

l:h 1.55. Otolith size about 3 mm.

Ostium slightly wider than cauda but consid-

erably longer, rather shallow. Index ol:cl 2.9. Os-

tial opening pseudoostial. Cauda short, straight

with rounded termination at considerable dis-

tance from the posterior rim of the otolith. Dorsal

and ventral depressions very shallow to indis-

tinct, but well connected around caudal tip to

form a circumsulcal depression.

Inner face slightly convex; outer face slightly

concave, smooth to slightly ornamented. Rims

sharp, slightly undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

frontalis 1.55 4.3 2.9 1.5 4.8

Side dimorphism: Not known.

Discussion: NORMAN (1934) regarded this ge-

nus as closely related to Ancylopsetta. This inter-

pretation is supported by the habitus of the oto-

lith in particular the very short cauda. In fact, it

is the shortest cauda to be found within the Par-

alichthys Group. Gastropsetta may be regarded as

a specialized off-branch from Ancylopsetta.

NIELSEN (1963) described the new genus Dor-

sopsetta from off Peru, which he regarded as close-

ly related to Gastropsetta (otoliths of that genus

are not known).

Species and distribution: Gastropsetta is a mono-

typic genus. Its only species G. frontalis has been

caught very rarely in relatively deep water off

Florida, USA. NORMAN (1934) has recorded only

three catches of this species.

Fig. 170: Ancylopsetta microtenus GUTHERZ 1966

– 10 ×

Fig. 169: Ancylopsetta cycloidea TYLER 1959 – 10x

108

Schwarzhans: Pleuronectiformes

Gastropsetta frontalis BEAN 1895

Fig. 172

Investigated otoliths: 1 otolith (left side) from

off dry Tortugas, Florida, USA, BMNH 1933.

10.12.125.

Discussion: See entry to genus (monotypic ge-

nus).

Distribution: In relatively deep water off Flori-

da, USA.

[Dorsopsetta NIELSEN 1963]

Type-species: Dorsopsetta norma NIELSEN 1963

Remarks: Dorsopsetta was erected as a monospe-

cific genus by NIELSEN, known only from two

relatively small subadults caught off Peru. The

paratype in the ZMUC collection (P 853116) has

been x-rayed in order to find out whether oto-

liths are still preserved. Unfortunately, they were

not, probably dissolved by formalin.

NIELSEN regarded Dorsopsetta als related to

Gastropsetta. In the meantime D. norma has been

reviewed by HEIDEN & PEREZ (1993). They re-

garded NIELSEN’s type-specimens as a synonym

of Cyclopsetta querna (see respective entry).

Hippoglossina STEINDACHNER 1876

Type-species: Hippoglossina macrops STEIN-

DACHNER 1876

Diagnosis: Relatively thin, elongate otoliths;

ventral rim shallow and gently curving, deepest

slightly posterior of the middle, dorsal rim like-

wise shallow with rounded pre- and postdorsal

angles, posterior tip obtuse or rounded, anterior

rim with moderately strong and blunt rostrum,

but without excisura; index l:h 1.70 to 1.85. Oto-

lith size probably not much exceeding 7 mm.

Ostium slightly wider than cauda but not very

much longer, slightly deepened. Index ol:cl 1.4 to

1.8. Ostial opening pseudoostial. Cauda not very

short, straight to just very slightly curving, with

rounded termination at considerable distance

from the posterior rim of the otolith. Dorsal and

ventral depressions rather well developed, but

connection around caudal tip often feeble or in-

distinct.

Inner face almost flat; outer face slightly con-

vex, smooth. Rims sharp, smooth or slightly and

irregularly undulating.

Measurements:

l:h h:t ol:cl oh:ch con.o

macrops (left) 1.70-1.80 3.5 1.8 1.0-1.1 about 7.0

macrops (right) 2.8 1.45 about 3.5

stomata (left) 1.80-1.85 3.4 1.4 1.1-1.2 about 5.5

stomata (right) 2.8 about 4.5

Side dimorphism: Side dimorphism in otoliths

of this genus is rather feeble or so tends to sub-

merge under the relatively high degree of varia-

bility. The latter is particularly true for the pro-

portions and outline of otoliths and sulcus. How-

Fig. 171: Ancylopsetta antillarum

BERRY & GUTHERZ 1965 – 10 ×

Fig. 172: Gastropsetta frontalis BEAN 1895 – 15 ×

109

Piscium Catalogus, Part Otolithi piscium, Vol. 2

ever, some degree of side dimorphism seems to

be stable as far as width of the sulcus (narrower

in left otoliths) and convexity of outer face (more

convex or thickset in right otoliths) is being con-

cerned.

Variability: Details of the outline of the otoliths

as well as its proportions and the proportions of

the sulcus seem to be quite variable. As a result

of this distinction of the closely related species

may not always be possible.

Discussion: Hippoglossina otoliths can be distin-

guished from other genera of the Paralichthys

Group by at least three major characters. They

show the proportionally longest cauda which in

some instances even exhibits a faint curvature.

This is supposed to be an inherited plesiomor-

phic character. Secondly, the inner face is unusu-

ally flat. Thirdly, the otoliths are quite elongate,

but this is not due to a long rostrum but the over-

all elongate shape of the otolith. The two latter

are regarded as apomorphic features.

NORMAN (1934) has related Hippoglossina to

Lioglossina and Paralichthys and also regarded

Hippoglossina as one of the most plesiomorphic

genera in his Paralichthyinae. Indeed does the

structure of the cauda exhibit a comparatively

more primitive nature, but the other characters

as listed above do not. A close relationship to

Lioglossina and Paralichthys may very well be the

case, but according to otolith analysis I would

then regard Hippoglossina as an early somewhat

specialized off-shot from the main Paralichthin

branch. GINSBURG (1952) stated that he found

Hippoglossina to be even more closely related to

Pseudorhombus. This view, however, is decidedly

contradicted by the otolith analysis (see also en-

tries to Pseudorhombus and Pseudorhombus Group).

Species and distribution: GINSBURG (1952)

mentioned four species of the genus Hippogloss-

ina, all of them restricted to the Pacific shores of

America (from California to southern Chile) –

H. bollmani, H. macrops, H. mystacium and H. sto-

mata. CHIRICHIGNO (1974) lists a fifth species

from southern Peru and Chile – H. montemaris.

Hippoglossina aff. macrops

STEINDACHNER 1876

Fig. 173

Investigated otoliths: 2 otoliths from 1 specimen

(left and right side) from the Smyth Channel,

Magellan Strait, ZMH Ot. 20.3.1994.3-4 (leg. ZMH

19958).

Remarks: These otoliths were obtained from one

of two specimens recorded by LÖNNBERG

(1907). According to GINSBERG (1952) the spe-

cific assignment of the two specimens is ques-

tionable, particularly since the origin of STEIN-

DACHNER’s holotype is unclear. NORMAN

(1934) describes the two specimens of GÜNTHER

as representing H. macrops which originated from

the same region (Magellan Strait) as the one

LÖNNBERG specimen from which I have taken

otoliths. Later (1937) he placed the two

GÜNTHER specimens in H. mystacium. In GINS-

BURG’s recommendations the two LÖNNBERG

specimens need restudy before a definite conclu-

sion about their specific allocation can be reached.

Preliminarily, I have chosen to leave the speci-

men in question and from which the otoliths have

been obtained with H. macrops, following LÖN-

NBERG’s original identifications.

Discussion: The otoliths of H. aff. macrops are

very similar to those of H. stomata. If there are

any diagnostically valid and stable differences

they are probably the more bluntly developed

posterior rim in H. aff. macrops and also its slight-

ly lesser index l:h. Anyway, the specimens inves-

tigated from H. stomata and H. aff. macrops have

been obtained at the northern and southern lim-

its of the distribution pattern of this genus and

thus sheds some light on the poor level of mor-

Fig. 173: Hippoglossina aff. macrops STEINDACHNER

1876 – fig. 173a = 15 ×; fig. 173b = 10 ×

110

Schwarzhans: Pleuronectiformes

phological differentiation to be expected from the

otoliths of its species. If I interpret GINSBERG’s

remarks correctly the same may be true as well

for other “more traditional” taxonomic methods.

Distribution: The type location of the species

given by STEINDACHNER was Mazatlan (north-

ern Mexico, Pacific coast), which falls in the

distribution range of H. stomata. NORMAN (1934)

concluded that the type locality given by STEIN-

DACHNER was almost certainly incorrect. Then

H. macrops should be distributed only along the

shores of Chile as far south as the Magellan Strait.

Hippoglossina stomata

EIGENMANN & EIGENMANN 1890

Figs. 174-176

Investigated otoliths: 4 otoliths, 3 figured (left

and right side) from off Acapulco, Pacific coast of

central Mexico, ZMH Ot. 20.3.1994.5-8 (leg. Fitch).

Variability: The two specimens figured already

show the relatively large degree of variability to

be expected within the species of this genus. Fea-

tures concerned are ornamentation of the outline

(smooth or undulating), proportions of the oto-

lith (index l:h) and development of the angles at

the dorsal rim.

Discussion: Otoliths of H. stomata are hardly to

distinguished from those of H. aff. macrops (see

respective entry).

Distribution: California, USA and Pacific coast

of Mexico.

Xystreurys JORDAN & GILBERT 1881

Type-species: Xystreurys liolepis JORDAN & GIL-

BERT 1881

syn. Verecundum JORDAN 1890 (type-species:

Verecundum rasile)

Diagnosis: Thin, elongate otoliths; ventral and

dorsal rims shallow and gently curving, dorsal

rim with indistinct and rounded pre- and post-

dorsal angles, posterior tip blunt or obtuse, ante-

rior rim with moderately pronounced rostrum,

but without excisura; index l:h 1.75 to 1.8. Otolith

size of specimens investigated about 5 mm.

Sulcus narrow. Ostium not or only slightly

wider than cauda and not very much longer, rath-

er shallow. Index ol:cl 1.45 to 1.65. Ostial opening

Figs. 174-176: Hippoglossina stomata EIGENMANN & EIGENMANN 1890 –

figs. 174, 175a, 176a = 15 ×; figs. 175b,c 176b = 10 ×

174

175c

175b

175a

176a

176b

111

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Xystreurys liolepis

JORDAN & GILBERT 1881

Figs. 177-179

Investigated otoliths: 3 otoliths from off Cali-

fornia USA, (2 left and 1 right side) ZMH Ot.

20.3.1994.10-11 (leg. BMNH 91.5.19.169-170) and

BMNH 91.5.19.169-170.

Discussion: See entry to X. rasile.

Distribution: Coast of California, USA.

Xystreurys rasile (JORDAN 1890)

Figs. 180-181

syn. Hippoglossina notata BERG 1895

syn. Xystreurys brasiliensis REGAN 1914

Investigated otoliths: 2 otoliths (right side) from

off Uruguay, ZMH Ot. 2.1.1995.9 (leg. BMNH

1935.9.11.10-11) and BMNH 1935.9.11.10-11.

Discussion: Similar to X. liolepis but without

marginal crenulation and with rather strongly

developed predorsal angle. Also the cauda is

somewhat shorter (index ol:cl).

Distribution: Coasts of Brazil, Uruguay and

Argentine.

pseudoostial. Cauda moderately short, straight

with rounded termination at considerable dis-

tance from the posterior rim of the otolith. Dorsal

and ventral depressions well marked, faintly con-

nected around caudal tip to form a circumsulcal

depression.

Inner face slightly convex; outer face slightly

concave and slightly ornamented. Rims sharp,

delicately undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

liolepis 1.75-1.80 4.8 1.45-1.65 1.0-1.1 about 6.5

rasile 1.75-1.80 4.1 1.8-1.85 1.1 about 10

Side dimorphism: Not apparent.

Variability: The variability seems to be unusual-

ly small, except for the intensity of the marginal

ornamentation observed in X. liolepis, particular-

ly so at the posterior rim.

Discussion: The otoliths of the genus Xystreurys

resemble those of Hippoglossina in outline.

Species and distribution: Two recent species,

one – X. liolepis – from southern California, USA,

the other – X. rasile – from Brazil to Argentine.

Figs. 177-179: Xystreurys liolepis JORDAN & GILBERT 1881 – 10 ×

177

178a

179

178b

178c

112

Schwarzhans: Pleuronectiformes

Lioglossina GILBERT 1891

Type-species: Lioglossina tetrophthalmus GILBERT

1891

Diagnosis: Moderately thin and moderately

elongate otoliths; ventral rim shallow and gently

curving, deepest slightly posterior of the middle,

dorsal rim relatively high and also regularly curv-

ing with faint postdorsal angle and very indis-

tinct predorsal angle, posterior tip rounded, an-

terior rim with prominent rostrum, but without

excisura; index l:h 1.55 to 1.75. Otolith size prob-

ably not exceeding much 5-6 mm.

Ostium not or only slightly wider than cauda

but considerably longer, rather shallow. Index ol:cl

1.75 to 2.9. Ostial opening pseudoostial with ten-

dency for further reduction. Cauda short, straight

with rounded termination at considerable dis-

tance from the posterior rim of the otolith. Dorsal

and ventral depressions moderate, faintly con-

nected around caudal tip to form a circumsulcal

depression.

Inner face slightly convex, more strongly so

in the vertical direction; outer face more or less

flat, slightly ornamented. Rims sharp, intensely

to very intensely ornamented.

Measurements:

l:h h:t ol:cl oh:ch con.i

tetrophthalmus (l) 1.75 3.5 2.9 1.1-1.2 about 8.0

tetrophthalmus (r) 1.65 1.8

oblongus (r) 1.55 4.3 1.75 1.0 about 9.0

Side dimorphism: Development of side dimor-

phism is relatively feeble, as seen in one of the

two species (L. tetrophthalmus). It seems that the

left otoliths have a slightly more pronounced

rostrum, which also finds its expression in the

index l:h. As a consequence the ostium is also

longer in the left otolith which account for at least

half of the unusually high index ol:cl.

Ontogeny: The otoliths examined of the two

species are still relatively small and may not have

developed all pertinent diagnostic features, al-

though it seems that at least the one from L. ob-

longus is quite characteristic (5 mm length).

Discussion: NORMAN (1934) and GINSBURG

(1952) both had Lioglossina as closely related to

Hippoglossina and Paralichthys. This is confirmed

by otoliths, although from their analysis Liogloss-

ina seems to be more closely related to Paralich-

thys than Hippoglossina. In fact, Lioglossina could

well represent a specialized off-shot from Parali-

chthys. The high dorsal rim and the tendency to

reduce the ostial opening are seen as the major

differences to Paralichthys otoliths.

NORMAN (1934) regarded Lioglossina as a

monotypic genus with L. tetrophthalmus being its

only species. GINSBURG (1952) also included

L. oblonga. I have followed his view, although the

status of investigation of otoliths from L. tetroph-

thalmus at present is not really adequate (see also

to species).

Species and distribution: Two species – L. te-

trophthalmus known from the Gulf of California

and Pacific coast of Central America (the speci-

men from which the otolith were obtained was

caught at the Pacific coast of Columbia) and

L. oblonga from the Atlantic coast of North Amer-

ica from Massachusetts to Florida.

Figs. 180-181: Xystreurys rasile (JORDAN 1890) – 10 ×

181a

180

181b

113

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Lioglossina tetrophthalmus GILBERT 1891

Figs. 182-183

Investigated otoliths: 2 otoliths from 1 specimen

(left and right side) from the Pacific coast of Co-

lumbia (3°44’N/77°32’W), SMF unreg. (1 now

ZMH Ot. 20.3.1994.9).

Discussion: Otoliths of L. tetrophthalmus are more

“Paralichthys alike” than those of the other spe-

cies of the genus – L. oblonga. The latter differs in

the more reduced ostial opening and the very

high dorsal rim with its extremely strong orna-

mentation.

Distribution: Pacific coast from California to

Middle America. The specimen figured was tak-

en from a fish caught at the Pacific coast of Co-

lumbia, which is south of the distribution limits

noted by NORMAN (1934) and GINSBURG

(1952).

Lioglossina oblonga (MITCHILL 1815)

Fig. 184

Investigated otoliths: 1 otolith (right side) from

off New Jersey, USA (40°10’N / 73°36’W), BMNH

1923.6.18.2.

Discussion: Otoliths of this species are readily

distinguished from other species in the Paralich-

thys Group by the high dorsal rim, which is very

intensely ornamented, and the reduced ostial

opening. The whole sulcus is relatively small and

narrow.

Distribution: Atlantic coast of North America

from Massachusetts to Florida.

Paralichthys GIRARD 1858

Type-species: Pleuronectes maculosus GIRARD

1856 (preoccupied) – syn. Paralichthys californicus

syn. Chaenopsetta GILL 1861 (type-species: Pleu-

ronectes dentatus – see GINSBURG 1952)

syn. Uropsetta GILL 1863 (type-species: Hippoglos-

sus californicus)

Figs. 182-183: Lioglossina tetrophthalmus GILBERT 1891 – 15 ×

Fig. 184: Lioglossina oblonga (MITCHILL 1815) – 10 ×

182a

183

182b

182a

114

Schwarzhans: Pleuronectiformes

Diagnosis: Relatively thin, moderately elongate

to elongate otoliths; ventral rim shallow and gen-

tly curving, dorsal rim variable, usually with

pronounced postdorsal and less well developed

predorsal angles, posterior tip blunt or rounded

sometimes with obtuse angle, anterior rim with

prominent to very prominent rostrum, but usual-

ly without excisura; index l:h ranging from 1.55

to 2.05. Otolith size probably not much exceed-

ing 8 mm.

Ostium usually slightly wider than cauda and

considerably longer, rather shallow. Index ol:cl

ranging from 1.45 to 2.20, rarely up to 2.85. Ostial

opening pseudoostial. Cauda short, straight with

rounded termination at considerable distance

from the posterior rim of the otolith. Dorsal and

ventral depressions usually well marked, more

or less well connected around caudal tip to form

a circumsulcal depression.

Inner face slightly to moderately convex; out-

er face slightly concave to flat, smooth to slightly

ornamented. Rims sharp, smooth or variably

ornamented.

Measurements

(ab.=about):

l:h h:t ol:cl oh:ch con.i

orbignyana 1.60 3.0 1.60-1.85 1.05-1.6 ab. 4.0

dentatus 1.55-1.65 3.2 1.65 1.1-1.2 ab. 5.5

albiguttata 1.80 3.2 1.45-2.00 1.2-1.3 ab. 5.5

squamilentus 1.75 3.2 2.00 1.25 ab. 4.3

lethostigma 1.70 3.9 1.85 1.15 ab. 5.0

tropicus 2.00 2.5 1.70 1.35 ab. 4.0

brasiliensis 1.95 3.2 1.50 1.2 ab. 4.2

californicus 1.70-1.85 3.4 2.0-2.1 1.45-1,55 ab. 6.0

adspersus 1.65 3.7 1.65-1.8 1.2-1.25 ab. 7.0

microps 1.75-1.85 3.4 1.80-1.85 1.25-1.5 ab. 8.0

olivaceus 1.85 2.9 2.2-2.3 1.1-1.2 ab. 5.0

isocles 1.55 2.7 2.4-2.85 1.05-1.25 ab. 15.0

Side dimorphism: Side dimorphism is poorly

developed in this genus and there are some spe-

cies which do not show any asymmetry at all.

Characters affected are exclusively those of the

outline of the otolith, in particular length and

expression of the rostrum, angles at the dorsal

rim and expression of the posterior rim.

Ontogeny and variability: Ontogenetic changes

can only be studied in P. californicus and P. oliva-

ceus. From this it appears that smaller specimens

exhibit a much more rounded and more general-

ized outline than larger ones and sometimes are

also more strongly ornamented along its margins,

but in a less regular fashion. It seems that the

critical size at which all pertinent characters are

being developed is of considerable importance in

this genus. It seems that in P. californicus this size

is reached with otoliths of about 5 mm of length.

In P. olivaceus that size is reached at about 6 mm.

However, this is one of the largest growing spe-

cies within the genus. There are indications from

other, smaller species that the critical size may

commonly been reached somewhere between 4

and 5 mm of length.

Variability on the other hand seems to play a

less important role in this genus once the critical

size is being reached. In general it is restricted to

details of the outline and proportions of the sul-

cus, but seemingly never reaches the amount

observed in so many other Pleuronectiform oto-

liths.

Discussion: Otoliths of the genus Paralichthys are

quite easily recognized by their typical outline

including the strongly developed rostrum and

the pattern of their sulcus. Distinction of isolated

otoliths from some of the related genera, namely

Ancylopsetta and Lioglossina, however, may not

always be easy. Otoliths of the genus Pseudorhom-

bus, which is thought to be closely related to Para-

lichthys, are readily differentiated by their strong-

ly reduced rostrum and their peculiar outline.

There are certain Pleuronectid otoliths which also

bear some basal similarity, particularly in the

Hippoglossus and the Pleuronectes-Limanda Groups.

These similarities in the overall habitus of the

otoliths are probably due to synplesiomorphies.

The Paralichthys and the Hippoglossus Groups are

thought to represent the most plesiomorphic

groups within their respective families (Bothidae

and Pleuronectidae). However, otoliths of the two

Pleuronectid groups mentioned are in most in-

stances easily recognized by their more strongly

reduced ostial opening and the much wider and

more clearly developed circumsulcal depression.

Also the colliculi are usually more deepened.

GINSBURG (1952) has proposed to subdivide

the genus Paralichthys into two subgenera, name-

ly Paralichthys and Chaenopsetta. However, his

subdivision can not be verified by otolith find-

ings. Although otolith analysis could be used to

point out certain species which may be more

closely related to each other than others, the dif-

ferentiation at this stage in my opinion is to vague-

ly to cluster them in species groups or even sub-

genera. However, the somewhat isolated posi-

tion of P. isocles is well supported by otolith

analysis. This species differs from all the others

by its quite thickset appearance, the relatively flat

115

Piscium Catalogus, Part Otolithi piscium, Vol. 2

inner face, the very short cauda and the more

strongly deepened sulcus with its tendency to

fused colliculi. GINSBURG (1952) placed this

species into the genus Pseudorhombus which

would make it the only representative of that

genus in the new world. The presence of a well

developed rostrum in my opinion still warrants

its placement in Paralichthys or may be a separate

genus close to Paralichthys.

Remarks: In a monograph dealing with the spe-

cies of genus Paralichthys GINSBERG (1952) point-

ed out the difficulties in safely distinguishing

several of them. From his list of synonymies it

appears that many species have been confused in

the past and even his excellent review is not free

of remaining open questions as to the exact no-

menclature of some species. In this light the Par-

alichthys otoliths discussed and figured in the

following must be viewed with some care. It is

possible that few specimens from which otoliths

have been obtained were misidentified. Most of

the BMNH material probably was identified by

NORMAN. Other otoliths were extracted from

fishes in the ZMH collection which most likely

still bear their original labels irrespective of

NORMAN’s and GINSBURG’s works. The iden-

tification of these otoliths may be found less re-

liable.

Species and distribution: In combining NOR-

MAN’s and GINSBURG’s works at least 17 spe-

cies of the genus Paralichthys may tentatively be

regarded as valid. They are:

Atlantic coast of America: P. aestuarius, P. albi-

guttata, P. brasiliensis, P. dentatus, P. isocles, P. letho-

stigma, P. orbignyana, P. squamilentus, P. tropicus;

Pacific coast of America: P. adspersus, P. cali-

fornicus, P. fernandezianus, P. hilgendorfi, P. microps,

P. schmitti, P. woolmani; Coasts of China and Ja-

pan: P. olivaceus.

In addition there are some doubtful species

such as P. triocellatus from the South Atlantic and

P. caeruleosticta from Juan Fernandez Island off

Chile. P. bicyclophorus from the South Atlantic was

regarded as a valid species by NORMAN but as

a synonym of P. orbignyana by GINSBURG.

P. vorax was regarded as a valid species by GINS-

BURG but as a synonym of P. brasiliensis by

NORMAN.

Several of these species have been described

by a single holotype such as P. bicyclophorus,

P. triocellatus, P. caeruleosticta, P. fernandezianus,

P.hilgendorfi and P. schmitti. The last four were all

described from the small Juan Fernandez Island

of Chile. This fact alone renders some doubt as to

the validity of so many species in such an isolat-

ed and restricted geographic situation. Of course,

otoliths of these species have not been available

for investigation.

Paralichthys orbignyana JENYNS 1842

Figs. 185-186

syn. Paralichthys patagonicus JORDAN & GOSS

1889 (according to GINSBURG, 1952)

?syn. Paralichthys bicyclophorus RIBEIRO 1915 (ac-

cording to GINSBURG, 1952)

Investigated otoliths: 2 otoliths from one speci-

men (left and right side) from off Rio Grande do

Sul, southern Brazil, ZMH Ot. 20.3.1994.12 (leg.

BMNH 85.2.3.73-74) and BMNH 85.2.3.73-74.

Side dimorphism: The right hand otolith seems

to have a slightly more pointed and elongate

rostrum.

Figs. 185-186: Paralichthys orbignyana JENYNS 1842 – 10 ×

185a

186

185b

185c

116

Schwarzhans: Pleuronectiformes

Discussion: Otoliths of P. orbignyana are quite

easily recognized by their relatively compressed

shape, which includes a deeply curved ventral

rim and a relatively short rostrum and the feeble

development of the postdorsal angle. Also the

rims are smooth without much of an ornamenta-

tion. In outline and habitus P. squamilentus and

P. albiguttata are similar, but their otoliths are more

elongate. The same is true for P. lethostigma which

also shows a shorter cauda. P. dentatus is similar-

ly compressed as P. orbignyana, but sulcus and in

particular cauda are wider and the postdorsal

angle is much more strongly developed.

Distribution: Southern Atlantic, coasts from Bra-

zil to Argentina.

Paralichthys dentatus (LINNAEUS 1766)

Figs. 187-188

syn. Pleuronectes melanogaster MITCHILL 1825

syn. Platessa ocellaris DE KAY 1842

syn. Paralichthys ophyras JORDAN & GILBERT

1883

Investigated otoliths: 2 otoliths from one speci-

men (left and right side) from off Long Island,

USA, ZMH Ot. 20.3.1994.13-14 (leg. ZMH 19971).

Side dimorphism: The right hand otolith shows

a much shorter rostrum and a more pointed pos-

terior tip.

Discussion: Otoliths of P. dentatus are rather com-

pressed. In this respect they resemble P. orbignya-

na and P. adspersus. P. orbignyana shows a more

gently curving dorsal rim and a narrower sulcus;

P. adspersus exhibits a more strongly protruding

postdorsal angle and a less convex inner face.

Distribution: Atlantic coast of North America,

from Maine to Florida.

Paralichthys albiguttata

JORDAN & GILBERT 1883

Figs. 189-190

Investigated otoliths: 2 otoliths from one speci-

men (left and right side) from of SW-Florida, USA,

ZMH Ot. 20.3.1994.15 (leg. BMNH 1930.8.6.1-2)

and BMNH 1930.8.6.1-2.

Side dimorphism: Not apparent.

Discussion: Otoliths of P. albiguttata are easily

recognized by the combination of an elongate

shape and a rather regularly curving outline with-

Figs. 187-188: Paralichthys dentatus (LINNAEUS 1766) – 10 ×

187a

187c

187b

185b

188a

117

Piscium Catalogus, Part Otolithi piscium, Vol. 2

out any prominent angles at the dorsal rim.

P. albiguttata is a relatively small species of this

genus and it is therefore assumed that this mor-

phology represents a true adult type. However,

distinction of subadult otoliths of other Paralich-

thys species may not always be easy (see also

P. squamilentus).

Distribution: South Atlantic and Gulf coast of

the United States.

Paralichthys squamilentus

JORDAN & GILBERT 1883

Fig. 191

Investigated otoliths: 1 otolith (right side) from

off Port Arkansas, Texas, USA, BMNH 1948.

8.6.1223.

Discussion: This otolith of P. squamilentus in all

respects closely resembles the one from P. albi-

guttata. Distinction of the two is almost impossi-

ble. However, as said before, certain doubts may

remain as far as the correct identification of the

species is concerned. Also P. squamilentus is known

to grow to larger sizes than P. albiguttata. There-

fore, the single specimen available from that spe-

cies may not necessarily exhibit all valid diag-

nostic features.

Distribution: South Atlantic and Gulf coast of

the United States.

Paralichthys lethostigma

JORDAN & GILBERT 1885

Figs. 192-193

Investigated otoliths: 2 otoliths, one (right side)

from of North Carolina, USA, BMNH 1923.12.

18.11.

Discussion: The otoliths of P. lethostigma proba-

bly represent subadults since this is known as

one of the largest species of the genus. Its irreg-

ular marginal crenulation indeed suggests that

not all pertinent diagnostic features are yet de-

veloped (see also to P. olivaceus). Otherwise,

P. lethostigma resembles both P. albiguttata and

P. squamilentus in general appearance. It can be

distinguished in being thinner and exhibiting a

more rounded posterior tip.

Distribution: South Atlantic and Gulf Coasts of

the United States northward to N. Carolina.

Orthopsetta GILL 1862

Type-species: Psettichthys sordidus GIRARD 1856

syn. Metoponops GILL 1864 (type-species: Meto-

ponops cooperi, syn. O. sordidus)

Diagnosis: Moderately thickset, small otoliths

with a compressed, rounded pentagonal shape;

ventral rim deeply and rather regularly curved,

with a rounded medioventral angle, dorsal rim

with pronounced predorsal projection and round-

ed postdorsal angle, predorsal projection not bend

outward, portion between postdorsal angle and

posterior tip slightly concave, posterior tip round-

ed, somewhat projecting, occupying a median to

submedian position, anterior rim bluntly round-

ed; index l:h 0.9 to 1.15. Otolith size possibly not

exceeding much 4.5 mm.

Colliculi fused, distinction of ostium and cau-

da practically completely masked. Sulcus more

or less horizontal, indistinctly “fusiform” to oval

in shape. Dorsal and ventral depressions moder-

ately deep, more or less continuously connected

around caudal tip to form a circumsulcal depres-

sion.

Inner face flat to very slightly convex, rather

smooth; outer face convex, smooth or with little

ornamentation. Rims moderately sharp, usually

smooth, sometimes slightly undulated or crenu-

lated.

Measurements:

l:h h:t ol:cl (oh:ch) con.o

stigmaeus 1.00-1.15 3.7 nm 1.2-1.4 3.7

sordidus 0.95-1.10 5.5 nm nm 3.5

fragilis 1.00 3.8 nm nm 3.5

xanthostigma 0.95-1.00 4.2 nm nm 2.8

arctifrons 0.90-1.00 4.0 nm nm 2.9

cornutus 0.90-0.95 2.9 nm 1.5-1.7 2.5

Side dimorphism: Not apparent.

Ontogeny and variability: Smaller otoliths are

usually not as extremely compressed than larger

ones. Diagnostic size may be reached with 2 to

2.5 mm. Intraspecific variability somewhat vari-

ably, but usually of moderate nature. Details and

proportions of otolith outline are the most strongly

affected parameters, but in some instances out-

line of sulcus may be affected as well.

Discussion: Otoliths of Orthopsetta may be dis-

tinguished from those of the related genus Cith-

arichthys by their more strongly reduced sulcus

morphology, the more roundish shape of the oto-

liths which are also more compressed and the

almost completely flat inner face (resulting in a

Figs. 274-275: Citharichthys macrops DRESEL 1885 – 15 ×

275

274c

274b

274a

148

Schwarzhans: Pleuronectiformes

convex outer face). For further discussion includ-

ing ichthyological differentiation of the two gen-

era see entry to Citharichthys. Distinction from

Etropus in many aspects is less clear. NORMAN

(1934) noted to Etropus: “very close to Citharich-

thys, but eyes always separated by a narrow, bony

ridge”. Otoliths do show a certain tendency to

widen the sulcus. They are not always as com-

pressed as those of Orthopsetta and also even more

roundish in shape. Often, not only the postdorsal

but also the postventral rims are mildly concave.

However, all these otolith characters are so subtle

and so variable in nature that in my opinion oto-

liths of the two genera Orthopsetta and Etropus

will not always be distinguishable on the generic

level.

Species and distribution: Following the ichthyo-

logical parameters proposed for differentiation

of the two genera Citharichthys and Orthopsetta as

discussed in the entry to Citharichthys, I have ten-

tatively placed the following species in the genus

Orthopsetta: O, amblybregmatus, O. arctifrons,

O. cornutus, O. dinoceros and O. gymnorhinus from

the Atlantic coasts of America and O. fragilis,

O. mariajorsiae, O. sordidus, O. stigmaeus and

O. xanthostigma from the Pacific coasts of Amer-

ica. Except for O. dinoceros, O. gymnorhinus,

O. mariajorsiae and O. amblybregmatus otoliths are

known from all of these species.

Orthopsetta stigmaeus

(JORDAN & GILBERT 1883)

Figs. 276-278

Investigated otoliths: 5 otoliths (4 right side, figs.

277-278; 1 left side, fig. 276) from off California,

ZMH Ot. 14.5.1994.23-27 (leg. Fitch).

Variability: Variability within this species is rel-

atively small, restricted to details of the outline.

Discussion: O. stigmaeus in many aspects exhib-

its the most plesiomorphic otolith morphology

in this genus. The outline of the otoliths is round-

ed pentagonal, the sulcus still rather long with an

indistinct “fusiform” shape and the inner face is

slightly convex. Also it is more elongate than most

other species of the genus.

Distribution: Pacific coast of North America

from Oregon to southern California.

Orthopsetta sordidus (GIRARD 1856)

Figs. 279-282

syn. Metoponops cooperi GILL 1864

Investigated otoliths: 7 otoliths (4 right side, figs.

279, 280, 282; 3 left side, fig. 281) from off Califor-

nia, ZMH Ot. 14.5.1994.28-34 (leg. Fitch)

Ontogeny and variability: Otoliths of O. sordidus

show a rather strong degree of allometric ontoge-

netic changes. Otoliths of up to 3.5 mm in size are

Figs. 276-278: Orthopsetta stigmaeus (JORDAN & GILBERT 1883) – 15 ×

276

278c

278b

277

278a

149

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Figs. 279-282: Orthopsetta sordidus (GIRARD 1856) – 15 ×

Fig. 283: Orthopsetta fragilis (GILBERT 1891) – 15 ×

279

280c

280b

281

280a

282

283a

283c

283b

150

Schwarzhans: Pleuronectiformes

considerably less compressed than the large ones

of 4 to 4.5 mm length. Variations of the outline of

the otolith is moderate and mainly concerns the

expression of the dorsal and the posterior rims.

Discussion: O. sordidus differs from O. stigmae-

us in the more compressed and more rounded

outline and the rather wide and ovally shaped

sulcus. Even more closely related is O. fragilis,

which mainly differs in the more massive dorsal

field and the somewhat more thickset appear-

ance. However, once a larger series of otoliths of

O. fragilis becomes available, the limits between

the otoliths of both species may very well fade

away.

Distribution: Pacific coast of North America

from British Columbia to Lower California.

Orthopsetta fragilis (GILBERT 1891)

Fig. 283

Investigated otoliths: 1 otolith (right side) from

the Gulf of California, BMNH 1900.9.29.252.

Discussion: Very close to O. sordidus (see respec-

tive entry).

Distribution: Pacific coast of North America,

restricted to the Gulf of California.

Orthopsetta xanthostigma (GILBERT 1890)

Figs. 284-285

Investigated otoliths: 5 otoliths (3 right side,

fig. 284; 2 left side, fig. 285) from off California,

ZMH Ot. 14.5.1994.35-39 (leg. Fitch).

Variability: As in most species of this genus the

outline of the otolith is the character most strong-

ly affected by variability. However, in the case of

O. xanthostigma the degree of variations is rela-

tively small.

Discussion: Otoliths of O. xanthostigma are quite

compressed and exhibit a rather regularly round-

ed dorsal rim. The sulcus is wide, oval in shape

and rather short. The short sulcus and the shape

of the otolith distinguishes it from O. sordidus and

O. fragilis.

Distribution: Pacific coasts of North America,

both coasts of Lower California.

Orthopsetta arctifrons (GOODE 1881)

Figs. 286-289

Investigated otoliths: 5 otoliths (3 right side, figs.

287, 289; 2 left side, figs. 286, 288) from off Virgin-

ia, USA, ZMH Ot. 14.5.1994.40-44 (leg. ISH).

Variability: Details of the outline can be quite

variable in this species. This concerns presence

Figs. 284-285: Orthopsetta ×anthostigma (GILBERT 1890) – 15 ×

284a

285

284b

284c

151

Piscium Catalogus, Part Otolithi piscium, Vol. 2

or absence of a slight marginal crenulation as well

as degree of “roundness” of the outline. In gener-

al, however, otoliths are more regularly rounded

than those of any other species in the genus.

Discussion: Seemingly, O. arctifrons somewhat

stands apart from the rest of the species in this

genus. Their otoliths are easily recognized by their

almost round outline and the extremely short

sulcus.

Distribution: Atlantic coasts of North America,

in relatively deep waters (70 to 350 m) of the Gulf

Stream.

Orthopsetta cornutus (GÜNTHER 1880)

Figs. 290-291

syn. Citharichthys unicornis GOODE 1881

Investigated otoliths: 4 otoliths (2 right side,

fig. 290; 2 left side, fig. 291) West of Trinidad

(10°51’N/60°29’W), ZMH Ot. 14.5.1994.45-46 (leg.

ZMUC 853448-49) and ZMUC 853448-49.

Variability: Otoliths of this species seem to be

quite variable as far as their outline is concerned.

Discussion: O. cornutus probably shows the most

compressed and most thickset otoliths in this

genus. In fact, it is the only species in which the

ventral rim is more deeply curved than the dor-

sal rim. The sulcus is small and short. These char-

acters make O. cornutus quite unmistakable.

Distribution: Atlantic coast of Central America

and Brazil, in relatively deep waters (60 to 600 m)

of the Gulf Stream.

Etropus JORDAN & GILBERT 1882

Type-species: Etropus crossotus JORDAN & GIL-

BERT 1882

Diagnosis: Moderately thickset, small otoliths

with a compressed, rounded pentagonal shape;

ventral rim moderately curved, broadly rounded

or with a rounded medioventral angle, postven-

tral portion often concave, dorsal rim with rather

shallow predorsal projection and rounded post-

dorsal angle, predorsal projection not bend out-

ward, postdorsal portion straight or slightly con-

cave, posterior tip pointed or rounded, project-

ing, occupying a median position, anterior rim

blunt or rounded; index l:h 1.2 to 1.3. Otolith size

possibly not exceeding much 3.5 mm.

287a286

287b

287c

289

288

Figs. 286-289: Orthopsetta arctifrons (GOODE 1881) – 15 ×

152

Schwarzhans: Pleuronectiformes

Colliculi fused, distinction of ostium and cau-

da practically completely masked. Sulcus more

or less horizontal, oval in shape, not reduced in

length. Dorsal and ventral depressions moder-

ately deep, more or less continuously connected

around caudal tip to form a circumsulcal depres-

sion.

Inner face moderately convex to almost flat,

rather smooth; outer face flat to moderately con-

vex, usually smooth. Rims moderately sharp,

usually smooth, sometimes slightly undulated.

Measurements:

l:h h:t ol:cl (oh:ch) con.i

crossotus 1.25-1.30 4.5 nm nm 4.5

intermedius 1.20 4.0 nm nm 4.5

longimanus 1.10-1.25 3.4 nm nm 6.5

microstomus 1.15-1.20 3.5 nm nm 7.0

†concaviventris 1.05-1.15 3.3 nm nm 3.0

Side dimorphism: Not apparent.

Ontogeny and variability: Ontogenetic changes

do not seem to play a major role in the species of

this genus. Even small specimens of 1.5 to 2 mm

in size exhibit all pertinent diagnostic characters.

Variability on the other hand can be quite consid-

erable, as exemplified by the figures to

E. longimanus and concerns many aspects of the

outline of the otolith.

Discussion: As stated before otoliths of Etropus

are hardly distinguishable from those of the re-

lated genus Orthopsetta (see entry to this genus

for lengthy discussion). One useful character

adherent to many but not all species is the slight-

ly concave postventral rim. Likewise, NORMAN

(1934) stated that Etropus is very similar to Citha-

richthys (including Orthopsetta as a subgenus in

his views), but eyes are always separated by a

narrow, bony ridge.

Species and distribution: There are 9 nominal

recent species recorded, 7 from the Atlantic coasts

of America – E. crossotus, E. cyclosquamus, E. dels-

mani, E. intermedius, E. longimanus, E. microstomus

and E. rimosus – and 4 from the Pacific coast of

America – E. crossotus, E. delsmani, E. peruvianus

and E. ectenes. Thus E. crossotus and E. delsmani

are among of the very few species occurring si-

multaneously on both sides of America. Otoliths

are only known from 4 species, namely E. crosso-

tus, E. intermedius, E. longimanus and E. micro-

stomus. However, most of the remaining species

seem to be extremely rare, some of them based

on one or two specimens only. In addition, there

is a fossil record from the Upper Miocene of the

Dominican Republic, described here as E. con-

caviventris and possibly a second record from the

Miocene of Ecuador (com. pers. A. Müller).

Figs. 290-291: Orthopsetta cornutus (GÜNTHER 1880) – 15 ×

291

290a

290b

290c

153

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Etropus crossotus JORDAN & GILBERT 1882

Figs. 292-294

syn. Citharichthys crossotus atlanticus PARR 1931

Investigated otoliths: 3 otoliths (right side) from

off Mazatlan, Pacific coast of Mexico, ZMH Ot.

14.5.1994.47-48 (leg. BMNH 95.5.27.225-29) and

BMNH 95.5.27.225-29.

Variability: Variations in this species seems to

be limited to the expression of the predorsal pro-

jection.

Discussion: Otoliths of E. crossotus are very sim-

ilar to those of the various species of the genus

Citharichthys. Similar are the thin appearance, the

rather elongate and pentagonal outline of the

otolith and the long and narrow sulcus. Differ-

ences are so delicate that from otoliths alone one

would certainly be tempted to place this species

in the genus Citharichthys altogether.

Distribution: E. crossotus is the only Pleuronec-

tiform species occurring simultaneously on both

sides of America. In the Atlantic it is found from

Chesapeake Bay to the West Indies and in the

Pacific from Lower California to Panama.

Etropus intermedius NORMAN 1933

Fig. 295

Investigated otoliths: 1 otolith (right side) from

off Georgetown, British Guiana, BMNH 1950.5.

15.46.

Discussion: Very similar to both E. crossotus and

E. longimanus. Main difference is the strongly

developed predorsal projection resulting in a very

blunt anterior rim. Whether this character is suf-

ficient to distinguish otoliths of this species from

those of the two others mentioned before remains

to be verified once more material has become

available.

Distribution: Atlantic coast of South America

from Trinidad to Rio de Janeiro.

Figs. 292-294: Etropus crossotus JORDAN & GILBERT 1882 – 15 ×

Fig. 295: Etropus intermedius NORMAN 1933 – 15 ×

293

292a

294

295a

295b

292b

292c

154

Schwarzhans: Pleuronectiformes

Etropus longimanus NORMAN 1933

Figs. 296-299

Investigated otoliths: 5 otoliths (4 right side,

fig. 296-297, 299; 1 left side, fig. 298) from off Rio

de Janeiro, Brazil, ZMH Ot. 14.5.1994.49-52 (leg.

BMNH 1913.12.4.311-20) and BMNH 1913.12.4.

311-20.

Variability: As shown in the figures to this spe-

cies, variations of the outline of the otolith are

quite considerable, as are its proportions. In fact,

it is difficult to find a single character to define

the species by otoliths alone.

Discussion: E. longimanus is quite similar to

E. crossotus. Its otoliths are slightly more com-

pressed, more thickset and exhibit a much less

convex inner face. Also the sulcus is somewhat

shorter and wider.

Distribution: Southern Atlantic, coasts of Brazil

and Argentina.

Etropus microstomus GILL 1864

Figs. 300-301

syn. Citharichthys microps FOWLER 1911

Figs. 296-299: Etropus longimanus NORMAN 1933 – 15 ×

Figs. 300-301: Etropus microstomus GILL 1864 – 15 ×

297

296a

299

300a

300b

296b

296c

301

298

300c

155

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Investigated otoliths: 2 otoliths (right side) from

the Delaware Bay, Atlantic coast of North Amer-

ica, ZMH Ot. 14.5.1994.53 (leg. BMNH 1933.6.15.1)

and BMNH 1933.6.15.1.

Discussion: Otoliths of this species are easily

recognized by their roundish outline (except for

the concave postdorsal rim) and the rather wide

and deep sulcus.

Distribution: Atlantic coast of North America,

from New England to Florida.

Etropus concaviventris n.sp.

Figs. 302-304

Name: Combination of concavus (lat.) = concave,

and venter (lat.) = body, stomach; referring to the

strongly concave postventral rim of the otolith.

Holotype: Fig. 302, NMB 15896a.

Type locality: Rio Gurabo river banks, Cibao

Valley, northern Dominican Republic.

Age: Cerrado Formation, Upper Miocene.

Paratypes: 2 otoliths (figs. 303-304), topo- and

stratitypic, NMB 15896b and NMB 16922.

Diagnosis: Compressed otoliths with rounded

pentagonal outline. Postdorsal portion higher

than predorsal portion. Postventral rim distinct-

ly concave. Inner face markedly convex.

Description: Small, compressed, moderately

thick otoliths with a rounded pentagonal outline.

Dorsal rim rather rounded, highest posteriorly,

ventral rim deeply bodied with distinct and long

concave postventral portion, posterior tip short,

pointed, situated slightly inframedianly, anterior

tip blunt.

Inner face: Rather strongly convex and

smooth. Sulcus moderately long, horizontal, with

completely fused colliculi, indistinctly “fusiform”

in shape. Sulcus opening reduced, medial. Dor-

sal and ventral depressions rather shallow, mod-

erately wide and connected around the caudal

tip.

Other views: Rims moderately sharp and

smooth, postdorsal rim sometimes slightly crenu-

lated. Outer face more or less smooth, flat.

Side dimorphism: Not apparent.

Ontogeny and variability: The smallest speci-

men is 1.5 mm long but does not differ signifi-

cantly from the largest specimen of about 2.3 mm

length. All specimens exhibit suitable diagnostic

characters indicating that morphological maturi-

ty in this species is reached at relatively small

otolith sizes. Variability is moderate, restricted to

details in the expression of the dorsal rim, projec-

tion of the posterior tip and details in the outline

of the sulcus.

Discussion: E. concaviventris is readily recog-

nized by the pronounced concavity of the

postventral rim in combination with the shape of

the dorsal rim and the rather convex inner face.

It resembles species of the genus Etropus as well

as Citharichthys. I have tentatively placed it in the

former because of the strongly concave postven-

tral rim and the somewhat reduced outline of the

sulcus.

Figs. 302-304: Etropus concaviventris n.sp. – 15 ×

302c

303

304

302a

302b

156

Schwarzhans: Pleuronectiformes

Bothinae

7.6.5 Bothus Group

Genera: Three genera – Bothus, Parabothus and

Grammatobothus. This group is particularly well

represented in the Indo-Pacific, but one of its

genera – Bothus – is also found in the Mediterra-

nean and the Atlantic. In addition, there is a sin-

gle otolith based fossil record of the genus Gram-

matobothus from the Miocene of Europe (Poland,

Paratethys).

Definition and relationship: Together with the

Arnoglossus, Monolene-Laeops and Engyprosopon

Groups described later the Bothus Group consti-

tutes the bulk of the genera placed into the sub-

family Bothinae by NORMAN (1934), respectively

Bothidae by HENSLEY & AHLSTROM (1984).

The otoliths of the four groups in general are

rather small, oval to roundish to rectangular in

shape and with an ostial to pseudoostial sulcus

opening. Dorsal and ventral depressions are usu-

ally well marked and deep and often well con-

nected around the caudal tip. The ostium is al-

most always considerably longer than the cauda

and slightly wider too. This combination of char-

acters puts these groups well apart from the four

other bothid otolith groups described before and

in a way supports NORMAN’s concept to subdi-

vide the Bothidae into two subfamilies. Howev-

er, the line of subdivision according to otolith

grouping slightly departs from NORMAN’s con-

cept (not so much from HENSLEY & AHL-

STROM’s concept), and this is being dealt with

in the respective chapter to the Monolene-Laeops

Group.

The otoliths of the Bothus Group are quite thin,

with a distinctly convex inner face and a round-

ed oval outline. In most instances, the sulcus open-

ing is clearly ostial. It is this combination that

distinguishes otoliths of the Bothus Group from

the more compressed and massive otoliths of the

other groups. However, the line of distinction is

somewhat fluent and there are some genera, such

as Parabothus, Crossorhombus or Engyprosopon,

which could be placed in the one or the other

group. In conclusion, the otoliths of both the

Bothus Group as well as of the other three groups

are characterized by a number of morphological

reductions, which sometimes result in analytical

uncertainties at all taxonomic levels. This is par-

ticularly true for the Arnoglossus and the Mono-

lene-Laeops Group and is being discussed there in

more detail.

Bothus RAFINESQUE 1810

Type-species: Bothus rumulo RAFINESQUE 1810

(syn. B. podas)

syn. Platophrys SWAINSON 1839 (type-species:

Rhombus ocellatus)

syn. Peloria COCCO 1844 (type-species: Peloria

heckeli, syn. B. podas)

syn. Coccolus BONAPARTE 1846 (type-species:

Coccolus annectens, syn. B. podas)

syn. Rhomboidichthys BLEEKER 1856 (type-spe-

cies: Rhomboidichthys myriaster) subgenus

syn. Psettylis ALCOCK 1890 (type-species: Pset-

tylis pelucida – acc. to NORMAN 1934, post-

larval spec. indet.)

syn. Pseudocitharichthys WEBER 1913 (type-spe-

cies: Citharichthys aureus, syn. B. pantherinus)

syn. Platotichthys NICHOLS 1921 (type-species:

Platotichthys chartes – acc. to NORMAN 1934,

post-larval of B. lunatus)

syn. Symboulichthys CHABANAUD 1927 (type-

species: Platophrys maculifer)

Diagnosis: Relatively thin, small to very small

otoliths with a rounded oval shape; ventral and

dorsal rims gently curved, without major angles,

posterior tip variable, rounded, blunt or project-

ing, anterior rim rounded or with short rostrum,

then usually with faint excisura; index l:h 1.2 to

1.7. Otolith size rarely exceeding 3 mm, in fact

otoliths are rather small in comparison to size of

fish.

Ostium slightly longer than cauda and slight-

ly wider too. Sulcus narrow, deep, often with clear

ostial opening. Excisura sometimes developed.

Cauda terminating not very far from posterior

tip of otolith. Colliculi separated, but distinction

of ostium and cauda often very indistinct. Dorsal

and ventral depressions narrow, but rather deep

and well marked, indistinctly connected around

caudal tip to form a circumsulcal depression.

Inner face convex, not very smooth; outer face

flat to slightly concave, with little ornamentation.

Rims sharp, usually smooth, sometimes slightly

undulating.

157

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Measurements:

l:h h:t ol:cl oh:ch con.i

subgenus Bothus

podas 1.40 2.3 1.3 1.4 3

pantherinus 1.55-1.65 3.0 1.3-1.8 1.2-1.5 3

ocellatus 1.60-1.70 2.7 1.5-1.6 1.2 4

constellatus 1.50-1.55 3.0 1.3-1.5 1.2-1.3 2.8

lunatus 1.60 3.0 1.2 1.2 2.5

subgenus Rhomboidichthys

myriaster 1.25 2.7 1.7-1.9 1.2-1.3 3

mancus 1.30 nm 1.1 1.2-1.3 nm

Side dimorphism: Side dimorphism in this ge-

nus is quite inconspicuous and may vary from

species to species. A series of specimens from

B. podas figured by CHAINE (1936) indicate that

right hand otoliths tend to be more regularly

rounded in outline and left hand otoliths show a

stronger tendency towards development of an

excisura. This observation is also confirmed by

otoliths of B. pantherinus, but in B. myriaster it is

the other way round, and otoliths of B. ocellatus

show virtually no side dimorphism. NOLF (1985)

stated that some species of Bothus do not show

any side dimorphism (example used was B. po-

das) and others a very strong side dimorphism

(example was B. lunatus). His interpretation was

based on a very compressed right hand otolith of

B. lunatus (NOLF, 1985 – fig. 15 C2). A right hand

specimen of the same species available to me does

not show this habitus, but rather fits with the left

hand specimen he figured. Judging from this, the

compressed right side otolith of B. lunatus as fig-

ured by NOLF rather represents a singular case

of teratological deformation than a valid case of

side dimorphism.

Sexual dimorphism: The fishes of the genus Both-

us like several other Bothinae genera (Engypro-

sopon, Crossorhombus, Perissias, Parabothus and one

species of Syacium) are well known for a sexual

difference in the width of the interorbital region.

The interorbital region in those genera is wider in

males than it is in females and this curious fea-

ture attains its maximum development in certain

species of the genus Bothus (= Platophrys auctt.).

It may be expected that this development is also

reflected in some kind of sexual dimorphism in

otoliths. And indeed this seems to be the case

with the genus Syacium (S. ovale – see respective

entry). In the case of Bothus and the other genera

mentioned presently available otolith material,

unfortunately, is not sufficient for such an inves-

tigation.

Ontogeny and variability: So far too few oto-

liths are known from this genus to allow for any

analysis of ontogenetic changes. However, since

otoliths in general are very small it seems that

diagnostic maturity is reached already with rela-

tively small specimens in the order of 1.5 to 2 mm.

Judging from CHAINE’s (1936) figures of B. podas

intraspecific variability is moderate and only

concerns details of the outline of the otolith and

expression of the excisura, both characters which

are also touched by the effects of side dimorphism.

Discussion: Bothus otoliths resemble both Pa-

rabothus and Grammatobothus otoliths. In the two

latter genera the inner faces of the otoliths are

less convex and the postventral angle is always

quite well developed. In Parabothus the ostial

opening is somewhat reduced, but this is also the

case in certain Bothus species (see for instance

B. ocellatus).

The genus Bothus contains some 18 nominal-

ly valid species. Otoliths are known from 8 of

them. From this it appears that at least two differ-

ent morphologies can be recognized from oto-

liths. One group comprises relatively elongate,

oval otoliths, mostly without excisura (except for

B. lunatus), whereas the other group comprises

roundish, compressed otoliths, which are ex-

tremely small in comparison to the size of the

fishes from which they have been taken. Availa-

ble generic names are attributed to the two groups

in subgeneric ranking – the first would become

the subgenus Bothus, the second the subgenus

Rhomboidichthys. Realizing, however, that otoliths

are only known from about half of the recent

species of this genus one may expect more poten-

tial for such subdivisions.

Species and distribution: 18 nominally valid

species: B. podas, B. mellissi and B. guibei from the

Mediterranean and East Atlantic, B. ocellatus,

B. lunatus, B. maculiferus, B. robinsi and B. ellipticus

from the West Atlantic,

B. leopardinus and B. con-

stellatus from the Pacific coast of America and

B. mancus, B. pantherinus, B. bleekeri, B. myriaster,

B. ovalis, B. tricirrhatus, B. ypsigrammus and B. as-

similis from the Indo-West-Pacific. Thus the ge-

nus Bothus is one of the most widely distributed

genera of Pleuronectiformes. NORMAN (1934)

has explained this unusually wide distribution

pattern of the genus by a prolonged early pelagic

life adherent to the larval stage.

158

Schwarzhans: Pleuronectiformes

Bothus (Bothus) podas (DELAROCHE 1809)

Fig. 305

syn. Pleuronectes argus RISSO 1810

syn. Bothus rumulo RAFINESQUE 1810

syn. Solea rhomboides RAFINESQUE 1810

syn. Bothus diaphanus RAFINESQUE 1814

?syn. Rhombus candidissimus RISSO 1820

syn. Rhombus gesneri RISSO 1826

syn. Rhombus heterophthalmus BENNETT 1831

syn. Rhombus rhomboides BONAPARTE 1833

syn. Rhombus maderensis LOWE 1834

syn. Rhombus serratus VALENCIENNES 1843

syn. Peloria heckelii COCCO 1844

?syn. Coccolus annectens BONAPARTE 1846

Investigated otoliths: 1 otolith (right side) from

off Calabria, Italy, ZMH Ot. 16.5.1994.1 (leg. ZMH

19932).

Discussion: Otoliths of B. podas are more com-

pressed and more regularly rounded than those

of the other species investigated.

Distribution: Mediterranean and East Atlantic,

from Portugal to Angola and westward to Ma-

deira and the Canaries.

Bothus (Bothus) pantherinus (RÜPPEL 1830)

Figs. 306-307

syn. Rhombus parvimanus BENNETT 1832

syn. Rhombus sumatranus BLEEKER 1851

?syn. Passer marchionessarum VALENCIENNES

1855

syn. Pleuronectes lunulatus JOUAN 1861

?syn. Citharichthys aureus DAY 1877

Investigated otoliths: 2 otoliths (right and left

side) from off Zanzibar, ZMH Ot. 16.5.1994.2-3

(leg. ZMH 19925).

Discussion: Otoliths of B. pantherinus are quite

similar to those of B. podas, but are more elongate

and thin.

Distribution: Indian Ocean from East Africa and

the Red Sea to Indonesia, Australia and the Pacific.

Bothus (Bothus) ocellatus (AGASSIZ 1831)

Figs. 308-309

syn. Rhombus bahianus CASTELNAU 1855

syn. Platophrys nebularis JORDAN & GILBERT

1885

?syn. Bothus atlanticus KYLE 1913

Investigated otoliths: 2 otoliths (right and left

side) from off Georgia, USA, ZMH Ot. 16.5.1994.4-

5 (leg. Fitch).

Discussion: B. ocellatus is easily recognized by

its anteriorly pronounced dorsal rim and the

somewhat reduced ostial opening.

Distribution: Atlantic coast of America, from

New York to Rio de Janeiro.

Bothus (Bothus) constellatus

(JORDAN & GOSS 1889)

Figs. 310-313

Investigated otoliths: 4 otoliths (3 right and one

left) from the Galapagos Isl., ZMH Ot. 2.1.1995.13-

15 (leg. BMNH 1938.12.12.163-5) and BMNH

1938.12.12.163-5.

Fig. 305: Bothus (Bothus) podas (DELAROCHE 1809) – 15 ×

Figs. 306-307: Bothus (Bothus) pantherinus (RÜPPEL 1830) – 15 ×

305c

305b

305a

306a

306c

306b

159

Piscium Catalogus, Part Otolithi piscium, Vol. 2

NORMAN (1934) doubted B. constellatus to

be distinct from B. leopardinus (GÜNTHER 1862)

from the Pacific coast of tropical America. Of the

latter species otoliths so far are missing for com-

parison.

Distribution: Panama Bay (Pacific) and Galapa-

gos Islands.

Bothus (Bothus) lunatus (LINNAEUS 1758)

Fig. 314

syn. Pleuronectes argus BLOCH 1783

?syn. Pleuronectes surinamensis SCHNEIDER 1801

syn. Platotichthys chartes NICHOLS 1921

Investigated otoliths: 1 otolith (right side) from

off St. Thomas, Caribbean, ZMH Ot. 16.5.1994.6

(leg. ZMH 19894).

Discussion: Quite similar to B. podas but more

elongate. Otoliths of B. pantherinus are more thin

and less regularly rounded in outline. Those of

B. ocellatus from the Atlantic coast of North Amer-

ica are somewhat narrowed posteriorly.

312c

310

309a

312a

309c

309b

308

312b

311

313

Figs. 308-309: Bothus (Bothus) ocellatus (AGASSIZ 1831) – 15 ×

Figs. 310-313: Bothus (Bothus) constellatus (JORDAN & GOSS 1889) – 15 ×

Fig. 314: Bothus (Bothus) lunatus (LINNAEUS 1758)

– 15 ×

160

Schwarzhans: Pleuronectiformes

Discussion: The otolith of B. lunatus is very thin

and fragile, with a rather strongly convex inner

face, a deep excisura and a rather pronounced

postdorsal angle.

Distribution: Atlantic coast of America, from

Florida to northern Brazil and eastward to Fern-

ando Noronha Isl.

Bothus (Rhomboidichthys) myriaster

(TEMMINCK & SCHLEGEL 1846)

Figs. 315-316

syn. Platophrys circularis FRANZ 1910

Investigated otoliths: 2 otoliths (left and right)

from off Formosa, ZMH Ot. 2.1.1994.17 (leg.

BMNH 1933.6.12.4) and BMNH 1933.6.12.4.

Discussion: A small, easily recognized thin oto-

lith with almost circular outline, convex inner face

and concave outer face. All rims are intensely

crenulated.

Distribution: Coasts of China, Japan, Formosa

and Indo-China.

Bothus (Rhomboidichthys) ovalis

(REGAN 1908)

Remarks: The only otolith extracted from a fish

caught off India (BMNH 1928.3.20.135) was too

much eroded by formalin to warrant a figure.

Nevertheless, it was apparent that the otolith must

have been quite similar to those of B. myriaster,

may be slightly more elongate. NORMAN (1934)

regarded both species as closely related, proba-

bly synonymous.

Distribution: Coasts of India to Burma and

Amirantes Islands.

Bothus (Rhomboidichthys) mancus

(BROUSSONET 1782)

Fig. 317

syn. Pleuronectes spinosus SCHNEIDER 1801

syn. Rhombus macropterus QUOY & GAIMARD

1824

syn. Pleuronectes pictus FORSTER 1844

syn. Rhombus pavo BLEEKER 1855

syn. Platophrys smithi RENDAHL 1921

Investigated otoliths: 1 otolith (right side) from

the Tarawa lagoon, Gilbert & Ellice Islands, Poly-

nesia, BMNH 1969.8.26.239-302.

Discussion: The only otolith available is some-

what eroded, in particular the sulcal portion of

the inner face. It is characterized by its extremely

small size compared to the size of the fish.

B. mancus differs from B. myriaster in the rather

flat ventral rim and the lack of marginal crenula-

tion.

Distribution: Widely distributed in the Indo-

West-Pacific from China to the Micronesian and

Polynesian Islands to the Maldives.

Figs. 315-316: Bothus (Rhomboidichthys) myriaster (TEMMINCK & SCHLEGEL 1846) – 15 ×

Fig. 317: Bothus (Rhomboidichthys) mancus (BROUSSONET 1782) – 15 ×

315

316b

316a

317

316c

161

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Parabothus NORMAN 1931

Type-species: Arnoglossus polylepis ALCOCK 1889

Diagnosis: Moderately thin, small otoliths with

an irregular oval shape; ventral rim gently curv-

ing, dorsal rim with rounded predorsal and pro-

nounced postdorsal angles, straight and horizon-

tal in between, posterior tip blunt or faintly point-

ed, anterior rim rounded or blunt, without

marked rostrum, nor excisura; index l:h about

1.5. Otolith size probably not exceeding 3 mm.

Ostium longer than cauda and slightly wider

too. Sulcus moderately narrow, deep, with slightly

reduced opening. Cauda terminating not very far

from posterior tip of otolith. Colliculi separated,

distinction usually well marked. Dorsal and ven-

tral depressions rather deep and well marked,

indistinctly connected around caudal tip to form

a circumsulcal depression.

Inner face slightly convex, not very smooth;

outer face flat, with little ornamentation. Rims

moderately sharp, smooth.

Measurements:

l:h h:t ol:cl oh:ch con.i

chlorospilus 1.45-1.50 2.5 1.3-1.6 1.1-1.3 3.5

Side dimorphism: Like in the related genus Both-

us side dimorphism is very indistinct. It so seems

that the reduction of the sulcus opening is stronger

in right hand than in left hand otoliths.

Variability: Some of the proportions can be quite

variable, particularly as far as the sulcus is con-

cerned. Also the posterior tip of the otolith can be

pointed or blunt and nearly vertically cut.

Discussion: Close to Bothus (see respective en-

try) and Grammatobothus. The latter differs in

being more elongate and always showing a clear

sulcus opening.

Species and distribution: NORMAN (1934) and

MASUDA et al. (1984) reported 4 species – P. po-

lylepis, P. chlorospilus, P. coarctus, P. kiensis – plus 4

somewhat problematical additional species which

were based on unique holotypes – P. amaokai, P. tai-

wanensis, P. violaceus, P. malhensis. All species are

from the Indo-Pacific. Otoliths are only known

from a single species, P. chlorospilus.

Parabothus chlorospilus (GILBERT 1905)

Figs. 318-320

syn. Platophrys inermis GILBERT 1905

Investigated otoliths: 3 otoliths (two right side

and one left side) from off Hawaii, ZMH Ot.

16.5.1994.7-9 (leg. Fitch).

Discussion: See entry to genus.

Distribution: Hawaiian Islands.

Grammatobothus NORMAN 1926

Type-species: Platophrys polyophthalmus BLEEK-

ER 1866

Diagnosis: Moderately thin, small to medium

sized otoliths with an elongated rectangular

shape; ventral rim shallow, gently curving, dor-

sal rim straight, horizontal, with marked pre- and

postdorsal angles, posterior tip blunt, anterior rim

blunt, with faint excisura and short rostrum; in-

dex l:h about 1.7. Otolith size up to 4 mm and

possibly more.

Figs. 318-320: Parabothus chlorospilus (GILBERT 1905) – 15 ×

318

319b

319a

320

319c

162

Schwarzhans: Pleuronectiformes

Ostium slightly longer than cauda and slight-

ly wider too. Sulcus moderately narrow, deep,

with clear ostial opening. Cauda terminating not

very far from posterior tip of otolith. Colliculi

separated, but distinction of ostium and cauda

often very indistinct. Dorsal and ventral depres-

sions narrow, but rather deep and well marked,

more or less connected around caudal tip to form

a circumsulcal depression.

Inner face slightly convex, not very smooth;

outer face flat, with little ornamentation. Rims

moderately sharp, usually smooth, sometimes

slightly undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

polyophthalmus 1.70 2.8 1.5-1.8 1.2-1.3 5

†radwanskae 1.70-1.75 2.8 0.8-1.0 1.1-1.2 4

†awamoaensis 1.80 2.9 1.45 1.1 4

Side dimorphism: Not apparent.

Variability: Variations concern details of the ex-

pression of the dorsal rim, development of the

rostrum and proportions of the sulcus.

Discussion: Close to Bothus and Parabothus (see

respective entries).

Species and distribution: Grammatobothus is

known from 3 recent species from the Indo-Pacif-

ic – G. polyophthalmus, G. pennatus, G. krempfi – and

two fossil species, one from the Middle Miocene

of Poland (Paratethys) – G. radwanskae – the other

from the Lower Miocene of New Zealand –

G. awamoaensis.

Grammatobothus polyophthalmus

(BLEEKER 1866)

Figs. 321-322

syn. Rhomboidichthys angustifrons GÜNTHER

1880

Investigated otoliths: 2 otoliths (right and left

side) from Pukhet, Thailand, ZMH Ot. 16.5.

1994.10-11 (leg. ZMUC P 853412).

Discussion: The otoliths of G. polyophthalmus are

somewhat smaller than those of the fossil

G. radwanskae, but otherwise are quite similar ex-

cept for the sulcus proportions.

Distribution: From the Indian Ocean through the

Malay Peninsula and Indonesia to Australia.

Grammatobothus radwanskae n.sp.

Figs. 323-325

syn. genus Bothidarum sp. – RADWANSKA 1992:

fig. 159, pl. 36, fig. 11-12

Name: In honor to Mrs. U. Radwanska (Warsaw)

and her outstanding monograph on otoliths from

the Polish Miocene.

Holotype: Fig. , ZPalUW/Rak-441.

Type locality: Korytnica, southern Holy Cross

Mountains, southern Poland.

Age: Korytnica Clay, Badenian, Middle Miocene.

Paratypes: 2 otoliths, topo-and stratitypic,

ZPalUW/Rak-442.

Diagnosis: Elongate, moderately thickset otoliths

with roughly rectangular outline. Excisura and

short rostrum present. Sulcus deep, long, with

Figs. 321-322: Grammatobothus polyophthalmus (BLEEKER 1866) – 15 ×

321

322b

322a

322c

163

Piscium Catalogus, Part Otolithi piscium, Vol. 2

clear ostial opening. Dorsal and ventral depres-

sion distinct, deep.

Description: Outline: Rather elongate, moderate-

ly large and massive otoliths with roughly rec-

tangular outline. Dorsal rim straight, horizontal,

somewhat undulating, with rounded predorsal

and prominent postdorsal angles. Ventral rim

shallow, gently curving. Posterior tip blunt, near-

ly vertically cut. Anterior rim blunt, with excisu-

ra and short rostrum.

Inner face: Moderately convex and not very

smooth. Sulcus long, median, deep, clearly open-

ing anteriorly, posteriorly terminating not very

far from posterior tip of otolith. Partition into

ostium and cauda indistinct, but ostium usually

not longer than cauda, sometimes considerably

shorter. Dorsal and ventral depressions narrow,

deep, well marked, more or less connected around

caudal tip.

Other views: Rims moderately sharp and

mostly smooth. Outer face smooth, flat to very

slightly concave.

Side dimorphism: Not apparent, but index ol:cl

may be smaller in right hand otoliths than in left

hand otoliths.

Variability: Ornamentation of the otolith rims

and proportions of the sulcus seem to be some-

what variable.

Discussion: Otoliths of G. radwanskae are quite

similar to those of the recent G. polyophthalmus.

The most obvious character to distinguish the two

species is the proportion of ostium to cauda

length. In G. polyophthalmus the ostium is much

longer than the cauda, whereas in G. radwanskae

it is either shorter or of about the same length.

Grammatobothus awamoaensis n.sp.

Figs. 326

Name: Named after the type location – Awamoa

Creek – in New Zealand.

Holotype: Fig. 326, NZGS.

Type locality: Awamoa Creek, Otago, New Zea-

land South Island.

Age: Altonian, Lower Miocene.

324

323b

323a

323c

325

Figs. 323-325: Grammatobothus radwanskae n.sp. – 15 ×

164

Schwarzhans: Pleuronectiformes

Diagnosis: Elongate, rather thin otolith with

rounded rectangular outline. No excisura, short

rostrum present. Sulcus moderately deep, long,

with slightly reduced ostial opening. Dorsal and

ventral depression distinct, deep.

Description: Outline: Rather elongate, moderate-

ly large and rather thin otolith with rounded rec-

tangular outline. Dorsal rim straight, horizontal,

with rounded predorsal and prominent postdor-

sal angles. Ventral rim more deeply, gently curv-

ing. Posterior tip rounded. Anterior rim ventral-

ly pointed, with short rostrum.

Inner face: Moderately convex and not very

smooth. Sulcus long, slightly supramedian, mod-

erately deep, anterior opening somewhat reduced.

Partition into ostium and cauda distinct, ostium

somewhat longer than cauda. Dorsal and ventral

depressions narrow, deep, well marked, more or

less connected around caudal tip.

Other views: Rims sharp and smooth. Outer

face smooth, flat to very slightly concave.

Discussion: The otolith of G. awamoaensis is more

elongate than those of the two other species and

also characterized by its somewhat reduced sul-

cus opening and the thin appearance.

7.6.6 Arnoglossus Group

Genera: In this group I have tentatively placed 6

genera – Neolaeops, Arnoglossus, Caulopsetta, Lo-

phonectes, Psettina and Taeniopsetta. Most of these

genera are concentrated in the Indo-Pacific, but

the very large genus Arnoglossus is also well

known from the East Atlantic and the Mediterra-

nean. It is not reported from the shores of the

Americas. Otoliths are known from all genera.

Fossil records of Arnoglossus are common in Eu-

rope, NW-Africa and New Zealand and date well

back into Eocene times. Caulopsetta and Taeni-

opsetta are also known from the Miocene of New

Zealand.

Definition and relationship: Otoliths of the Ar-

noglossus Group are rather compact and small,

compressed to moderately elongate and rectan-

gular to rounded rectangular in outline. The sul-

cus typically is deep and somewhat inclined. Its

opening is slightly reduced in most instances.

Dorsal and ventral depressions are deep and more

or less well connected around the caudal tip. The

inner face in most instances is rather flat, but there

are few cases where it is markedly convex.

The somewhat inclined sulcus in combina-

tion with the usually relatively flat inner face and

the more or less rectangular outline are the main

characters that distinguish otoliths of the Arnoglos-

sus Group from the supposed related groups. The

other extreme is found in the Bothus Group with

its more gently curving outline, the horizontal

sulcus (often with a clear ostial opening) and the

markedly convex inner face. Otoliths of the Mo-

nolene-Laeops Group are similar to those of the

Arnoglossus Group in their compact and com-

pressed appearance, including the flat inner face.

Differing, however, these otoliths do not show

much of an inclined sulcus and also the outline is

more trapezoidal than rectangular. Otoliths of the

Engyprosopon Group finally exhibit a combina-

tion of characters of the Arnoglossus and the Both-

us Groups. With the latter they share the strongly

convex, often rather smooth inner face, with the

Arnoglossus Group the compact appearance and

the (rounded) rectangular outline. Also the sul-

cus sometimes is slightly inclined. However, as

already stated in the introductory note to the

Bothus Group, otoliths of all four groups are char-

acterized by certain trends in reduction of the

morphology. Therefore, definition and delimita-

tion of these groups is somewhat fluent and much

less certain than for the other bothid otolith

groups. As it stands now, the differentiation of

the Bothus, Arnoglossus, Monolene-Laeops and the

Engyprosopon Groups must be viewed as a very

tentative one. It should be noted, however, that

NORMAN in his analysis of the bothids also as-

sumed the genera here included in the Arnoglos-

sus Group to be closely related, but except for

Taeniopsetta.

Fig. 326: Grammatobothus awamoaensis n.sp. – 15 ×

165

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Neolaeops AMAOKA 1969

Type-species: Laeops microphthalmus VON BON-

DE 1922

Diagnosis: Relatively thick, small otoliths with

a rounded rectangular outline; ventral rim shal-

low, gently curved, dorsal rim flat, horizontal,

with rounded pre-and postdorsal angles, poste-

rior tip blunt, nearly vertically cut, anterior rim

blunt, with incipient short rostrum, but without

excisura; index l:h about 1.4. Otolith size about

3 mm.

Ostium longer than cauda and slightly wider

too. Sulcus narrow, moderately deep, very slight-

ly inclined, with a slightly reduced ostial open-

ing. Cauda terminating at some distance from

posterior tip of otolith. Colliculi well separated.

Dorsal and ventral depressions moderately deep

and well marked, connected around caudal tip to

form a circumsulcal depression.

Inner face almost flat in horizontal direction

and only slightly convex in vertical direction,

rather smooth; outer face convex, smooth. Rims

moderately sharp, slightly and irregularly undu-

lating.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

microphthalmus 1.45 2.7 1.3 1.3 5° 6

Side dimorphism: Not known.

Discussion: Within the Arnoglossus Group the

otolith of Neolaeops probably represents the most

plesiomorphic morphology. This is indicated by

the rounded rectangular outline, the very feeble

inclination of the sulcus and the presence of a

very small rostrum. In fact, Neolaeops could also

be regarded as a plesiomorphic representative of

the Monolene-Laeops Group. Morphologically, it

bridges between the two groups.

Species and distribution: Neolaeops contains but

a single recent species – N. microphthalmus – which

is widely distributed throughout the Indo-West-

Pacific, from South Africa to Japan. NORMAN

(1934) tentatively included N. microphthalmus

within the genus Arnoglossus as well as A. inter-

medius, which is now placed in the monospecific

genus Asterorhombus.

Neolaeops microphthalmus

(VON BONDE 1922)

Fig. 327

Investigated otoliths: 1 otolith (right side) from

off Kochi, Japan, ZMH Ot. 16.5.1994.12 (leg. Sas-

aki).

Discussion and distribution: See entry to

genus (monospecific genus).

Arnoglossus BLEEKER 1862

Type-species: Pleuronectes arnoglossus SCHNEI-

DER 1801 (syn. A. laterna)

syn. Bascanius SCHIODTE 1868 (type-species:

Bascanius taedifer, syn. A. rueppellii)

syn. Anticitharus GÜNTHER 1880 (type-species:

Anticitharus polyspilus)

syn. Charybdia FACCIOLA 1885 (type-species:

Peloria rueppellii)

syn. Scidorhombus TANAKA 1915 (type-species:

Scidorhombus pallidus)

syn. Kyleia CHABANAUD 1931 (type-species:

Arnoglossus thori)

syn. Dollfusiana CHABANAUD 1933 (type-spe-

cies: Peloria rueppellii)

syn. Dollfusetta WHITLEY 1950 (substitute for

Dollfusiana)

Diagnosis: Mostly thickset, small and compact

otoliths with a rectangular or rounded rectangu-

lar outline; ventral rim shallow, gently curved to

almost straight and horizontal, dorsal rim flat,

horizontal, with rounded pre-and postdorsal

angles, postdorsal angle usually more strongly

Fig. 327: Neolaeops microphthalmus

(VON BONDE 1922) – 15 ×

166

Schwarzhans: Pleuronectiformes

pronounced, posterior tip blunt, nearly vertically

cut, anterior rim blunt, without rostrum; index

l:h 1.1 to 1.7. Otolith size up to 3.5 – 4 mm.

Ostium longer than cauda and slightly wider

too. Sulcus narrow, deep to very deep, inclined,

usually with a slightly reduced ostial opening.

Cauda terminating at moderate distance from

posterior tip of otolith. Colliculi well separated,

deepened. Dorsal and ventral depressions deep

to very deep, well marked, connected around

caudal tip to form a circumsulcal depression.

Inner face almost flat to slightly convex in

horizontal direction and only slightly convex in

vertical direction, not smooth; outer face flat to

convex, mostly smooth. Rims moderately sharp

or thickened, smooth to slightly and irregularly

undulating.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

laterna 1.20-1.40 2.8 1.8-2.2 1.2-1.3 10° 5.5

macrostoma 1.50-1.60 2.0-2.6 1.5-1.8 1.0-1.3 5° 5.5

thori 1.45-1.65 2.5 1.5-1.7 1.1-1.3 5-10° 4

grohmanni 1.70-1.85 2.5 1.1-1.5 1.2-1.3 5° nm

imperialis 1.55-1.75 2.3 1.4-1.5 1.0-1.1 5° 4

†holleri 1.15-1.30 2.6-2.8 1.4-1.7 1.2-1.4 10° 3

†taureri 1.10-1.30 2.5-2.6 1.5-2.0 1.2-1.4 10-15° 5

†kokeni 1.10-1.20 2.4-2.7 1.8-2.2 1.2-1.3 10-15° -5

†quadratus 1.25-1.30 2.0-2.3 1.3-1.7 1.3-1.5 5-10° 5-6

capensis 1.65 2.0 1.6 1.1 5° 2.5

rueppellii 1.45 nd 2.2 1.2 20° nd

tapeinosoma 1.25-1.35 2.5 1.8-2.0 1.1 20° 3.5

waitei 1.35 2.7 1.7 1.5 10° 3.5

aspilos 1.20 2.7 1.6 1.3 15° 4.5

†lapierrei 1.35 2.0 1.5 1.1 25° 2.8

†prudhommae 1.10 3.2 1.8 1.2 25° 4

†extremus 1.50 nd 1.0 1.0 25° nd

†novus 1.15-1.20 2.2 1.6-2.0 1.1-1.2 25° 2.8

†longus 1.35-1.55 2.2 1.4-1.9 1.1 10° 3.5

†grenfelli 1.35-1.45 2.5-2.6 1.4-1.5 1.1-1.2 10° 4-5

debilis 1.30 3.4 1.4 1.2 10° 6

dalgleishi 1.30-1.40 3.2 1.5-1.8 1.1 10° 5.5

Side dimorphism: Not apparent.

Ontogeny and variability: Ontogenetic changes

in the otoliths of this genus are quite considera-

ble and so is intraspecific variability. Due to the

somewhat “reduced” morphological habitus of

the otoliths relatively few features are left for

diagnosis and differentiation of species. Many of

them concern outline and proportions of the oto-

liths, and these are the very characters most

strongly affected by intraspecific variations. In

several instances relatively large series of speci-

mens will be needed to reliably distinguish be-

tween otoliths of related species (see for instance

entries to A. laterna or A. imperialis).

Likewise, ontogenetic effects need to be dealt

with in great care. Small otoliths of less than

1.5 mm (sometimes 2 mm) of length are often so

much generalized in appearance that related spe-

cies can not be distinguished (see entries to A. lon-

gus and A. novus). Again it is mostly the outline

that is affected. There are also few cases, where

juvenile otoliths look quite different from adults

due to additional changes in the marginal orna-

mentation (see entry to A. quadratus). Unfortu-

nately, ontogenetic (and erosive) effects have not

always been taken into consideration in the de-

scriptions of the many fossil species. This has led

to a rather chaotic taxonomic situation in fossils,

particularly as far as secondary references are

concerned. I was not able to check all the various

secondary references in literature and therefore

have restricted myself to reviewing mainly pri-

mary references plus a certain selection of sec-

ondary references when available and important

for faunal reconstructions. The aim was to estab-

lish diagnoses for each fossil species based on

type material and make them as detailed and

reliable as possible. I hope that this will help to

more accurate secondary references in future in-

vestigations.

Discussion: The otolith morphologies found in

the genus Arnoglossus are quite diverse. Accord-

ing to NORMAN (1934) this also seems to be the

case for the fishes themselves which in the past

has led some authors to subdivide Arnoglossus

into more genera or subgenera. NORMAN stat-

ed that “the genus Arnoglossus still remains a

somewhat heterogenous group, but I (NORMAN)

am unable to find any valid reasons for its fur-

ther subdivision”. Results from otolith analyses

are similar. Some species morphologically are

more different from the “core” of the genus, such

as A. rueppellii, A. capensis, A. tapeinosoma or A. dal-

gleishi, but overall the patterns are to mosaic in

nature to warrant their separation from Arno-

glossus based on otoliths alone. It seems, howev-

er, that the European and East Atlantic species

(except for A. rueppellii) form a cluster of species

and the Indo-Pacific ones one or two other clus-

ters (for discussions see entries to species). In dif-

ferentiating the two main clusters the degree of

sulcal inclination could become a valuable char-

acter.

Otoliths of Arnoglossus resemble those of the

other genera in the group and differentiation on

the generic level is not always easy, even to gen-

167

Piscium Catalogus, Part Otolithi piscium, Vol. 2

era of presumably related otolith groups such as

Trichopsetta or Monolene of the Monolene-Laeops

Group. The most useful character for recognition

of Arnoglossus otoliths probably is the combina-

tion of the rather regularly rectangular outline

and the inclined sulcus.

Species and distribution: According to NOR-

MAN (1934) and HENSLEY (1986) there may be

some 19 to 24 recent species in the genus (exclud-

ing the species placed in the genera Neolaeops,

Asterorhombus and Caulopsetta). The following list

containing 29 species may not be complete. 7 spe-

cies are recorded from European and African

waters – A. capensis, A. grohmanni, A. imperialis,

A. laterna, A. macrostoma, A. rueppellii and A. thori

– and 22 from the Indo-West-Pacific and South-

ern Ocean – A.andrewsi, A. arabicus, A. armstrongi,

A. aspilos, A. bassensis, A. dalgleishi, A. debilis,

A. elongatus, A. fisoni, A. japonicus, A. kotthausi,

A. maculipinnis, A. marisrubri, A. muelleri, A. mul-

tirastris, A. oxyrhynchus, A. polyspilus, A. profundus,

A. sayaensis, A. tapeinosoma, A. tenuis and A. waitei.

Otoliths are known from 12 species. 2 recent spe-

cies are also known as fossils from the Pliocene of

the North Sea Basin – A. laterna and A. imperialis.

In addition there are 10 valid otolith based fossil

species of Arnoglossus ranging in age from Eocene

to Pliocene – 6 species from Europe and North

Africa (A. kokeni, A. lapierrei, A. holleri, A. prudhom-

mae, A. quadratus, A. taureri) and 4 from New Zea-

land (A. extremus, A. grenfelli, A. longus, A. novus).

Arnoglossus laterna (WALBAUM 1792)

Figs. 328-332

syn. Pleuronectes arnoglossus SCHNEIDER 1801

syn. Pleuronectes diaphanus SHAW 1803

syn. Pleuronectes leotardi RISSO 1810

syn. Rhombus nudus CUVIER 1817

syn. Pleuronectes conspersus CANESTRINI 1862

syn. Arnoglossus laterna microstoma KYLE 1913

Investigated otoliths: 5 otoliths, 2 otoliths (right

and left side, figs. 328-329) from the North Sea,

ZMH Ot. 16.5.1994.13-14 (coll. Schwarzhans), 1

otolith (right side, fig. 330) Bretagne, France, ZMH

Ot. 16.5.1994.15 (leg. FBH), 2 otoliths (right and

left side) from the Mediterranean, SMF 7620, 2

otoliths (figs. 331-332) from the Lower Pliocene

(Katendijkian) of Antwerp, Belgium, coll.

SCHWARZHANS.

Variability: Otoliths of A. laterna have been fig-

ured during several occasions, the most complete

Figs. 328-332: Arnoglossus laterna (WALBAUM 1792) – 15 ×

329

328b

328a

330b

328c

330a

331

332

168

Schwarzhans: Pleuronectiformes

series being the one of CHAINE (1936). The spe-

cies is well known for its rather large degree of

intraspecific variations. Features of the outline

and otolith proportions are heavily affected. Ex-

treme phenotypes, when isolated, may not always

be distinguishable from those of related species

such as A. thori or A. imperialis. However, the lack

of differentiation between A. laterna and A. mac-

rostoma in many collections and in literature as

well may well play a part in what seems to be an

overly variability spectrum. In any case, the range

of variations seen in such a well known species

as A. laterna should be kept in mind when deal-

ing with fossil otoliths of this genus.

Discussion: Otoliths of A. laterna exactly look like

“the average Arnoglossus otolith” to which many

of the other species, particularly from Europe and

North Africa, are traditionally being compared to.

Distribution: Eastern Atlantic, from Middle

Norway to Cape Blanc (Mauritania) and through-

out the Mediterranean. Also known as fossils from

the Pliocene of Belgium.

Arnoglossus macrostoma KYLE 1913

Figs. 333-334

Investigated otoliths: 2 otoliths (right side) from

off Dalmatian, Mediterranean, ZMH Ot.

16.5.1994.16 (leg. BMNH 93.2.28.29-30) and

BMNH 93.2.28.29-30.

Variability: One of the two specimens is more

thickset, the other one shows a slightly undulat-

ing ventral rim.

Discussion: In most ichthyological literature

A. macrostoma is regarded as a junior synonym of

A. laterna. NORMAN (1934) discussed this aspect

and gave his reasoning why he selected to regard

it as a separate species. After having extracted

otoliths from specimens identified by him as

A. macrostoma it seems that otoliths are somewhat

different from those of “typical” A. laterna speci-

mens as well. They are somewhat more elongate

and more rounded in outline. It appears that part

of the unusually high degree of intraspecific var-

iability reported for otoliths of A. laterna may be

due to lack of differentiation of the two species.

Distribution: Restricted to the Mediterranean.

Arnoglossus thori KYLE 1913

Fig. 335

syn. Arnoglossus moltoni TORCHIO 1961

Investigated otoliths: 6 otoliths (4 right and 2

left) from the Adriatic coast of Italy, ZMH Ot.

2.1.1995.18 (leg. BMNH 90.1.21.69-78) and BMNH

90.1.21.69-78.

Discussion: From the specimens extracted from

the BMNH collection only the one figured is well

preserved. Also judging from BAUZA-RUL-

Figs. 333-334: Arnoglossus macrostoma KYLE 1913 – 15 ×

333b

334a

333a

334b

169

Piscium Catalogus, Part Otolithi piscium, Vol. 2

LAN’s (1957) figures otoliths of A. thori are quite

similar to those of A. grohmanni or A. imperialis,

all three being species with rather elongate oto-

liths. Those of A. thori usually show some kind of

an irregularly undulating dorsal rim, often with

a notch at the posterior tip of the otolith, and an

obtuse midventral angle. However, I doubt that

the three species can always be distinguished

reliably by means of otoliths.

Distribution: Western Mediterranean and East

Atlantic, from Ireland to southernmost Morocco.

Arnoglossus grohmanni (BONAPARTE 1837)

Fig. 336

syn. Arnoglossus kessleri SCHMIDT 1915

Investigated otoliths: 1 otolith (right side) from

the Adria, Yugoslavia, SMF 13100.

Discussion: Larger series of this species have

been figured by CHAINE (1936) and BAUZA-

RULLAN (1957). From this it seems that the oto-

liths of A. grohmanni are the most elongate to be

found in Arnoglossus. However, this remains the

only character to distinguish the species from

A. imperialis. A certain degree of overlap appar-

ently exists and I doubt that the two species will

always be distinguishable by means of otoliths.

Distribution: Mediterranean and Black Sea.

Arnoglossus imperialis RAFINESQUE 1810

Figs. 337-339

syn. Arnoglossus lophotes GÜNTHER 1862

?syn. Arnoglossus blachei STAUCH 1965 (acc. to

HENSLEY, 1986)

Investigated otoliths: 6 otoliths, 3 otoliths (right

side, fig. 337-338) from Great Britain, ZMH Ot.

16.5.1994.17-18 (leg. BMNH 92.10.11.3-5) and

BMNH 92.10.11.3-5, 2 otoliths (right and left side)

from the Scyllies, ZMH Ot. 16.5.1994.19 (leg. SMF

15885) and SMF 15885, 1 eroded otolith (ident. as

A. blachei), 07°29’N/13°38’W, BMNH 1962.6.18.

36-45; 1 otolith (fig. 339) from the Lower Pliocene

(Katendijkian) of Antwerp, Belgium.

Ontogeny and variability: The outline of the

otoliths of this species is rather constant, but the

length to height ratio seems to be quite variable.

Also larger specimens are continuously becom-

ing more elongate.

Discussion: A. imperialis is one of the European

species of Arnoglossus with rather elongate oto-

liths, like A. macrostoma, A. thori and A. grohmanni.

Seemingly they are the ones with the most regu-

lar rectangular outline and they do not seem to

become as elongate as the ones of A. grohmanni.

Nevertheless, distinction of otoliths of these spe-

cies may not always be possible, in particular

when dealing with isolated specimens. A single

eroded specimen extracted from a fish identified

as A. blachei was too much eroded to be figured.

Its general appearance, however, confirms HENS-

LEY’s (1986, in SMITH & HEEMSTRA) view of

this species representing a junior synonym of

A. imperialis.

Together with the three species mentioned

above and A. laterna A. imperialis seems to form a

cluster of species within the genus Arnoglossus.

All these species are remarkable for their rela-

tively flat inner face and the rather low degree of

inclination of the sulcus. In addition, there are

certain fossil species from the same geographic

area which also seem to fit within this cluster.

They are described in the following – A. holleri,

A. taureri, A. kokeni and A. quadratus.

Distribution: Western Mediterranean and East

Atlantic, from Scotland southward to Angola.

Arnoglossus holleri WEINFURTER 1952

Figs. 341-352

syn. Arnoglossus holleri WEINFURTER 1952 –

WEINFURTER 1952: pl. 4, fig. 4

syn. Arnoglossus miocenicus WEILER 1962 –

WEILER 1962: fig. 1, 18a-20

syn. Arnoglossus miocenicus – STEURBAUT 1979:

pl. 11, fig. 12-14

?syn. Arnoglossus sp. – NOLF & CAPPETTA 1980:

pl. 3, fig. 15-16

syn. Arnoglossus sp. STEURBAUT & JONET

1981: pl. 4, fig. 6

syn. Arnoglossus sp. – STEURBAUT 1984: pl. 34,

fig. 17-22

syn. Arnoglossus sp.2 – RADWANSKA 1992:

fig. 158, pl. 38, fig. 1-3

170

Schwarzhans: Pleuronectiformes

Investigated otoliths: About 50 otoliths, figured

specimens are: holotype of A. holleri (fig. 341),

Badenian, Middle Miocene, Wetzelsdorf in Graz

Basin, Austria (LMJ); 1 otolith (fig. 342), Badeni-

an of Sooß, Vienna Basin, Austria (coll.

Schwarzhans); 5 otoliths (figs. 343-346), Badeni-

an, Middle Miocene, Korytnica, Poland

(ZPalUW/Rak 434, 435, 437); 6 otoliths (figs. 347-

349), Burdigalian, Lower Miocene, Costa di Ca-

parica near Lisbon, Portugal (coll. Schwarzhans);

3 otoliths (figs. 350-352), Hemmoorian and Rein-

bekian, Lower to Middle Miocene, well Lüllingen,

NW-Germany (coll. Wienrich).

Fig. 335: Arnoglossus thori KYLE 1913 – 15 ×

Fig. 336: Arnoglossus grohmanni (BONAPARTE 1837) – 15 ×

Figs. 337-339: Arnoglossus imperialis RAFINESQUE 1810 – 15 ×

Fig. 340: Arnoglossus capensis BOULANGER 1898 – 15 ×

335a

337b

336

338

335b

339a

337a

339b

340b

340a

340c

171

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ontogeny and variability: This is a relatively

small species. Diagnostic maturity seems to be

reached with otoliths of about 1.5 mm length.

Smaller otoliths are extremely generalized and

can only be identified in the context of sufficient

ontogenetical sequences.

Variability is rather moderate, mainly concern-

ing details of the outline and otolith proportions.

Discussion: These small otoliths are relatively

compressed and somewhat “roundish” in outline.

Otherwise they are similar to the recent A. laterna

and the parallelly occurring A. taureri. The indis-

tinct, roundish appearance and the small size of

the otoliths has led otolith specialists in previous

publications to regard them as some kind of un-

identifiable juvenile forms. This interpretation is

tempting, of course, but now that a large series of

specimens is available it becomes obvious that

they rather represent a small species. Neverthe-

less, it may at times become difficult to distin-

guish A. holleri from juveniles of other species,

particularly so in isolated findings. – The type-

specimens of WEILER’s A. miocenicus from the

Middle Miocene of the North Sea Basin has not

been available for review. However, newly col-

lected material from the same area and strata (figs.

350-352) prove that this nominal species should

be regarded as a junior synonym of A. holleri.

Distribution: Lower and Middle Miocene of the

Paratethys (Poland and Austria), the European

Atlantic Basins (Portugal and western France) and

the North Sea Basin (NW-Germany).

Arnoglossus taureri (WEINFURTER 1952)

Figs. 353-359

syn. Solea taureri WEINFURTER 1952 – WEIN-

FURTER 1952: pl. 2, fig. 12-13

syn. Solea aff. taureri – SMIGIELSKA 1966: pl. 15,

fig. 10-11

syn. Arnoglossus inconspectus SMIGIELSKA

1973 – SMIGIELSKA 1973: pl. 5, fig. 10

syn. Arnoglossus sp. – STEURBAUT & JONET

1981: pl. 4, fig. 5

syn. Arnoglossus aff. laterna – RADWANSKA 1992:

fig. 156, pl. 36, fig. 8-10

syn. Arnoglossus sp.1 – RADWANSKA 1992:

fig. 157, pl. 36, fig. 11

Investigated otoliths: About 30 otoliths, figured

specimens are: 3 otoliths (figs. 353-355), Badeni-

an, Middle Miocene, Niskowa, southern Poland

(ZPalUW/RaNi 430, 431, 432); 5 otoliths (figs. 356-

359), Burdigalian, Lower Miocene, Costa di Ca-

parica near Lisbon, Portugal (coll. Schwarzhans).

Ontogeny and variability: Like A. holleri, A. tau-

reri too is a rather small species with compressed

otoliths. But in this case even very small speci-

mens of about 1.2 to 1.5 mm can be identified

due to their characteristic outline. Variability too

is moderate in this species, however, erosive ef-

fects need to be taken into account as well.

Discussion: A. taureri is rather easily recognized

by its pronounced rectangular outline. Charac-

teristically, the posterior portion of the otolith is

much higher than the anterior portion. This ef-

fect is caused by the very strong and sharp post-

dorsal and postventral angles.

Distribution: A. taureri occurs parallelly to

A. holleri in the Lower and Middle Miocene of the

Paratethys (Poland and Austria) and the Europe-

an Atlantic Basins (Portugal and possibly also

western France). It is missing from the North Sea

Basin.

Arnoglossus kokeni (BASSOLI 1906)

Figs. 360-364

syn. Solea kokeni BASSOLI 1906 – BASSOLI 1906:

pl. 2, fig. 3

syn. Arnoglossus bauzai SANZ ECHEVERRIA

1950 – SANZ ECHEVERRIA 1950: pl. 55,

fig. 1.3

syn.

Arnoglossus bauzai – BAUZA-RULLAN 1964:

pl. 4, fig. 4

syn. Arnoglossus laterna – ANFOSSI & MOSNA

1973: pl. 12, fig. 11-13

syn. Arnoglossus bauzai – NOLF & MARTINELL

1980: pl. 5, fig. 26-29

syn. Arnoglossus kokeni – NOLF & STEURBAUT

1983: pl. 7, fig. 24

Investigated otoliths: 10 otoliths; the holotype

of A. kokeni (fig. 360), Tortonian, Upper Miocene,

Montegibbio, Toscana, Italy (IPUM 16628); 9 oto-

liths (figs. 361-364), Lower Pliocene, Dar Bel

Hamri, NW-Morocco (coll. Schwarzhans).

172

Schwarzhans: Pleuronectiformes

Figs. 341-352: Arnoglossus holleri WEINFURTER 1952 – 15 ×

Figs. 353-359: Arnoglossus taureri (WEINFURTER 1952) – 15 ×

341a

343c

342

341b

341c

346

343a

343b

354

353b

350c

345

349

347

344

350a

352

350b

351

348

353a

355c

355b

355a

358

357

356

359

173

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ontogeny and variability: Specimens smaller

than 1.5 mm are more roundish in outline than

those up to 2.2 mm. Otherwise, the otoliths of

this species seem to be rather constant, even as

far as the outline is concerned.

Discussion: This are typical compact otoliths

with a regular rectangular outline. In many ways

they are similar to the recent A. laterna. However,

otoliths of A. kokeni are almost always more com-

pressed and more thickset. (It is interesting to

note that the recent A. laterna occurred simulta-

neously in the Lower Pliocene of the North Sea

Basin.) However, separation of the two species

may not be possible in all instances. In the Lower

Pliocene of NW-Morocco a second Arnoglossus

species occurs parallelly – A. quadratus – which is

similar in outline and habitus, but more elongate

and even more thickset.

Distribution: Upper Miocene of Italy, Lower

Pliocene of Morocco, southern France and Spain.

Arnoglossus quadratus n.sp.

Figs. 365-373

Name: quadratus (lat.) = rectangular, referring

to the outline of the otolith.

Holotype: Fig. 365, SMF P 9317.

Type-locality: Right river banks of the Oued Beth,

ca. 1 km south of Dar Bel Hamri, NW-Morocco.

Age: Lumachelle at the base of the Sands of Dar

Bel Hamri, Lower Pliocene.

Paratypes: 11 otoliths (figs. 366-373), topo- and

stratitypic, SMF P 9318.

Diagnosis: Moderately elongate, very massive

and thickset otoliths up to 2.5 mm, with a regular

rectangular outline. Inner face flat in adults, con-

vex in juveniles. Sulcus moderately wide and

deep, inclined at an angle of about 5 to 10°.

Description (of adults): Outline: Moderately

elongate, massive and very thickset otoliths with

a regularly rectangular outline. Dorsal and ven-

tral rims nearly straight, flat and horizontal.

Anterior and posterior tips vertically cut. All rims

smooth.

Inner face: Flat in the horizontal and slightly

convex in the vertical direction, rather smooth.

Sulcus rather wide, moderately deep and anteri-

orly inclined at an angle of 5 to 10°. Sulcus opening

somewhat reduced. Ostium and cauda clearly

separated, ostium considerably longer and wider

than cauda. Dorsal and ventral depressions wide,

moderately deep, with indistinct boundaries,

more or less connected around the caudal tip.

Figs. 360-364: Arnoglossus kokeni (BASSOLI 1906) – 15 ×

360c

360b

360a

361c

364b

361a

361b

363

362

364a

174

Schwarzhans: Pleuronectiformes

Other views: Otolith rims rather thickset,

smooth. Outer face convex, smooth.

Ontogeny and Variability: A. quadratus shows a

very pronounced allometric ontogenetic change.

Otoliths smaller than 1.8 mm in length are more

compressed, show a more regularly rounded,

somewhat undulating outline, a much more con-

vex inner face and a narrower sulcus. Few spec-

imens are intermediate in size and morphology

(figs. 367-369) proving that both morphotypes

indeed represent ontogenetic stages of a single

species and not two separate species which could

also have been assumed. This fact once more

exemplifies that specific identification based on

juvenile or subadult otoliths alone can be quite

misleading and that establishing of new fossil spe-

cies should be avoided to be based on such forms.

Intraspecific variability on the other hand is

much less prominent within the two ontogenetic

categories. The smaller otoliths, however, are

more apt to slight variations in the expression of

the outline.

Side dimorphism: Not apparent.

Discussion: A, quadratus is quite similar to

A. kokeni with which it occurs simultaneously in

northern Morocco (but not elsewhere). It differs

in being somewhat more elongate and consider-

ably more thickset. Also the index ol:cl is lesser

and in adults the ostium is more widened as

compared to the cauda. A. laterna, which is sim-

ilar too, has much more thin otoliths and a higher

index ol:cl (just like A. kokeni).

Arnoglossus capensis BOULANGER 1898

Fig. 340

?syn. Arnoglossus entomorhynchus STAUCH 1967

(acc. to HENSLEY, 1986)

Investigated otoliths: 1 otolith (left side) from

Gough Island, Central South Atlantic, west of

South Africa, BMNH 1957.9.4.1.

Figs. 365-373: Arnoglossus quadratus n.sp. – 15 ×

365c

366b

366a

367

365a

365b

368

371a

370

369

372a

373

372b

371b

175

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: A. capensis differs from the other

European and African species at the genus in the

more regularly rounded elongate shape, the dis-

tinctly convex inner face and the ostial opening

of the very deep sulcus. With this pattern it stands

somewhat apart from all the other species of the

genus. In fact, the general appearance is more

like the species of the closely related genus Cau-

lopsetta, an endemic New Zealandian genus.

Distribution: Coasts of South Africa. The speci-

men from which the otolith was extracted origi-

nates from the Gough Island, an isolated central

South Atlantic Island located at considerable dis-

tance from the African continent.

Arnoglossus rueppellii (COCCO 1844)

Fig. 374

syn. Bascanius taedifer SCHIODTE 1868

Investigated otoliths: 3 otoliths (2 right side; 1

left side, fig. ) from off Sardinia, Mediterranean,

ZMH Ot. 17.6.1994.1-3 (leg. ZMUC 853172-76).

Discussion: A. rueppellii is the first of a series of

species with strongly inclined sulci. Sulcus incli-

nation is in the order of 20-25°. Within this group

it is the only one from the East Atlantic/Mediter-

ranean, all the others originating from the Indo-

Pacific. A. rueppellii is remarkable for its very short

cauda and the oblique, dorsally projecting poste-

rior rim.

Distribution: Western Mediterranean and Adria-

tic and East Atlantic, from the Strait of Gibraltar

to southern Morocco, in rather deep water (200-

550 m).

Arnoglossus tapeinosoma (BLEEKER 1866)

Figs. 375-376

syn. Arnoglossus macrolophus ALCOCK 1889

Investigated otoliths: 3 otoliths (2 right side and

1 left side) from the Gulf of Oman, ZMH Ot.

17.5.1994.4-5 (leg. BMNH 1939.5.24.1718-20) and

BMNH 1939.5.24.1718-20.

Discussion: Similar to A. rueppellii in many as-

pects, including the oblique, dorsally projecting

Fig. 374: Arnoglossus rueppellii (COCCO 1844) – 15 ×

Figs. 375-376: Arnoglossus tapeinosoma (BLEEKER 1866) – 15 ×

Fig. 377: Arnoglossus waitei NORMAN 1926 – 15 ×

Fig. 378: Arnoglossus aspilos (BLEEKER 1851) – 15 ×

376c

377b

374a

377a

376a

378b

376a

378a

375

176

Schwarzhans: Pleuronectiformes

posterior rim. However, otoliths of A. tapeinosoma

are more compressed and show a distinctive

middorsal concavity.

Distribution: Indo-West-Pacific, from the Persian

Gulf to the Malay Peninsula and Indonesia.

Arnoglossus waitei NORMAN 1926

Fig. 377

Investigated otoliths: 1 otolith (right side) from

the Arafura Sea, Indonesia, BMNH 79.5.14.59-60.

Discussion: A. waitei shows a more regular rec-

tangular outline than A. rueppellii or A. tapeino-

soma and the sulcus is less steeply inclined (about

10°). More similar in this respect is A. aspilos, but

these otoliths are more compressed.

Distribution: Arafura Sea and east coast of

Queensland.

Arnoglossus aspilos (BLEEKER 1851)

Fig. 378

Investigated otoliths: 1 otolith ( right side) from

Singapore, ZMH Ot. 17.5.1994.6 (leg. ZMH 19883).

Discussion: Similar to A. waitei, but more com-

pressed.

Distribution: Malay Peninsula and Indonesia.

Arnoglossus lapierrei (NOLF 1988)

Fig. 379 (381-382)

syn. genus Bothidarum lapierrei NOLF 1988 –

NOLF 1988: pl. 14, fig. 9 (non figs. 10-11).

Investigated otoliths: NOLF’s holotype (fig. 379;

IRSNB P 4522) and his 2 paratypes (figs. 381-382;

IRSNB P 4523-4524) from the tuillerie de Gan near

Pau, Aquitaine Basin, SW-France, Clays of Gan,

Ypresian, Lower Eocene, IRSNB.

Fig. 379: Arnoglossus lapierri (NOLF 1988) – 15 ×

Fig. 380: Arnoglossus prudhommae (STEURBAUT 1984) – 15 ×

Figs. 381-382: Pleuroenctiformes indet. (Paratypes of Arnoglossus lapierri) – 15 ×

380c

381c

379c

379b

380a

382

380b

381a

379a

381b

177

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: A. lapierrei is one of the fossil spe-

cies with a steeply inclined sulcus and it is the

oldest record of the genus. Otoliths are moder-

ately compressed, rather thickset, with a rectan-

gular outline and a clear sulcus opening.

Remarks: NOLF (1988) also placed two addition-

al specimens in this species (as paratypes). A re-

view of those specimens (see figs. 381-382) indi-

cates that they represent quite a different species

and may be genus altogether (possibly a plesio-

morphic fossil genus of some Bothidae). These

otoliths are more thin, with a very characteristic

and quite different outline and dorsal and ven-

tral depressions (the latter with a very special

outline) are clearly disconnected behind the cau-

da. Nolf has informed me that more material from

this location is being expected soon. Therefore, I

have refrained from establishing a new species

based on this little material. Anyway, only the

unique holotype is at present regarded as a valid

record of A. lapierrei.

Distribution: Lower Eocene of SW-France.

Arnoglossus prudhommae (STEURBAUT 1984)

Fig. 380

syn. Monolene prudhommae STEURBAUT 1984 –

STEURBAUT 1984: pl. 34, fig. 26-27.

Investigated otoliths: 1 paratype from Moulin

d’Yrieu, Aquitaine Basin, SW-France, Sands of

Yrieu, Lower Oligocene, IRSNB P 4240.

Variability: According to the figures of STEUR-

BAUT (1984) the holotype is slightly larger and

shows some faint crenulation of the dorsal rim.

Discussion: A. prudhommae is very similar to

A. lapierrei, but considerably more compressed.

The strong inclination of the sulcus (25°) charac-

terize both species as representatives of the ge-

nus Arnoglossus.

Distribution: Lower Oligocene of the Aquitaine

Basin, SW-France.

Arnoglossus extremus SCHWARZHANS 1980

Fig. 383

syn. Arnoglossus extremus SCHWARZHANS

1980 – SCHWARZHANS 1980: fig. 576

Investigated otoliths: The unique holotype from

McCullough’s Bridge (GS 9508), Canterbury, New

Zealand South Island, Kaiatan, Upper Eocene,

NZGS.

Discussion: A. extremus closely resembles the

two Early Tertiary species of Europe – A. lapierrei

and A. prudhommae. It is recognized by its slight-

ly more elongate shape and an index ol:cl of about

1.0.

Distribution: Upper Eocene of New Zealand.

Arnoglossus longus SCHWARZHANS 1980

Figs. 384-394

syn. Arnoglossus longus SCHWARZHANS 1980 –

SCHWARZHANS 1980: fig. 577-578

syn. Arnoglossus novus – GRENFELL 1984:

fig. 107-108, 214-216

Investigated otoliths: 69 otoliths, the holotype

(fig. 386) and 1 paratype (fig. 385) from Pukeuri

(GS 9685), Otago, New Zealand South Island,

Altonian, Lower Miocene; 1 paratype from Waiau

river (GS 1228), Clifden, Southland, New Zea-

land South Island, Altonian, Lower Miocene; 1

paratype from Otekaike (GS 9517), Otago, New

Zealand South Island, Waitakian, Upper Oli-

gocene, all NZGS; 2 otoliths (fig. 384) from Suth-

erland, Otago and 1 otolith from Pukeuri, both

Altonian, Lower Miocene, coll. Richardson; 57

otoliths (figs. 387-392) from the Pareora River,

Otago, Waitakian, Upper Oligocene and 5 oto-

liths (figs. 393-394) from Chatton, Otago, Dun-

troonian, Middle Oligocene, coll. Maxwell.

Fig. 383: Arnoglossus extremus

SCHWARZHANS 1980 – 25 ×

178

Schwarzhans: Pleuronectiformes

Ontogeny and variability: Small otoliths

(>1.2 mm) may not always be distinguishable

from those of A. novus, whereas in adult otoliths

this is not at all problematical. A series of small

otoliths collected from the Upper and Middle

Oligocene, a time when only A. longus was

present, show a more compressed and rounded

outline with somewhat undulating rims (figs. 387-

394). Juveniles of A. novus seem to have a more

regular, smooth outline. Large otoliths show a

certain variation in otolith and sulcus proportions

and details of the outline.

Discussion: See entry to A. novus.

Distribution: Middle Oligocene to Lower Mio-

cene of New Zealand.

Arnoglossus novus SCHWARZHANS 1980

Figs. 395-397

syn. Arnoglossus novus SCHWARZHANS 1980 –

SCHWARZHANS 1980: fig. 579-580

Investigated otoliths: 11 otoliths, the holotype

(fig. 395) and 4 paratypes (fig. 396) from Pukeuri

(GS 9685), Otago, New Zealand South Island,

Altonian, Lower Miocene; 1 paratype from Weka

Creek (GS 9567), Canterbury, New Zealand South

Island, Altonian, Lower Miocene; 4 paratypes

from Masterton near Wellington, New Zealand

North Island, Waiauan, Middle Miocene, all

NZGS; 1 otolith (fig. 397) from Pukeuri, coll. Ri-

chardson.

Ontogeny and variability: Small otoliths of less

than 1.0 to 1.5 mm show a much more rounded

outline and in fact are so generalized that they

Figs. 384-394: Arnoglossus longus SCHWARZHANS 1980 – figs. 384-385, 387-394 = 15 ×; fig. 386 = 25 ×

386

387

384a

384b

389

394

388b

393

385

390

391

388a

388c

392

179

Piscium Catalogus, Part Otolithi piscium, Vol. 2

can not be reliably distinguished from the paral-

lelly occurring A. longus. Adult otoliths do not

show much variability at all, except for some

variations of the sulcus proportions.

Discussion: A rather compressed, massive oto-

lith with a rectangular outline and very deep

sulcus and dorsal and ventral depressions. The

inclination of the sulcus is steep, about 25°. From

the parallelly occurring A. longus it is easily dis-

tinguished by its more compressed shape, the

steeply inclined sulcus and the deep morpholo-

gy of the inner face.

Distribution: Lower and Middle Miocene of

New Zealand.

Arnoglossus grenfelli n.sp.

Figs. 398-399

Name: In honor of H. Grenfell (Auckland) and

his fine work on fossil otoliths from the North

Island of New Zealand.

Holotype: Fig. 398, BSP 1984 X 114.

Type-locality: Martinborough, New Zealand

North Island.

Age: Wanganuian, Lower Pliocene.

Paratypes: 1 otolith (fig. 399), topo- and strati-

typic, BSP 1984 X 115.

Diagnosis: Moderately elongate and massive

otoliths with rectangular outline. Anteriorly with

incipient rostrum. Otolith rims slightly undulat-

ing. Inclination of sulcus moderate (10°).

Figs. 395-397: Arnoglossus novus SCHWARZHANS 1980 – figs. 395-396 = 25 ×; fig. 397 = 15 ×

Figs. 398-399: Arnoglossus grenfelli n.sp. – 15 ×

396

399a

398a

397b

395

399b

398b

397a

397c

398c

180

Schwarzhans: Pleuronectiformes

Description: Outline: Moderately elongate and

massive otoliths with a typical rectangular out-

line. Dorsal rim straight, horizontal, with prom-

inent pre-and postdorsal angles, the latter being

more pronounced. Ventral rim flat, slightly curv-

ing. Posterior rim vertically cut to slightly ob-

lique, then dorsally projecting. Anterior tip ob-

lique, with incipient rostrum. All rims slightly

undulating.

Inner face: Slightly to moderately convex,

with a narrow, moderately deep, slightly inclined

sulcus (10°). Sulcus opening ostial to very slight-

ly reduced. Ostium and cauda clearly separated,

ostium longer, but not much wider than cauda.

Dorsal and ventral depressions wide, moderate-

ly deep, connected around the caudal tip.

Other views: Otolith rims moderately thick-

set, slightly undulating. Outer face slightly to

moderately convex, rather smooth.

Side dimorphism: An incipient side dimorphism

seems to be present in this species. The left hand

otolith shows a more convex inner face than the

right hand otolith.

Discussion: A. grenfelli resembles the European

A. laterna, but is more thickset and shows a smaller

index ol:cl. Other Arnoglossus species of the re-

gion, fossil or recent, do not much resemble

A. grenfelli.

Arnoglossus debilis (GILBERT 1905)

Fig. 400

Investigated otoliths: 1 otolith (right side) from

Hawaii, BMNH 1931.8.19.3.

Discussion: The otoliths of A. debilis are quite

inconspicuous morphologically. They show a

compressed, rounded rectangular shape and a

not very steeply inclined sulcus (10°). The inner

face is relatively flat and the otolith rather thin. In

these aspects A. debilis resembles closest A. dal-

gleishi.

Distribution: Hawaiian Islands, in rather deep

water.

Arnoglossus dalgleishi (VON BONDE 1922)

Figs. 401-402

Investigated otoliths: 4 otoliths (3 right side and

1 left side) from off Zanzibar, ZMH Ot. 17.5.1994.7-

9 (leg. BMNH 1939.5.24.1731-34) and BMNH

1939.5.24.1731-34.

Variability: The otoliths of this species seem to

be quite constant morphologically.

Discussion: A. dalgleishi resembles A. debilis in

the rather thin appearance, the flat inner face and

the low inclination angle of the sulcus. These two

species probably form the core of still another

cluster of Arnoglossus species to which NORMAN

(1934) has assigned the name Anticitharus in sub-

generic ranking. A. dalgleishi differs from A. debilis

in the more rounded and conspicuously undulat-

ed otolith rims and in the reduction of the ante-

rior part of the ostial colliculum.

Distribution: South and East Africa.

Fig. 400: Arnoglossus debilis (GILBERT 1905) – 15 ×

181

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Caulopsetta GILL 1893

Type-species: Pleuronectes scapha SCHNEIDER

1801

Diagnosis: Moderately thick and relatively large

otoliths with a rounded rectangular outline; ven-

tral rim shallow, gently curved, dorsal rim shal-

low too, with rounded pre-and postdorsal an-

gles, posterior tip blunt, nearly vertically cut,

sometimes with deep notch, anterior rim blunt,

with incipient short rostrum, but without excisu-

ra; index l:h 1.4 to 1.6. Otolith size up to 6 mm.

Ostium much longer than cauda and slightly

wider too. Sulcus narrow, moderately deep, very

slightly inclined, with a slightly reduced ostial

opening. Cauda terminating relatively close to

posterior tip of otolith. Separation of colliculi

variable. Dorsal and ventral depressions deep,

sharp and well marked, not completely connect-

ed around caudal tip to form a circumsulcal de-

pression.

Inner face moderately convex, not smooth;

outer face flat to slightly convex, usually smooth.

Rims sharp, sometimes slightly undulating.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

scapha 1.40-1.60 2.7 1.45-1.65 1.1-1.4 5° 5.5

+arnoglossoides 1.15-1.30 3.0 1.7-1.9 1.0-1.3 5-10° 3.0

Side dimorphism: The recent C. scapha exhibits

some obvious side dimorphism in the morphol-

ogy of the posterior rim of the otolith. In left hand

specimens it is blunt, vertically cut. In right hand

specimens the posterior rim is distinctly concave,

sometimes deeply incised, with the postdorsal

part being expanded and the postventral part

projecting backwards. In the fossil C. arnoglos-

soides side dimorphism is similarly developed,

but less pronounced.

Ontogeny: Smaller specimens tend to be more

compressed than adult ones, sometimes also be-

ing crenulated along the rims.

Discussion: Caulopsetta no doubt is closely relat-

ed to Arnoglossus. In fact, NORMAN (1934) did

place Caulopsetta in the synonymy of the latter.

Otoliths, however, differ in certain aspects from

“typical” Arnoglossus species, thus warranting in

my opinion the separation of the genus. Caulopset-

ta otoliths are larger, show a more regularly elon-

gate outline, a low inclination angle of the sulcus

and an incomplete connection of the dorsal and

ventral depressions around the cauda. In a way

this otolith pattern could be interpreted as plesi-

omorphic in comparison to the one found in

Arnoglossus. Within Arnoglossus there is one spe-

cies that stands somewhat apart from the rest

402a

401

402b

Figs. 401-402: Arnoglossus dalgleishi (VON BONDE 1922) – 15 ×

182

Schwarzhans: Pleuronectiformes

and resembles Caulopsetta most – A. capensis (see

also respective entry). May be this indicates that

the dividing line between Arnoglossus and Cau-

lopsetta needs to be revised somewhat.

Species and distribution: Two recent species

endemic to New Zealand – C. scapha and C. boops–

and one fossil species from the Lower Miocene of

New Zealand – C. arnoglossoides.

Caulopsetta scapha

Figs. 403-406

syn. Pseudorhombus hectoris GÜNTHER 1887

Investigated otoliths: 6 otoliths, 4 otoliths (2 right

side and 2 left side, figs. 403-404) from off

Christchurch, New Zealand, ZMH Ot. 23.5.1994.1-

3 (leg. BMNH 1930.12.30.1-3) and BMNH

1930.12.30.1-3, 2 otoliths from the paratypes of

C. hectoris (right side, figs. 405-406), Challenger

stat. 167, BMNH 90.2.26.155-6.

Side dimorphism: See entry to genus.

Discussion: The two otoliths from the paratypes

of C. hectoris perfectly fit with the other speci-

mens of C. scapha supporting NORMAN’s syno-

nymisation of the two species.

Distribution: Endemic to the coasts of New Zea-

land.

Caulopsetta arnoglossoides n.sp.

Figs. 407-411

Name: Referring to the similarity of these oto-

liths (particularly the juvenile ones) to the genus

Arnoglossus.

Holotype: Fig. 410, NZGS.

Type-locality: Ardgowan Shell Bed, Black Bridge,

Otago, New Zealand South Island.

Age: Altonian, Lower Miocene.

Paratypes: 1 otolith (fig. 411), topo- and stratit-

ypic; 3 otoliths (figs. 407-409) from Sutherlands

Cliffs, Lower Tengawai River, Canterbury, New

Zealand South Island; 2 otoliths from Clifden,

Waiau River, Southland, Altonian; 1 otolith from

Clelland road bridge, Tengawai River, Canterbury,

Otaian, Lower Miocene; all NZGS.

Diagnosis: Compressed, relatively thin otoliths

with deeply curved ventral and flat dorsal rim.

Posterior rim vertically cut or concave. Sulcus

slightly inclined, deep and long. Dorsal and ven-

tral depressions deep, well marked, incomplete-

ly connected around caudal tip.

Figs. 403-406: Caulopsetta scapha (BLOCH & SCHNEIDER 1801) – 10 ×

403c

404

403a

403b

405

406

183

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Description (of adults): Outline: Compressed,

rather thin otoliths, with deeply curved ventral

rim and rather flat, horizontal dorsal rim, with

rounded pre- and pronounced postdorsal angles.

Posterior tip concave (in right hand otoliths) or

vertically cut. Anterior tip blunt, but somewhat

pointed. All rims smooth.

Inner face: Moderately convex, not smooth.

Sulcus narrow, long, terminating close to the pos-

terior tip of the otolith, slightly inclined, deep.

Sulcus opening very slightly reduced. Ostium and

cauda separated, ostium considerably longer than

cauda, but only slightly wider. Dorsal and ven-

tral depressions deep, sharp, well marked, incom-

pletely connected around caudal tip.

Other views: Otolith rims sharp, smooth.

Outer face flat to slightly convex, practically

smooth.

Ontogeny: Most specimens are of relatively small

size and represent juvenile to subadult stages

except for the holotype and two paratypes which

are fully mature morphologically. The smaller

specimens (less than 2 mm) are more compressed

due to a more bluntly developed anterior tip and

also the sulcus sometimes is more steeply inclined.

The very smallest specimen of about 1.2 mm

(fig. 409) shows some marginal crenulation.

Side dimorphism: Like in the recent species,

otoliths of the right side exhibit a concave poste-

rior rim in adults, whereas in those of the left side

it is vertically cut.

Discussion: This is a “typical” species of the

genus Caulopsetta, differing from the recent C. sca-

pha in being more compressed and showing a

more deeply curved ventral rim. Juveniles, how-

ever, bear some resemblance to Arnoglossus oto-

liths in outline due to the more bluntly devel-

oped anterior tip. Two parallelly occurring spe-

cies of Arnoglossus – A. longus and A. novus – are

much more thickset with a rectangular outline of

the otolith. A. longus is also more elongate. Even

juveniles of C. arnoglossoides can reliably been

differentiated from these two species.

Figs. 407-411: Caulopsetta arnoglossoides n.sp. – 15 ×

407b

407a

409

410b

411

407c

410a

410c

408

184

Schwarzhans: Pleuronectiformes

Lophonectes GÜNTHER 1880

Type-species: Lophonectes gallus

syn. Lophorhombus MACLEAY 1883 (type-species:

Lophorhombus cristatus, syn. L. gallus)

Diagnosis: Relatively thickset otoliths with an

elongated, rounded outline; ventral rim shallow,

gently curved, dorsal rim also regularly curved,

with a faint and strongly rounded predorsal an-

gle, posterior tip rounded, anterior rim rounded,

with incipient short rostrum, but without excisu-

ra; index l:h 1.55-1.65. Otolith size slightly over

3 mm.

Ostium longer than cauda and slightly wider

too. Sulcus rather deep, very slightly inclined,

with a slightly reduced ostial opening. Cauda

terminating at moderate distance from posterior

tip of otolith. Colliculi well separated. Dorsal and

ventral depressions moderately deep and well

marked, more or less connected around caudal

tip to form a circumsulcal depression.

Inner face moderately convex, not very

smooth; outer face flat, rather smooth. Rims mod-

erately sharp, smooth.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

gallus 1.55-1.65 2.5 1.2-1.8 1.2-1.5 5° 3.2

Side dimorphism: Not apparent.

Variability: Variability within this species is

moderate, restricted to variations of the propor-

tions of the sulcus, expression of the predorsal

angle and thickness of the rims.

Discussion: The elongate otoliths of Lophonectes

with their regularly rounded outline and the rath-

er deep sulcus which is only slightly inclined

definitely resembles otoliths of the genus Cau-

lopsetta and of the species Arnoglossus capensis.

Species and distribution: Lophonectes is a mon-

ospecific genus with a single species – L. gallus –

from SE-Australia, Tasmania and New Zealand.

Lophonectes gallus GÜNTHER 1880

Fig. 412-414-A, 414-B

syn. Lophorhombus cristatus MACLEAY 1883

syn. Arnoglossus mongonuiensis REGAN 1914

Figs. 412-414-A, 414-B: Lophonectes gallus GÜNTHER 1880 – 15 ×

413b

413a

412

413c

414-A

414-B

185

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Investigated otoliths: 5 otoliths (4 right side and

1 left side) from Port Jackson, New South Wales,

Australia, ZMH Ot. 25.5.1994.2-5 (leg. BMNH

90.9.23.46-51) and BMNH 90.9.23.46-51.

Discussion and distribution: See entry to genus

(monospecific genus).

Psettina HUBBS 1915

Type-species: Engyprosopon iijimae JORDAN &

STARKS 1904

syn. Crossolepis NORMAN 1927 (type-species:

Arnoglossus brevirictis)

syn. Crossobothus FOWLER 1934 (type-species:

Bothus (Crossobothus) variegatus)

syn. Psettinella FEDOROV & FOROSHCHUK

1988 (type-species: N.N.)

Diagnosis: Relatively thick, massive, small oto-

liths with a rounded outline; ventral rim shallow,

regularly curved, dorsal rim curved or flat, then

with rounded pre-and postdorsal angles, poste-

rior tip blunt, rounded, anterior rim blunt, some-

times with incipient short rostrum, but without

excisura; index l:h 1.1-1.4. Otolith size up to 3 mm.

Ostium longer than cauda and considerably

wider. Sulcus wide, moderately deep, slightly

inclined, with a slightly reduced ostial opening.

Cauda terminating at moderate distance from

posterior tip of otolith. Colliculi well separated.

Dorsal and ventral depressions moderately deep

and well marked, connected around caudal tip to

form a circumsulcal depression.

Inner face slightly to moderately convex, not

very smooth; outer face slightly convex, smooth.

Rims thickset, smooth to slightly undulating.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

iijimae 1.15-1.25 2.2 1.3-1.5 1.3-1.5 5° 2.8

brevirictis 1.40 2.4 1.4 1.4 5° 3.7

Side dimorphism: Otoliths of the left side seem

to be more rounded in outline, which is particu-

larly relevant for the expression of the dorsal rim.

Also the colliculi are less well separated.

Discussion: Psettina is very close to Arnoglossus

(in accordance with NORMAN, 1934). In fact,

differentiation of the two genera based on oto-

liths alone may not always be possible. Psettina

otoliths are characterized by their roundish shape

and the rather wide ostium.

Species and distribution: At least 6 species from

the Indo-West-Pacific, usually in rather deep

water. Two species are known from India to the

Indo-Australian Archipelago – P. brevirictis and

P. profunda – and three species from Japan – P. ii-

jimae, P. gigantea, P. tosana and P. variegata. Oto-

liths are known from P. brevirictis and P. iijimae.

Psettina brevirictis (ALCOCK 1890)

Fig. 417

Investigated otoliths: 1 otolith (right side) from

the Madras coast, India, BMNH 1927.1.6.30-32.

Figs. 415-416: Psettina iijimae (JORDAN & STARKS 1904) – 15 ×

416b

416a

415

416c

186

Schwarzhans: Pleuronectiformes

Discussion: Otoliths of P. iijimae are considera-

bly more compressed.

Distribution: SE-India and Indonesia.

Psettina iijimae (JORDAN & STARKS 1904)

Figs. 415-416

Investigated otoliths: 2 otoliths (right and left

side) from Okishima, Japan, ZMH Ot. 25.5.1994.1

(leg. BMNH 1931.8.19.4) and BMNH 1931.8.19.4.

Discussion: More compressed than P. brevirictis.

Distribution: Southern Japan.

Taeniopsetta GILBERT 1905

Type-species: Taeniopsetta radula GILBERT 1905

Diagnosis: Moderately thick and rather large

otoliths with a more or less rectangular outline;

ventral rim shallow, postventrally pronounced,

dorsal rim flat, horizontal, with marked pre-and

postdorsal angles, posterior tip blunt, oblique, its

tip shifted ventrally, anterior rim blunt, rarely with

incipient short rostrum, but without excisura;

index l:h 1.3-1.4. Otolith size up to 3.5-4 mm.

Ostium longer than cauda and very slightly

wider. Sulcus very narrow, moderately deep,

slightly inclined, with somewhat reduced ostial

opening. Cauda terminating at moderate distance

from posterior tip of otolith. Colliculi well sepa-

rated. Dorsal and ventral depressions moderate-

ly deep, wide and well marked, connected around

caudal tip to form a circumsulcal depression.

Inner face rather flat and rather smooth; out-

er face convex, smooth to slightly ornamented.

Rims moderately sharp, usually somewhat un-

dulating.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

ocellata 1.30-1.40 2.5 1.5-1.6 1.1-1.2 5° 4

radula 1.40 2.2 1.45 1.25 0° 4.5

†dorsolobata 1.30-1.45 nm 1.0-1.1 1.3-1.4 0° nm

Side dimorphism: Not apparent.

Variability: Variability of otoliths in this genus

is very much restricted to details of the expres-

sion of the dorsal rim.

Discussion: NORMAN (1934) placed Taeniopsetta

in his Paralichthyinae, in a systematic position

quite distant to the genera here included in the

Arnoglossus-Group. Its otoliths, however, show

considerable resemblance to those of the other

genera in this group, particularly as far as outline

and inclination of the sulcus is concerned. I have

therefore tentatively included Taeniopsetta in the

Arnoglossus-Group.

Species and distribution: Two recent species

with rather restricted distribution patterns –

T. ocellata from the Indian Ocean and T. radula

from Hawaii. In addition I have tentatively placed

in this genus the fossil T. dorsolobata from the

Lower Miocene of New Zealand.

Taeniopsetta ocellata (GÜNTHER 1880)

Figs. 418-421

Investigated otoliths: 4 otoliths (3 right side and

1 left side) from Saya de Molha Bank, Indian

Ocean, ZMH Ot. 25.5.1994.6-8 (leg. BMNH

1908.3.23.123-5) and BMNH 1908.3.23.123-5.

Variability: The expression of the predorsal an-

gle seems to be the only character of a certain

variance.

Discussion: See entry to T. dorsolobata and to

T. radula.

Distribution: NORMAN (1934) reported this

species from two very distant locations. One lo-

cation is the Admirality Islands near New Guin-

ea (holotype), the other the Saya de Molha Bank

north of Mauritius in the Indian Ocean (investi-

gated specimens).

Fig. 417: Psettina brevirictis (ALCOCK 1890) – 15 ×

187

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Taeniopsetta radula GILBERT 1905

Fig. 422

Investigated otoliths: 1 otolith (right side), para-

type, from Hawaii, BMNH 1931.8.19.1-2.

Discussion: The otolith of T. radula is slightly

more thickset than those of T. ocellata, its sulcus

somewhat wider and the postdorsal angle is more

strongly developed than the predorsal angle.

Distribution: Restricted to the Hawaiian Islands.

Taeniopsetta dorsolobata

(SCHWARZHANS 1980)

Figs. 423-426

syn. Bothidarum dorsolobatus SCHWARZHANS

1980 – SCHWARZHANS 1980: fig. 582-584

Investigated otoliths: 4 otoliths, the holotype

(fig. 423) and the two paratypes (figs. 424-425)

from Pukeuri, Otago, New Zealand South Island,

Altonian, Lower Miocene, NZGS, and 1 otolith

(fig. 426) from Awamoa Creek, Otago, New Zea-

land South Island, Altonian, Lower Miocene, coll.

Richardson.

Ontogeny and variability: The smallest speci-

men (fig. 425) is more elongate than the larger

ones. One specimen (fig. 424) shows a slightly

stronger rostrum.

Discussion: T. dorsolobata is placed provisional-

ly in this genus. It differs from the two recent

species in a number of aspects. These are the in-

dex ol:cl, the somewhat wider sulcus, the incip-

ient rostrum, the strongly pronounced medio- to

postdorsal angle (in T. ocellata it is the predorsal

angle, in T. radula it is the postdorsal angle) and

the rather flat inner face. However, there is no

other recent genus, which would show similar

features, but it may eventually turn out that T. dor-

solobata represents an extinct genus altogether.

Figs. 418-421: Taeniopsetta ocellata (GÜNTHER 1880) – 10 ×

Fig. 422: Taeniopsetta radula GILBERT 1905 – 15 ×

418b

418a

419

418c

420

421

422b

422a

422c

188

Schwarzhans: Pleuronectiformes

Distribution: Lower Miocene of the southeast-

ern part of the South Island of New Zealand.

7.6.7 Monolene-Laeops Group

Genera: In this group I have tentatively placed 6

genera – Trichopsetta, Engyophrys, Perissias, Lae-

ops, Japanolaeops and Monolene. The first three

genera are confined to the tropical coasts of

America, Monolene occurs along the coasts of

America and West Africa, and Laeops and Japa-

nolaeops are distributed in the Indo-Pacific. Oto-

liths are unknown from Perissias and Japanolaeops.

Perissias is placed here, because of NORMAN’s

correlation with Trichopsetta and Engyophrys, Japa-

nolaeops because of its apparent relationship to

Laeops. There are also few fossil records – one

possible species of Monolene from the Upper Oli-

gocene of the North Sea Basin and two species of

Laeops, one from the Middle Miocene of the Para-

tethys and one from the Lower Pliocene of Mo-

rocco.

Definition and relationship: Otoliths of the

Monolene-Laeops Group closely resemble those of

the Arnoglossus Group. They are compact and

small and compressed in outline. The sulcus

opening is not much reduced. Dorsal and ventral

depressions are well marked and connected

around the caudal tip. The inner face is rather

flat, sometimes almost completely flat. Differing

from the Arnoglossus Group is the more trapezoi-

dal than rectangular outline of the otoliths and in

many (but not all) instances the almost horizon-

tal orientation of the sulcus. The inner face is

usually “more” flat and some genera show a pro-

nounced side dimorphism. However, there exist

a number of intermediate morphologies, which

in several instances does not allow to draw a very

definite boundary between the members of the

two groups.

In NORMAN’s (1934) concept most of the

genera placed in the Monolene-Laeops Group where

not regarded to be particularly related to the gen-

era of the Arnoglossus Group. In fact, he placed all

genera in his Paralichthyinae except for Laeops

(and Japanolaeops, which was described later).

NORMAN used three characters to differentiate

among the two subfamilies Paralichthynae and

Bothinae – placement of the ventral fin in relation

to each other, location of the cleithra in relation to

the most anterior of the ventral fins and presence

or absence of the processus transversus on the

caudal vertebrae. The implications of these three

characters for the distinction of the two genera

Monolene and Laeops has been discussed at length

by NIELSEN (1961) in his description of Mono-

lene mertensi, a species originally described as be-

longing to Laeops. Interestingly, the fishes of these

two genera not only resemble each other in habi-

tus but also there otoliths can hardly be differen-

tiated. It may be possible that the latter is due the

“very reduced” morphology of the otoliths which

leaves few diagnostically valid characters. On the

other hand, such tendencies or otolith patterns

are not observed in any of the other Paralichthy-

nae genera (Paralichthys, Pseudorhombus, Syacium

and Citharichthys Groups). The only exceptions

from this are the two genera Trichopsetta and

Figs. 423-426: Taeniopsetta dorsolobata (SCHWARZHANS 1980) – 25 ×

426b

426a

423

426c

425

424

189

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Engyophrys. – These are the principal reasons, why

I have united the 6 genera listed above in the

Monolene-Laeops Group and placed them in the

vicinity of the Arnoglossus Group, well aware, of

course, that this classification contradicts the ich-

thyological concept of NORMAN. In recent liter-

ature, however, (HENSLEY & AHLSTROM, 1984,

NELSON, 1994) these genera in question are in-

cluded with the Bothidae, very similar indeed to

the otolith grouping as proposed here.

Trichopsetta GILL 1889

Type-species: Citharichthys ventralis GOODE &

BEAN 1886

Diagnosis: Relatively thick, small otoliths with

a more or less trapezoidal outline; ventral rim

shallow, almost straight, dorsal rim flat, with

marked pre-and postdorsal angles, posterior tip

blunt, slightly oblique and ventrally pronounced,

anterior rim oblique, with incipient short rostrum,

but without excisura; index l:h 1.45-1.55. Otolith

size about 3 mm.

Ostium longer than cauda and slightly wider

too. Sulcus moderately deep, slightly inclined,

with a somewhat reduced ostial opening. Cauda

terminating at moderate distance from posterior

tip of otolith. Colliculi well separated. Dorsal and

ventral depressions wide, well marked towards

the sulcus, more or less connected around caudal

tip to form a circumsulcal depression.

Inner face almost flat except for the some-

what elevated area around the sulcus, rather

smooth; outer face convex, smooth. Rims moder-

ately sharp, smooth.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.o

ventralis (right) 1.45 2.3 1.2 1.0 10° 2.7

ventralis (left) 1.55 nm 2.2 1.3 0° nm

melasma (right) 1.60 2.9 1.3 1.0 10° 5

Side dimorphism: Trichopsetta belongs to the

genera within this group with a rather pro-

nounced side dimorphism. This is most obvious

in the outline of the otolith – the right hand oto-

lith shows the typical trapezoidal outline, where-

as the left hand otolith is much more rounded.

Also the right hand otolith shows an inclined

sulcus, the left hand otolith a nearly horizontal

orientation. Separation of colliculi is much less

developed in the left hand otolith, the sulcus more

narrow and the index ol:cl is much larger.

Discussion: Trichopsetta apparently is closely re-

lated to Engyophrys. With otoliths of more species

of the two genera becoming available I would

expect differentiation of the two genera to be-

come very difficult, if at all possible. In fact, the

separation of the two genera appears to be some-

what artificial judging from otoliths alone.

Species and distribution: Trichopsetta includes 4

recent species – T. caribbaea, T. melasma, T. orbiscu-

lus and T. ventralis – all endemic to the deeper

water of the Gulf of Mexico and the Caribbean.

Trichopsetta ventralis

(GOODE & BEAN 1886)

Figs. 427-428, 16

Investigated otoliths: 2 otoliths (right and left

side) from off Florida (29°14’N/88°09’W), BMNH

96.2.10.74.

Discussion: Otoliths of T. ventralis are more com-

pressed than those of T. melasma.

Distribution: In deeper water throughout the

Gulf of Mexico.

Trichopsetta melasma ANDERSON &

GUTHERZ 1967

Fig. 429

Investigated otoliths: 1 otolith (right side), para-

type, Andros Isl., 24°34’N/79°6’W, BMNH

1966.6.13.3.

Discussion: More elongate than T. ventralis and

with pointed posterior tip. In appearance T. melas-

ma is very similar to Engyophrys sanctilaurenti (see

respective entry). The separation of the two gen-

era, at least by means of otoliths, seems rather

artificial

Engyophrys JORDAN & BOLLMAN 1890

Type-species: Engyophrys sanctilaurenti JOR-

DAN & BOLLMAN 1890

Diagnosis: Relatively thick, small otoliths with

a rounded trapezoidal outline; ventral rim shal-

low, almost straight, dorsal rim flat, with round-

ed pre-and postdorsal angles, posterior tip ven-

190

Schwarzhans: Pleuronectiformes

trally pointed in right hand otoliths, rounded in

left hand otoliths, anterior rim blunt, without

rostrum; index l:h about 1.55. Otolith size about

3 mm.

Ostium longer than cauda and slightly wider

too. Sulcus moderately deep, horizontal, with a

somewhat reduced ostial opening. Cauda termi-

nating at some distance from posterior tip of oto-

lith. Colliculi indistinctly separated. Dorsal and

ventral depressions wide, not well marked, more

or less connected around caudal tip to form a

circumsulcal depression.

Inner face almost flat, rather smooth; outer

face convex, smooth. Rims moderately sharp,

smooth.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.o

sanctilaurenti 1.55 2.4 1.6-1.7 1.3 0° 3

Side dimorphism: Side dimorphism in Engyo-

phrys is somewhat less developed than in Tri-

chopsetta. The right hand otolith shows a pointed

posterior tip, the left hand otolith a rounded

posterior tip. Also the sulcus is narrower and

deeper in left hand otoliths.

Discussion: Engyophrys apparently is loosely

related to Trichopsetta. Main difference is the de-

velopment of the posterior tip of the otolith and

the lack of a sulcus inclination.

Species and distribution: Three species, one

from the Pacific coast of Panama and Columbia –

E. sanctilaurenti – and one from the Atlantic coast

off Florida – E. sentus (acc. to NORMAN only

known from the single holotype) – and one from

Brazil – E. ciliaris.

Engyophrys sanctilaurenti

JORDAN & BOLLMAN 1890

Figs. 430-431

Investigated otoliths: 2 otoliths (right and left

side) from the Pacific coast of Mexico, off Mazat-

lan (23°6’N/107°9’W), ZMH Ot. 26.5.1994.1-2 (leg.

ZMUC ex SIO 59-262-64A).

Discussion and distribution: See entry to genus.

Figs. 427-428: Trichopsetta ventralis (GOODE & BEAN 1886) – 15 ×

Fig. 429: Trichopsetta melasma ANDERSON & GUTHERZ 1967 – 15 ×

427b

427a

428 427

429b

429a

191

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Perissias JORDAN & EVERMANN 1898

Type-species: Platophrys taeniopterus GILBERT

1890

Remarks: A specimen of P. taeniopterus in the

ZMUC collection was x-rayed and revealed that

otoliths have been dissolved (by formalin). Ac-

cording to NORMAN (1934) Perissias is closely

related to Trichopsetta and Engyophrys.

Species and distribution: Perissias is a monospe-

cific genus with P. taeniopterus known from the

Pacific coast of California to Panama.

Laeops GÜNTHER 1880

Type-species: Laeops parviceps GÜNTHER 1880

syn. Scianectes ALCOCK 1889 (type-species:

Scianectes macrophthalmus)

syn. Lambdopsetta SMITH & POPE 1906 (type-

species: Lambdopsetta kitaharae)

syn. Laeoptichthys HUBBS 1915 (type-species:

Laeoptichthys fragilis, ?syn. L. kitaharae)

syn. Leptolaeops FOWLER 1934 (type-species: Lep-

tolaeops clarus)

Diagnosis: Relatively thick, small and com-

pressed otoliths with a more or less trapezoidal

outline; ventral rim shallow, almost straight, dor-

sal rim flat, with marked pre-and postdorsal an-

gles, posterior tip blunt, slightly oblique and

ventrally pronounced, anterior rim oblique, with

incipient short rostrum, but without excisura;

index l:h 1.10-1.40. Otolith size up to 3 mm.

Ostium longer than cauda and usually wider.

Sulcus moderately deep, sometimes inclined, with

a somewhat reduced ostial opening. Cauda ter-

minating at moderate distance from posterior tip

of otolith. Colliculi well separated. Dorsal and

ventral depressions wide, well marked towards

the sulcus, connected around caudal tip to form

a circumsulcal depression.

Inner face almost flat except for the some-

what elevated area around the sulcus, rather

smooth; outer face convex, smooth. Rims moder-

ately sharp to thickset, smooth.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.o

guentheri 1.35-1.40 2.6 1.6-1.8 1.6 0° 3.5

nigrescens 1.20-1.30 2.8 1.3-1.5 1.2-1.3 5-10° 2.5

macrophthalmus 1.15-1.20 2.8 1.1-1.4 1.5 5-10° 2.7

nigromaculatus 1.10 nm 2.0 1.1 0° nm

†splendens 1.20 3.0 1.3-1.4 1.2 10-15° 3.0

†rharbensis 1.00-1.10 3.0-3.3 1.9-2.2 1.6-1.7 10° 3.0

Side dimorphism: Generally not apparent. In the

fossil L. splendens the right hand otolith is more

rounded in outline and lacks a rostrum. Howev-

er, since this is an extremely small otolith these

apparent differences could at least partially be

due to allometric ontogenetic growth.

Ontogeny and variability: Except for the possi-

ble case in the fossil L. splendens no remarkable

ontogenetic changes have been observed. Oto-

liths of about 1.5 mm usually have developed all

pertinent diagnostic features. Variability too in

most species seems to be moderate, mainly re-

stricted to details of the outline.

Discussion: Otoliths of Laeops are extremely sim-

ilar to those of the genus Monolene, which in ich-

thyological literature are not regarded as partic-

Figs. 430-431: Engyophrys sanctilaurenti JORDAN & BOLLMAN 1890 – 15 ×

430b

430a

431

430c

192

Schwarzhans: Pleuronectiformes

ularly related (see NORMAN 1934 and general

remarks to the Monolene-Laeops Group). In fact I

can not find a single otolith character that would

allow a safe distinction of the two. Both genera

are quite specious and so far only a limited

number of species are known from otoliths. Once

our knowledge increases I would expect even

more uncertainty in telling the species of the two

genera apart by means of otoliths. This implies,

of course, that the allocation of fossil otoliths to

the one or other genus probably will always re-

main somewhat questionable (see entries to the

fossil species). In rare instances even the distinc-

tion to certain species of the genus Arnoglossus

may become problematical. The single most reli-

able character to distinguish otoliths of Monolene

and Laeops from those genera of the Arnoglossus

Group probably is the trapezoidal outline of the

former.

Species and distribution: There are about 15

nominally valid species in the genus Laeops:

L. clarus, L. cypho and L. gracilis (all described by

FOWLER, 1933 from the Philippines), L. guen-

theri, L. kitaharae, L. lanceolata, L. variegata (the two

latter likely synonyms of L. kitaharae), L. macroph-

thalmus, L. natalensis, L. nigrescens, L. nigromacula-

tus, L. parviceps, L. pectoralis, L. sinusarabici,

L. tungkongensis. Judging from the comments and

listings of NORMAN (1934) and CHABANAUD

(1939) the genus is in need of revision and may

be less than 10 species may finally prove to be

valid. Otoliths of four recent species are figured

here. Otoliths of a fifth species – L. pectoralis – are

figured in SMALE et al. (1995). They resemble

those of L. guentheri with the predorsal lobe.

Laeops is widely distributed in the Indo-West-

Pacific, from South Africa to Japan and the Phil-

ippines. In addition there are two fossil records

tentatively placed in this genus (regarding Mon-

olene as an alternative allocation) – L. splendens

from the Middle Miocene of the Paratethys (Aus-

tria) and L. rharbensis from the Lower Pliocene of

NW-Morocco.

Laeops guentheri ALCOCK 1890

Figs. 432-433

Investigated otoliths: 3 otoliths (2 right side and

1 left side) from off Calcutta, India, ZMH Ot.

26.5.1994.3-4 (leg. BMNH 1928.3.29.3-4) and

BMNH 1928.3.29.3-4.

Discussion: The otoliths of L. guentheri are char-

acterized by their rather elongate shape, the lack

of a sulcal inclination and a conspicuous middor-

sal concavity.

Distribution: Persian Gulf and along the coasts

of Pakistan and India to Burma.

Laeops nigrescens LLOYD 1907

Figs. 434-437

Investigated otoliths: 14 otoliths (9 right side and

5 left side) from the Gulf of Aden, ZMH Ot.

26.5.1994.5-12 (leg. BMNH 1939.5.24.1739-73) and

BMNH 1939.5.24.1739-73.

Ontogeny and variability: Both ontogenetic

changes and variability in this species is relative-

ly small and restricted to minor variations in the

outline of the otolith.

Discussion: Otoliths of L. nigrescens are compact,

compressed and show the typical trapezoidal

outline. They are very similar to L. macrophthal-

mus.

Distribution: Gulf of Aden, in relatively deep

water.

Figs. 432-433: Laeops guentheri ALCOCK 1890 – 15 ×

432b 432a

433

432c

193

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Laeops macrophthalmus (ALCOCK 1889)

Figs. 438-439

syn. Scianectes lophoptera ALCOCK 1889

Investigated otoliths: 5 otoliths, 2 otoliths (right

and left side, fig. 438-439) from the bay of Bengal,

BMNH 1927.1.6.59-60, 3 otoliths (2 right side, 1

left side) from the Sea of Oman, ZMH Ot.

26.5.1994.13-15 (leg. BMNH 1904.5.25.2-5).

Discussion: L. macrophthalmus is very similar to

L. nigrescens. However, the otoliths seem to be

just slightly more compressed and the predorsal

angle more pronounced.

Distribution: From the Gulf of Oman through

the Indian Ocean to Burma.

Laeops nigromaculatus VON BONDE 1922

Fig. 440

Investigated otoliths: 1 slightly eroded otolith

(right side), paratype, off Natal, South Africa,

BMNH 1922.3.27.13-14.

Discussion: A very compressed, roundish oto-

lith with an anisole narrow sulcus, including a

very narrow ostium.

Figs. 434-437: Laeops nigrescens LLOYD 1907 – 15 ×

Figs. 438-439: Laeops macrophthalmus (ALCOCK 1889) – 15 ×

Fig. 440: Laeops nigromaculatus VON BONDE 1922 – 15 ×

434b

434a

435

434c

438b

438a

436

438c

437

439

440

194

Schwarzhans: Pleuronectiformes

Distribution: Off Natal coast and Delagoa Bay,

South Africa.

Laeops splendens (SCHUBERT 1906)

Figs. 441-443

syn. Ot. Pleuronectidarum splendens SCHUBERT

1906 – SCHUBERT 1906: pl. 6, fig. 10-11

syn. Solea tenuis SCHUBERT 1906 – SCHUBERT

1906: pl. 6, fig. 9

syn. Hippoglossoides splendens – NOLF 1981: pl. 3,

fig. 11

syn. genus Pleuronectiformorum tenuis – NOLF

1981: no fig.

Investigated otoliths: 3 otoliths, the lectotype

(GBW 1906/1/57a; fig. 441) and paralectotype

(GBW 1906/1/57b; fig. 442) of Ot. Pleuronecti-

darum splendens from the Badenian, Middle Mi-

ocene of Bad Vöslau, Vienna Basin, Austria and

the holotype (GBW 1906/1/56; fig. 443) of Solea

tenuis from the Badenian of Neudorf an der

Merch, Vienna Basin, Slowakia.

Side dimorphism: The two types of Ot. Pleu-

ronectidarum splendens are left hand otoliths,

whereas the holotype of Solea tenuis is a very small

right hand otolith. The latter differs in the more

roundish shape and the complete lack of a ros-

trum. This may indicate some degree of side di-

morphism, but at least part of the morphological

difference may better be explained by allometric

ontogenetic growth. Because of these uncertain-

ties, this specimen was not used for measure-

ments (see entry to genus).

Discussion: The shape of the dorsal and poste-

rior rims and the rather strongly inclined sulcus

distinguish these otoliths from those of the known

recent species. In all other characters it perfectly

fits into this genus.

Distribution: Middle Miocene of the Vienna

Basin (Paratethys).

Laeops rharbensis n.sp.

Figs. 444-447

Name: Referring to the Rharb province of NW-

Morocco, where these otoliths were found.

Holotype: Fig. 444, SMF P 9319.

Type-locality: Right river banks of the Oued Beth,

ca. 1 km south of Dar Bel Hamri, NW-Morocco.

Age: Lumachelle at the base of the Sands of Dar

Bel Hamri, Lower Pliocene.

Paratypes: 6 otoliths (figs. 445-447), topo- and

stratitypic., SMF P 9320.

Diagnosis: Very compressed otoliths with an

index l:h of about 1.0. Outline trapezoidal, some-

what undulating. Inner face rather flat and

smooth, with slightly inclined sulcus. Ostium

much longer and wider than cauda.

Description: Outline: Massive, compressed oto-

liths, about as long as high, with somewhat un-

dulating trapezoidal outline. Ventral rim flat,

dorsal rim almost straight, with pre- and post-

dorsal angles. Anterior and posterior rims ob-

lique, anterior rim with incipient rostrum, poste-

rior rim often with small notch.

Inner face: Relatively flat and smooth, with

inclined and rather short sulcus. Sulcus opening

somewhat reduced. Ostium much longer and

wider than cauda, the latter terminating at mod-

erate distance from the posterior rim of the oto-

Figs. 441-443: Laeops splendens (SCHUBERT 1906) – 15 ×

441b

441a

442

441c

443b

443a

443c

195

Piscium Catalogus, Part Otolithi piscium, Vol. 2

lith. Colliculi well separated, caudal colliculum

very small. Dorsal and ventral depressions wide,

rather shallow, but well marked towards the sul-

cus, connected around the caudal tip.

Other views: Otolith rim rather thickset, smooth.

Outer face convex, smooth.

Ontogeny and Variability: In smaller specimens

the marginal crenulation is more strongly devel-

oped. Also otoliths seem to grow more thickset

with size. Variability is minor, in principal restrict-

ed to details of the outline.

Side dimorphism: Not apparent.

Discussion: L. rharbensis is a typical example of

a species that based on isolated otoliths could

either be placed in the genus Laeops or Monolene.

In Laeops it closely resembles L. nigrescens and

L. macrophthalmus except for the somewhat more

compressed outline and the very tiny cauda. In

Monolene it resembles M. microstoma, Recent from

the West African coast. This rather variable spe-

cies has even more thickset otoliths, a deep sul-

cus and dorsal and ventral depressions and again

a larger cauda. Of course, it is tempting to place

the fossil species from Morocco in Monolene be-

cause a recent species is known from the same

area at large, but the recent species (M. microsto-

ma) somewhat departs from the “typical” otolith

morphology to be found in the genus. In general,

the trapezoidal outline seems to be more com-

mon in Laeops and this is the main reason, why I

have placed L. rharbensis here.

Japanolaeops AMAOKA 1969

Type-species: Japanolaeops dentatus AMAOKA

1969

Remarks: Otoliths of Japanolaeops have not been

available for identification. Specimens kindly

dissected by K. Sasaki were found to had their

otoliths dissolved due to formalin. Japanolaeops

was tentatively included in the Monolene-Laeops

Group because of its apparent affinities to Laeops.

Species and distribution: Japanolaeops is a mon-

ospecific genus with J. dentatus being endemic to

Japan.

Figs. 444-447: Laeops rharbensis n.sp. – 15 ×

445b

445a

446a

446b

444b

444a

444c

447b

447a

446c

196

Schwarzhans: Pleuronectiformes

Monolene GOODE 1881

Type-species: Monolene sessilicauda GOODE 1881

syn. Thyris GOODE 1881 (preoccupied; type-spe-

cies: Thyris pellucidus, syn. M. sessilicauda)

syn. Delothyris GOODE 1884 (substitute for Thy-

ris)

Diagnosis: Moderately thick to thick, small oto-

liths with an irregular roundish to rectangular to

trapezoidal outline; ventral rim usually deeper

than dorsal rim, the latter flat, often with marked

pre-and postdorsal angles, posterior tip blunt,

slightly oblique and dorsally pronounced or ver-

tically cut, anterior rim blunt or rounded, with-

out rostrum; index l:h 1.1-1.6. Otolith size rarely

reaching 3 mm.

Ostium longer than cauda and slightly wider

too. Sulcus moderately deep to deep, sometimes

slightly inclined, with a somewhat reduced ostial

opening. Cauda terminating at moderate distance

from posterior tip of otolith. Colliculi well sepa-

rated. Dorsal and ventral depressions wide, usu-

ally deep, well marked towards the sulcus, con-

nected around caudal tip to form a circumsulcal

depression.

Inner face rather flat except for the somewhat

elevated area around the sulcus, moderately

smooth; outer face convex, smooth. Rims moder-

ately sharp to thickset, smooth.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.o

antillarum 1.15-1.40 2.8 1.4-1.7 1.0-1.3 0-5° 4.5

sessilicauda 1.25 2.3 1.4 1.1 5° 3.5

microstoma 1.10-1.35 1.8 1.5-2.0 1.0-1.2 0-5° 1.5

maculipinna 1.60 nm 1.6 1.2 0° nm

†priscus 1.20-1.30 2.5-3.0 1.2-1.4 1.0-1.3 0° 3.8

Side dimorphism: Side dimorphism in the oto-

liths of this genus is not very obvious and may

not occur in all species. Sometimes the sulcus of

left hand specimens seems to be more deepened

and they can also be more roundish in outline.

Ontogeny and variability: Due to the rather re-

duced morphology of the otoliths, ontogenetic

changes are strong. Even small otoliths of less

than 2 mm in size generally seem to be morpho-

logically mature. Variability on the other hand

often is very considerable, in particular concern-

ing the outline of the otoliths. This character can

be become so variable in some species that spe-

cific identification can be seriously hampered.

Discussion: Otoliths of Monolene very closely

resemble those of Laeops (see respective entry)

and sometimes it is difficult, if at all possible, to

distinguish amongst the two by means of oto-

liths alone.

Species and distribution: According to

NIELSEN (1961) the genus Monolene contains 10

species, 3 from the Pacific coast of America (M. du-

biosa, M. asaedae, M. maculipinna), 5 from the At-

lantic coast of America (M. sessilicauda, M. antil-

larum, M. atrimana, M. danae, M. megalepis) and 2

from West Africa (M. microstoma, M. mertensi). In

addition, I have tentatively placed a fossil record

from the Upper Oligocene of Germany (North

Sea Basin) in this genus (M. priscus).

Monolene antillarum NORMAN 1933

Figs. 448-451

Investigated otoliths: 8 otoliths (6 right side and

2 left side) from off Dry Tortugas, Florida, ZMH

Ot. 26.5.1994.16-21 (leg. BMNH 1933.10.12.137-

143) and BMNH 1933.10.12.137-143.

Variability: The figured specimens exemplify the

rather large degree of variations found in the

otoliths of this species, in particular as far as

outline and proportions of otoliths are concerned.

One of the otoliths (fig. 451) is much more com-

pressed than the others

Discussion: Otoliths of M. antillarum are amongst

the least characteristic ones to be found in this

genus. In general they seem to be more rounded

in outline than those of the other recent species

investigated.

Distribution: Off the coasts of Florida and the

west Indies.

Monolene sessilicauda GOODE 1881

Figs. 452

syn. Thyris pellucidus GOODE 1881

Investigated otoliths: 1 otolith (right side) from

off Newport, Rhode Island, Atlantic coast of the

USA, ZMH Ot. 26.5.1994.22 (leg. ZMUC, ex

USNM).

197

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: The single otolith of M. sessilicauda

differs from those of the apparently related

M. antillarum in the rectangular outline.

Distribution: Off the coast of southern New

England, Atlantic coast of the USA.

Monolene microstoma (CADENAT 1937)

Figs. 454-457

Investigated otoliths: 8 otoliths (4 right side and

4 left side) from the Atlantide Stat. 120 off Rio

Muni, West Africa (02°9’N/09°7’E), ZMH Ot.

26.5.1994.23-26 (leg. BMNH 1962.6.18.13-19) and

BMNH 1962.6.18.13-19.

Ontogeny and variability: The otoliths of this

species too show a large degree of intraspecific

variability. In particularly the outline is quite

variable ranging from almost rounded to round-

ed with distinct pre- and postdorsal angles to

trapezoidal. Sometimes an incipient rostrum is

being developed. Also proportions of the otoliths

are quite variable. Ontogenetic changes sort of

submerge under the high degree of variability.

However, smaller specimens tend to be less thick-

set than the larger specimens.

Discussion: Due to the high degree of intraspe-

cific variability it is very difficult to reliably de-

fine this species by means of otoliths alone. Oto-

liths with a trapezoidal outline bear a lot of re-

semblance with certain species of the genus Laeops. If

found isolated they might well be mistaken as

representatives of that genus. In this respect it is

interesting to not that prior to the revision of

NIELSEN (1961) M. microstoma was indeed re-

garded as a representative of Laeops.

Distribution: Tropical coasts of West Africa.

Figs. 448-451: Monolene antillarum NORMAN 1933 – 15 ×

Fig. 452: Monolene sessilicauda GOODE 1881 – 15 ×

Fig. 453: Monolene maculipinna GARMAN 1899 – 15 ×

449b

452a

451

452b

450

449a

449c

453

448

452c

198

Schwarzhans: Pleuronectiformes

Monolene maculipinna GARMAN 1899

Fig. 453

Investigated otoliths: 2 otoliths (right and left

side) from the Pacific coast of Columbia (07°7’N/

78°7’W), ZMH Ot. 27-28 (leg. SMF).

Discussion: The otoliths of M. maculipinna are

readily recognized by their rectangular outline

and their elongate shape.

Distribution: Off the Pacific coast of Panama and

Columbia in rather deep water.

Monolene priscus SCHWARZHANS 1994

Figs. 458-461

syn. Monolene priscus SCHWARZHANS 1994 –

SCHWARZHANS 1994: fig. 507-511

Investigated otoliths: 5 otoliths, the holotype

(GPIM-M 2908, fig. 460) and 4 paratypes (GPIM-

M 2909-2911 and SMF P 8724, figs. 458, 459, 461)

from wells in the Lower Rhine Valley near Krefeld

and Erkrath, Chattian, Upper Oligocene.

Ontogeny and variability: Ontogenetic changes

and intraspecific variability are relatively small

in this species, confined to details of the outline

and absence or presence of a faint marginal crenu-

lation.

Discussion: Otoliths of M. priscus are rather in-

conspicuous. They differ from the known recent

species of the genus in their rather regularly

rounded outline. The inclusion of the species in

the genus Monolene has a somewhat tentative

character.

Distribution: Upper Oligocene of the Lower

Rhine Valley, North Sea Basin.

7.6.8 Engyprosopon Group

Genera: Four genera – Asterorhombus, Engypro-

sopon, Crossorhombus and Tosarhombus – distribut-

ed in the Indo-Pacific. Otoliths of Tosarhombus are

not known. The genus is included in the group,

because MACHIDA et al. (1984) placed it near

Crossorhombus.

Definition and relationship: Otoliths of the En-

gyprosopon Group closely resemble to those of the

Arnoglossus Group. They are rather small, com-

pact and rounded rectangular in outline. The

sulcus opening is somewhat reduced. Differing

from the Arnoglossus Group is the rather strongly

convex and smooth inner face. In this respect

Figs. 454-457: Monolene microstoma (CADENAT 1937) – 15 ×

454b

456 457

454a454c

455

199

Piscium Catalogus, Part Otolithi piscium, Vol. 2

otoliths of the Engyprosopon Group look morpho-

logically intermediate between those of the Bothus

Group and the Arnoglossus Group. However,

unlike in the Bothus Group the sulcus is rather

shallow and so are the dorsal and ventral depres-

sions.

NORMAN (1934) placed the genera of this

group in the subfamily Bothinae close to Bothus.

In this genera, like in the Bothus Group as well,

the interorbital region is wider in males than in

females. It is possible that this kind of sexual

dimorphism has some impact on otolith morphol-

ogy as well, as was demonstrated in the case of

Syacium ovale (see entry to genus Syacium), but

the few otoliths available do not allow for such

investigations. In any case, NORMAN’s concept

of relating the genera to Bothus is understandable

and to some degree also supported by otolith

morphology. However, as discussed above, the

otolith pattern found in the Engyprosopon Group

shows some peculiarities morphologically inter-

mediate between the Bothus and Arnoglossus

Group and thus in my opinion warrants their

separation in a group of their own.

Asterorhombus TANAKA 1915

Type-species: Platophrys (Arnoglossus) intermedius

BLEEKER 1866

Diagnosis: Small, elongate, moderately thickset

otoliths; ventral rim rather shallow, somewhat

undulating, dorsal rim slightly more rounded,

undulating, without prominent angles, posterior

tip oblique or with slight projection, anterior rim

blunt, rounded, sometimes with incipient, ven-

trally shifted short rostrum, but without excisu-

ra; index l:h 1.55-1.65. Otolith size probably not

much exceeding 2 mm.

Ostium slightly longer than cauda and slightly

wider. Sulcus rather deep, narrow, anteriorly in-

clined, with a somewhat reduced ostial opening.

Cauda terminating at moderate distance from

posterior tip of otolith. Colliculi deep, separated.

Dorsal and ventral depressions narrow, not very

deep, well marked towards the sulcus, more or

less connected around caudal tip to form a cir-

cumsulcal depression.

Inner face strongly convex in both directions,

not smooth; outer face slightly concave, rather

smooth. Rims moderately sharp.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

intermedius 1.55-1.65 2.8 1.1-1.5 1.4-1.6 5-10° 2.4

Side dimorphism: Not apparent.

Discussion: Asterorhombus probably represents

the most plesiomorphic genus in the Engyprosopon

Group. Its otoliths are morphologically interme-

diate between those of the Arnoglossus Group and

the more advanced Engyprosopon Group. With the

former it shares the deep and inclined sulcus,

with the latter the strongly convex inner face and

the very small size. Interestingly, the two species

now placed in this genus had been placed in Arno-

glossus (A. intermedius) and Engyprosopon

(A. fijiensis) by NORMAN (1934).

Species and distribution: Two species – A. inter-

medius, widely distributed throughout the Indian

Ocean, from East Africa and the Red Sea to Aus-

tralia and the Solomon Islands and A. fijiensis,

from the Fiji Islands and northeastern Australia.

Figs. 458-461: Monolene priscus SCHWARZHANS 1994 – 15 ×

460b

459

460a

460c

458

461

200

Schwarzhans: Pleuronectiformes

Asterorhombus intermedius (BLEEKER 1866)

Figs. 462-463

Investigated otoliths: 3 otoliths (two left and one

right), from Lizard Island, Great Barrier Reef,

Queensland, Australia, AMS I.20753-022.

Discussion: An otolith from the second species –

A. fijiensis – also from the Great Barrier Reef off

Queensland (AMS I.22579-018) was found to be

strongly affected by formalin and therefore is not

figured. Anyway, it is very similar to A. interme-

dius, may be just slightly more compressed.

Distribution: Throughout the Indian Ocean from

East Africa and the Red Sea to Australia.

Engyprosopon GÜNTHER 1862

Type-species: Rhombus mogkii BLEEKER 1854

syn. Scaeops JORDAN & STARKS 1904 (type-spe-

cies: Rhombus grandisquama)

Diagnosis: Small, thickset otoliths with a round-

ed, oval outline; ventral rim gently and moder-

ately deep curving, dorsal rim less curving, usu-

ally with a rounded predorsal angle, posterior

tip rounded or oblique, then with its tip shifted

dorsally, anterior rim blunt, rounded, sometimes

with incipient short rostrum, but without excisu-

ra; index l:h 1.2-1.7. Otolith size rarely up to 3 mm.

Ostium considerably longer than cauda and

slightly wider. Sulcus rather shallow, sometimes

slightly inclined, with a somewhat reduced ostial

opening. Cauda terminating at moderate distance

from posterior tip of otolith. Colliculi well sepa-

rated. Dorsal and ventral depressions narrow,

rather shallow, but well marked towards the sul-

cus, more or less connected around caudal tip to

form a circumsulcal depression.

Inner face rather strongly convex and rela-

tively smooth; outer face flat, smooth. Rims mod-

erately sharp, smooth.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

xenandrus (right) 1.35 2.6 1.4 1.1 5° 3.0

xenandrus (left) 1.50-1.70 2.6 1.6-1.8 1.1-1.2 5-10° 3.0

filimanus (right) 1.30 nm 1.6 1.1 5° nm

cocosensis (right) 1.25 2.5 0.8 1.1 20° 3.2

grandisquama (r) 1.20 2.4 1.3 1.0 0-5° 2.0

bleekeri (right) 1.20 3.2 1.5 1.0 0-5° 3.7

Side dimorphism: Left hand otoliths usually are

considerably more elongate than right hand oto-

liths. This is mainly due to the development of an

incipient rostrum and a somewhat more pointed

posterior tip. This is particularly obvious in

E. xenandrus, the only species from which a larg-

er series of otoliths is available. Apart from this,

the index ol:cl is also larger in left hand otoliths.

Variability: Variability is less conspicuous due

to the relatively high degree of side dimorphism.

Discussion: Engyprosopon apparently is related

to Crossorhombus. Generally it seems, that otoliths

of Engyprosopon are somewhat more thickset.

However, only few species have been investigat-

ed and with more knowledge it may become

difficult to reliably differentiate between otoliths

of the two genera.

Figs. 462-463: Asterorhombus intermedius (BLEEKER 1866) – 25 ×

463b

463a

463c

462a

462b

201

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Species and distribution: Engyprosopon is a spe-

cious genus with some 27 species reported and

widely distributed throughout the Indo-Pacific,

from South Africa into the Red Sea, to Hawaii

and the Easter Islands. They are (listing possibly

not complete) – E. arenicola, E. bellonaensis,

E. bleekeri, E. borneensis, E. cocosensis, E. filimanus,

E. grandisquama, E. hawaiiensis, E. hensleyi, E. hu-

reaui, E. latifrons, E. longipelvis, E. longipterum,

E. macrolepis, , E. macroptera, E. maldivensis, E. mog-

kii, E. multisquama, E. natalensis, E. raoulensis, E.

regani, E. rostratum, E. sechellensis, E. septempes,

E.smithi, E. xenandrus, E. xystrias. Several of these

species are known only from the holotype or else

very few specimens. Otoliths are only known from

five species, namely E. xenandrus, E. filimanus,

E. cocosensis, E. bleekeri and E. grandisquama.

Engyprosopon xenandrus GILBERT 1905

Figs. 464-466

Investigated otoliths: 6 otoliths (3 right side and

3 left side) from Hawaii, ZMH Ot. 27.5.1994.1-6

(leg. Fitch).

Discussion: Otoliths of E. xenandrus are more

elongate than those of the other two investigated

species.

Distribution: Hawaiian Islands, in rather deep

water.

Engyprosopon filimanus (REGAN 1908)

Fig. 467

Investigated otoliths: 3 otoliths (right side) from

off Muscat, Sea of Oman, ZMH Ot. 27.5.1994.7-8

(leg. BMNH 1904.5.25.78-80) and BMNH 1904.

5.25.78-80.

Discussion: Otoliths of E. filimanus are rather

compressed with a conspicuous rectangular out-

line.

Distribution: The types of E. filimanus have been

collected from the Maldives Islands. The otoliths

have been extracted from fishes collected in the

Sea of Oman. Their specific identification was

marked with a question mark by NORMAN

(1934).

468b

468a

468c

464a

464b

467

464c

465

466

202

Schwarzhans: Pleuronectiformes

Figs. 464-466: Engyprosopon ×enandrus GILBERT 1905 – 15 ×

Fig. 467: Engyprosopon filimanus (REGAN 1908) – 15 ×

Fig. 468: Engyprosopon cocosensis (BLEEKER 1855) – 15 ×

Engyprosopon cocosensis (BLEEKER 1855)

Fig. 468

Investigated otoliths: 1 otolith (right side) from

the Nicobar Islands, BMNH 1927.1.6.33-37.

Discussion: In its compressed rectangular out-

line this otolith resembles E. filimanus. Very char-

acteristic is the steeply inclined sulcus and the

unusually short ostium (see index ol:cl).

Distribution: Nicobar Islands and coasts of In-

dia and Burma.

Engyprosopon grandisquama

(TEMMINCK & SCHLEGEL 1846)

Fig. 469

syn. Rhombus poecilurus BLEEKER 1852

syn. Rhomboidichthys spilurus GÜNTHER 1880

syn. Scaeops orbicularis JORDAN & SEALE 1907

Investigated otoliths: 2 otoliths (right and left

side) from the Gulf of Manaar, Ceylon, ZMH Ot.9-

10 (leg. ZMH 19950).

Side dimorphism: Side dimorphism in this spe-

cies is much less apparent than in E. xenandrus.

Discussion: Otoliths of E. grandisquama are rela-

tively well rounded in outline, but with a rather

prominent predorsal angle, and very compressed.

Distribution: E. grandisquama is a widely distrib-

uted and apparently rather common species

known from South Africa through the Indian

Ocean to Indonesia, Australia and Japan.

Engyprosopon bleekeri (MACLEAY 1882)

Fig. 470

Investigated otoliths: 1 otolith (right side) from

Nagasaki, Japan, BMNH 1933.6.12.3.

Discussion: Very similar in habitus to E. gran-

disquama, but with a deeper ventral rim and a

shallower dorsal rim with pronounced postdor-

sal angle.

Distribution: NE Australia to southern Japan.

Tosarhombus AMAOKA 1969

Type-species: Tosarhombus octoculatus AMAOKA

1969

Remarks: Otoliths of Tosarhombus have not been

available for investigation. The genus is placed

in the Engyprosopon Group because of its close

allocation with Engyprosopon and Crossorhombus

in MASUDA et al. (1984).

Species and distribution: Tosarhombus is a mon-

ospecific genus with T. octoculatus restricted to

the coasts of Japan.

Fig. 469: Engyprosopon grandisquama (TEMMINCK & SCHLEGEL 1846) – 15 ×

Fig. 470: Engyprosopon bleekeri (MACLEAY 1882) – 15 ×

470a

469a

470b

469b

470c

469c

203

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Crossorhombus REGAN 1920

Type-species: Platophrys dimorphus GILCHRIST

1905 (syn. C. valderostratus)

Diagnosis: Small, thin to moderately thickset

otoliths with a rounded, oval outline; ventral rim

rather shallow, dorsal rim shallow too, variably

with a rounded pre- and/or postdorsal angles,

posterior tip rounded or cut, anterior rim round-

ed, sometimes with incipient short rostrum, but

without excisura; index l:h 1.4-1.5. Otolith size

rarely up to 3 mm.

Ostium considerably longer than cauda and

slightly wider. Sulcus rather shallow to moder-

ately deep, not inclined, with a somewhat reduced

ostial opening. Cauda terminating at moderate

distance from posterior tip of otolith. Colliculi

well separated. Dorsal and ventral depressions

narrow, usually rather shallow, but well marked

towards the sulcus, more or less connected around

caudal tip to form a circumsulcal depression.

Inner face moderately convex and relatively

smooth; outer face flat to slightly convex, smooth.

Rims moderately sharp, smooth.

Measurements:

l:h h:t ol:cl oh:ch s.i.a. con.i

valderostratus 1.35-1.50 2.3 1.5-1.7 1.3-1.4 0° 2.7

azureus 1.50 3.1 1.7 1.4 0-5° 3.8

kanekonis 1.35-1.40 2.6 1.8 1.1 0° 4.3

Side dimorphism: Side dimorphism is moder-

ately developed in C. valderostratus, but absent in

C. kanekonis. When developed, left hand otoliths

are slightly more elongate than right hand oto-

liths, separation of colliculi is less obvious and

the otolith is slightly less thickset.

Ontogeny: The investigated otoliths of C. kane-

konis are somewhat smaller than those of the two

other species (2 mm versus 3 mm) and show some

delicate marginal crenulation. It is quite possible

that this reflects ontogeny.

Discussion: Crossorhombus is closely related to

Engyprosopon (see respective entry for detailed

discussion).

Species and distribution: Crossorhombus contains

four recent species from the Indo-Pacific – C. val-

derostratus, C. azureus, C. kanekonis, C. howensis.

Crossorhombus valderostratus

(ALCOCK 1890)

Figs. 471-472

syn. Platophrys dimorphus GILCHRIST 1905

syn. Scaeops kobensis JORDAN & STARKS 1906

syn. Scaeops ui TANAKA 1918

Investigated otoliths: 2 otoliths (right and left

side) from the Mikawa Bay, Japan, coll. Ohe

#79815-43.

Discussion: Otoliths of C. valderostratus are rather

thickset and show a rounded rectangular outline.

Distribution: C. valderostratus is widely distrib-

uted throughout the Indo-Pacific, from East Afri-

ca to China and Japan.

Crossorhombus azureus (ALCOCK 1889)

Fig. 473

syn. Platophrys microstoma WEBER 1913

Investigated otoliths: 1 otolith (left side) from

off Hongkong, IRSNB (coll. Nolf, leg. Stinton).

Discussion: This relatively thin otolith is char-

acterized by its incipient rostrum.

Distribution: SE-India, Ceylon, Indo-China,

China and Aru Islands.

Crossorhombus kanekonis (TANAKA 1918)

Figs. 474-475

Investigated otoliths: 2 otoliths (right and left

side) from Enshu Nada, Central Japan, coll. Ohe

#78726-32.

Discussion: These small and rather thin otoliths

are characterized by their rather regularly round-

ed outline and the delicate marginal crenulation.

The latter, however, could well represent an on-

togenetic effect.

Distribution: Japan and Taiwan.

204

Schwarzhans: Pleuronectiformes

7.6.9 Thysanopsetta Group

Genera: Thysanopsetta.

Definition and relationship: The small, compact

otoliths of the genus Thysanopsetta are unique in

several aspects. They exhibit a deep excisura and

a relatively strong rostrum and antirostrum. The

sulcus is deeply cut and so are the narrow dorsal

and ventral depressions which are perfectly con-

nected around the caudal tip. The portion around

the sulcus is strongly elevated against the rest of

the inner face. Thus the otoliths do not resemble

any of the other Bothidae. Only a certain overall

resemblance to the Bothus or the Mancopsetta

Groups could be thought of, but this may as well

be purely accidental. As it stands now, Thysanop-

setta is somewhat isolated from the rest of the

Bothidae and its relationship is obscure. I have

therefore selected to place it into an otolith group

of its own.

Apparently NORMAN (1934) felt similar. He

stated that “the relationships of this genus (Thy-

sanopsetta) are somewhat obscure, but it may

Figs. 471-472: Crossorhombus valderostratus (ALCOCK 1890) – 15 ×

Fig. 473: Crossorhombus azureus (ALCOCK 1889) – 15 ×

Figs. 474-475: Crossorhombus kanekonis (TANAKA 1918) – 15 ×

472a

471a

472b

471b

471c

471d

473a

475

473b

472c

474c

473c

474a

474b

205

Piscium Catalogus, Part Otolithi piscium, Vol. 2

conveniently be placed near Tephrinectes”. Oto-

lith morphology, however, strongly contradicts

any relationship with Tephrinectes (see respective

entry).

Thysanopsetta GÜNTHER 1880

Type-species: Thysanopsetta naresi GÜNTHER

1880

Diagnosis: Small, rather thickset and compact

otoliths with a rounded, oval outline; all rims

gently curving, except for the anterior rim, which

shows a deep excisura and marked rostrum and

antirostrum; index l:h about 1.4. Otolith size less

than 3 mm.

Ostium longer than cauda and wider too.

Sulcus very deep, with a clear ostial opening.

Cauda terminating at moderate distance from

posterior tip of otolith. Colliculi separated, deep-

ened. Dorsal and ventral depressions narrow, very

deep and sharp, well connected around caudal

tip to form a circumsulcal depression.

Inner face markedly convex, area around sul-

cus considerably elevated; outer face slightly

convex, smooth. Rims moderately sharp, smooth.

Measurements:

l:h h:t ol:cl oh:ch con.i

naresi 1.40-1.50 2.0 1.8 1.2-1.3 2.0

Side dimorphism: The left hand otolith is slightly

more elongate than the right hand otolith.

Species and distribution: A single species –

T. naresi – from the Magellan-Falkland Islands re-

gion of south-eastern South America.

Thysanopsetta naresi GÜNTHER 1880

Figs. 476-477

Investigated otoliths: 3 otoliths, 2 otoliths (right

and left side) from off Cape Virgins, Argentina,

ZMH Ot. 28.5.1994.1 (leg. BMNH 90.2.26.161) and

BMNH 90.2.26.161, 1 otolith (right side) from off

Punta Arenas, Argentina, ZMH Ot. 28.5.1994.2

(leg. ZMH Ot. 20006).

Discussion and distribution: See entries to ge-

nus and group.

7.6.10 Chascanopsetta Group

Genera: Three genera – Chascanopsetta, Peleca-

nichthys, Kamoharaia – from the deep waters of

the Indo-Pacific. Otoliths are only known from

the genus Chascanopsetta.

Definition and relationship: The fishes of the

three genera placed in this group are readily rec-

ognized by their extremely enlarged mouth. This

character has also been used to separate the two

monospecific genera Pelecanichthys and Kamo-

haraia from Chascanopsetta. CHABANAUD (1939)

has questioned the value of this single character,

which is typical (autapomorphic) for the group

as such, to be used in this sense. He regarded

Pelecanichthys as synonym of Chascanopsetta

(Kamoharaia was not erected then). I find his ar-

gumentation quite convincing, but without addi-

tional otolith material it can not be tested.

Otoliths of Chascanopsetta show an extraordi-

nary strong side dimorphism affecting almost all

possible characters. The left hand otolith differs

from the right hand otolith in the longer sulcus,

the clear ostial opening, the outline of the otolith

(in particular the presence of a massive rostrum),

the presence of a faint excisura (but no antiros-

Figs. 476-477: Thysanopsetta naresi GÜNTHER 1880 – 15 ×

477

476c

476a

476b

206

Schwarzhans: Pleuronectiformes

trum) and the more narrow circumsulcal depres-

sion. Taking the left hand otolith as the more

typical, which reflects an inversion of the usual

type of side dimorphism, the otoliths are further

characterized by their small, compressed size and

the rather flat inner face. They do not particular-

ly resemble any of the other bothid otolith groups

and that is the reason why I have placed these

genera in an otolith group by themselves.

Chascanopsetta ALCOCK 1894

Type-species: Chascanopsetta lugubris ALCOCK

1894

syn. Trachypterophrys FRANZ 1910 (type-species:

T. raptator, syn. C. lugubris)

Diagnosis: Small, moderately thickset otoliths

with aa irregularly rounded outline; ventral rim

shallow, gently curving, dorsal rim much higher,

somewhat irregularly undulating, sometimes

with faint pre- and postdorsal angles, posterior

tip blunt, rounded to slightly pointed inframedi-

anly, anterior tip blunt in right hand otoliths, with

massive rostrum and faint excisura in left hand

otoliths; index l:h 1.25. Otolith size less than 3 mm.

Ostium longer than cauda and slightly wider.

Sulcus moderately deep, with a clear ostial open-

ing in left hand otoliths and somewhat reduced

opening in right hand otoliths. Cauda terminat-

ing at some distance from posterior tip of otolith.

Colliculi separated, deepened. Dorsal and ven-

tral depressions moderately deep, well marked

towards the sulcus and well connected around

caudal tip to form a circumsulcal depression.

Inner face almost flat, area around sulcus

slightly elevated; outer face slightly convex,

smooth. Rims moderately sharp, smooth.

Measurements:

l:h h:t ol:cl oh:ch con.o

lugubris (right) 1.25 3.0 1.6 1.1 3.0

lugubris (left) 1.25 3.0 2.1 1.8 3.0

Side dimorphism: See diagnosis to genus and

discussion to group.

Discussion: See discussion to group.

Species and distribution: There are 8 nominally

valid species in this genus from the deeper wa-

ters of the Indo-Pacific – C. lugubris, C. normani,

C. megagnatha C. microstoma, C. prognathus,

C. prorigera, C. galathaea, C. micrognathus.

Chascanopsetta lugubris ALCOCK 1894

Figs. 478-479, 17

syn. Trachypterophrys raptator FRANZ 1910

syn. Chascanopsetta gilchristi VON BONDE 1922

syn. Chascanopsetta maculata VON BONDE 1922

Investigated otoliths: 2 otoliths (right and left

side) from W off Ceylon, ZMH Ot. 28.5.1994.3

(leg. BMNH 1927.1.6.53) and BMNH 1927.1.6.53.

Side dimorphism: See entry to genus and group.

Distribution: C. lugubris is the most common and

most widely distributed species of the genus, the

other species known from very few specimens or

types only. It is known from SE-Africa through

the Indo-Pacific to Japan.

Pelecanichthys GILBERT & CRAMER 1897

Remarks: Otoliths of Pelecanichthys are not

known. Paratypes kept in the BMNH were found

with completely dissolved otoliths.

Figs. 478-479: Chascanopsetta lugubris ALCOCK 1894 – 15 ×

478

479c

479a

479b

207

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Species and distribution: Pelecanichthys is a mon-

ospecific genus with P. crumenalis restricted to the

deep water around the Hawaiian Islands.

Kamoharaia KURONAMA 1940

Type-species: Chascanopsetta megastoma KAMO-

HARA 1936

Species and distribution: The single species –

K. megastoma – is known from the unique holo-

type from off Japan and a small postlarval taken

in the Philippine Sea (NIELSEN, 1963). Otoliths

have not been available for investigation.

7.6.11 Mancopsetta Group

Genera: Two genera from the Subantarctic and

Antarctic waters – Mancopsetta and Achiropsetta.

Otoliths are only known from Mancopsetta.

Definition and relationship: Otoliths of Manco-

psetta are easily recognized by their high, round-

ed, almost circular outline, the strong rostrum

and the marked excisura. The ostium is only

slightly longer than the cauda. The colliculi are

well separated and deepened. Superficially, Man-

copsetta otoliths somewhat resemble Chascanop-

setta and even Thysanopsetta otoliths, but most of

the characters listed above exemplify their sepa-

rate position. In fact the relationships of these

otoliths to other Bothidae remains obscure.

Likewise, the relationship of these fishes based

on ichthyological analyses has been disputed in

recent literature. EVSEENKO (1984) has proposed

the family Achiropsettidae for these two genera

based on a number of unique characters found in

the fishes. These are the median position of the

vent in front of the anal fin, the position of the tip

of the dorsal fin behind the posterior nostril of

the blind side and the loss of pectoral fins. Al-

though otolith analysis supports the concept of

Mancopsetta and Achiropsetta to be somewhat sep-

arated from the main body of the Bothidae, I do

not feel for the necessity to put them in a separate

family altogether. The general appearance of the

otoliths still is in line with a number of other

aberrant Bothidae (see above).

Mancopsetta GILL 1881

Type-species: Lepidopsetta maculata GÜNTHER

1880

syn. Lepidopsetta GÜNTHER 1880 (preoccupied

by Lepidopsetta GILL 1864, a genus of Pleu-

ronectidae, type-species: L. maculata)

syn. Apterygopectus OJEDA 1978 (type-species:

A. avilesi, syn. M. milfordi)

syn. Neachiropsetta KOTLYAR 1978 (type-spe-

cies: Mancopsetta milfordi)

?syn. Pseudomancopsetta EVSEENKO 1984 (type-

species: P. andriashevi)

Figs. 480-482: Mancopsetta milfordi PENRITH 1965 – 10 ×

480

481c

481a

481b

482

208

Schwarzhans: Pleuronectiformes

Diagnosis: Moderately large and not very thick-

set otoliths with a high, rounded, nearly circular

outline, from which only the massive rostrum

sticks out; all rims gently curving, usually some-

what undulating; the massive rostrum accompa-

nied by a marked excisura; index l:h 1.05-1.35.

Otolith size up to 4 mm.

Ostium slightly longer than cauda, not wider.

Sulcus deep, with a clear ostial opening. Cauda

terminating at some distance from posterior tip

of otolith. Colliculi well separated, strongly deep-

ened. Dorsal and ventral depressions narrow,

often indistinct, but well connected around cau-

dal tip to form a circumsulcal depression.

Inner face flat to slightly convex, rather

smooth; outer face slightly convex, smooth to

slightly undulating. Rims moderately sharp,

smooth to undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

milfordi 1.05-1.10 2.9 1.2-1.5 0.85-1.0 4.5

maculata 1.30-1.35 3.4 1.1-1.3 0.95-1.0 5.0

Side dimorphism: Side dimorphism is moder-

ate in the species of Mancopsetta. In left hand oto-

liths the excisura is usually deeper, the shape may

be slightly more elongate or more regularly

rounded.

Variability: Intraspecific variations are moder-

ate too, mainly restricted to details of the outline.

Discussion: See entry to group.

Species and distribution: There are 2, possibly 3

species from Antarctic and Subantarctic waters –

M. maculata, M. milfordi and M. andriashevi (the

latter when accepting Pseudomancopsetta as a syn-

onym).

Mancopsetta milfordi PENRITH 1965

Figs. 480-482, 18

syn. Apterygopectus avilesi OJEDA 1978

Investigated otoliths: 3 otoliths (2 right side and

1 left side) from off southern New Zealand, ZMH

Ot. 28.5.1994.4-6 (coll. Schwarzhans).

Discussion: Otoliths of M. milfordi are more com-

pressed, higher than those of M. maculata.

Distribution: On the continental shelf and up-

per slope off southern New Zealand and the

southern tip of South America and Islands and

Seamounts in the Subantarctic.

Mancopsetta maculata (GÜNTHER 1880)

Figs. 483-484

syn. Achiropsetta slavae ANDRIASHEV 1960

syn. Mancopsetta antarctica KOTLYAR 1978

Investigated otoliths: 2 otoliths (right and left

side) from off Falkland Islands, ZMH Ot.

28.5.1994.7 (leg. BMNH 1930.5.6.41) and BMNH

1930.5.6.41.

Discussion: Otoliths more elongate than in

M. milfordi.

Distribution: Shelf and slope off southernmost

North America, Islands and Seamounts of the

Subantarctic and coasts of Antarctica. This is the

only flatfish caught at the Antarctic coasts.

484

483c

483a

483b

Figs. 483-484: Mancopsetta maculata (GÜNTHER 1880) – 10 ×

209

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Achiropsetta NORMAN 1930

Type-species: Achiropsetta tricholepis NORMAN

1930

Species and distribution: Achiropsetta apparently

is closely related to Mancopsetta. It is a monospe-

cific genus with A. tricholepis known from the

upper slope off the southernmost tip of South

America, off southern New Zealand and Islands

and Seamounts of the Subantarctic. Otoliths have

not been available for investigation. The type spec-

imen in the BMNH collection apparently repre-

sents a postlarval form. It is nearly translucent

and upon close examination it seemed that oto-

liths were dissolved.

7.7 Pleuronectidae

Genera: The Pleuronectidae contain some 37 re-

cent genera in the limits as presented here. In

alphabetical order they are the following: Acan-

thopsetta, Atherestes, Azygopus, Cleisthenes, Clido-

derma, Dexistes, Embassichthys, Eopsetta, Glyptoce-

phalus, Hippoglossoides, Hippoglossus, Hypsopsetta,

Inopsetta, Isopsetta, Kareius, Lepidopsetta, Limanda,

Liopsetta, Lyopsetta, Marleyella, Microstomus, Nemat-

ops, Parophrys, Pelotretis, Plagiopsetta, Platichthys,

Pleuronectes, Pleuronichthys, Poecilopsetta, Psettich-

thys, Pseudopleuronectes, Reinhardtius, Rhombosolea,

Samaris, Samariscus, Tanakius, Verasper. In addi-

tion, there are three monotypic genera, which

need revision and their generic status verified:

Pluviopsetta TANAKA 1916, Pseudoplatichthys

HIKITA 1934 and Neoetropus HILDEBRAND &

SCHRÖDER 1928.

Definition and relationship: NORMAN (1934)

understood the Pleuronectidae as an assemblage

containing all left eyed Pleuronectoidei, includ-

ing the Brachypleuridae, as well as the genera

which I have placed here in the Paralichthodes and

Ammotretis Groups of uncertain familial relation-

ship. He distinguished 5 subfamilies – Pleuronec-

tinae, containing more than half of the total

number of genera, Poecilopsettinae, Paralichtho-

dinae, Samarinae and Rhombosoleinae – based

on a variety of characters such as symmetry of

pelvic fins, anterior origin of dorsal fin, status of

lateral line on blind side and other characters.

HUBBS (1945) excluded Brachypleura and Lepido-

blepharon from the Samarinae (where they were

placed by NORMAN) and included them in the

Citharidae (in the present study they are thought

to represent a separate family). NORMAN’S

monogeneric Paralichthodinae are here excluded

as well (see Paralithodes Group). Similar views

have also been discussed by HENSLEY & AHL-

STROM (1984) and CHAPLEAU (1993). Based

on otoliths, the Rhombosoleinae sensu NORMAN

are not thought to represent a natural group. The

genera of NORMAN’s Rhombosoleinae are di-

visible into: three groups within the Pleuronecti-

dae (Pelotretis Group, Rhombosolea Group and the

genus Azygopus with the Samaris Group), one

group of uncertain relationship (the Ammotretis

Group with several genera) and one genus (Pelto-

rhamphus) excluded from the Pleuronectoidei and

placed in the Soleidae (Heteromycteris Group, see

respective entry). Only the Pelotretis and Rhombo-

solea Groups may remain in the much reduced

subfamily Rhombosoleinae. The reasoning behind

splitting the Rhombosoleinae is given in detail in

chapter 5.3.2.

NORMAN (1934) roughly subdivided his

Pleuronectinae into two generic groups. One was

to be characterized by a large and symmetrical

mouth (tribe Hippoglossini in NELSON 1994) and

it included genera placed here in the Hippoglossus

and the Hippoglossoides Groups as well as Pset-

tichthys of the Isopsetta Group. The other group

was characterized by a small mouth with asym-

metrical jaws and dentition (tribe Pleuronectini

in NELSON 1994) and it included genera placed

in the Glyptocephalus, Pleuronectes-Limanda,

Isopsetta and Microstomus-Pleuronichthys Groups.

The two genera of the Verasper Group were

thought to be somehow intermediate between the

two groups. Following the analysis of the otolith

morphology I find this bipartition of the Pleu-

ronectinae phylogentically not sound. No doubt

the genera with a large and symmetrical mouth

represent a plesiomorphic condition, but the var-

ious fishes found in NORMAN’s group with a

small and asymmetrical mouth are seemingly the

result of several different lineages of specializa-

tion not necessarily related to each other and

probably derived separately from plesiomorphic

groups (further details will be discussed in the

general entries to the various groups).

Otoliths of the Pleuronectidae exhibit a wide

range of morphological patterns that do not al-

low for a simple definition of the family. With the

Bothidae, the Pleuronectidae share most of the

advanced pleuronectiform otolith patterns such

as the completely developed circumsulcal depres-

210

Schwarzhans: Pleuronectiformes

sion and the rather short cauda. In fact, in com-

parison with the ostium the cauda is often more

strongly reduced in Pleuronectidae than in Both-

idae. Also, most genera constituting the core of

the Pleuronectidae (Pleuronectinae in NORMAN

1934) are characterized by a strong reduction of

the ostial opening. However, well developed os-

tial openings, sometimes even with an excisura,

are also found (Microstomus-Pleuronichthys, Sa-

maris and Poecilopsetta Groups). Except for these

latter groups the sulcus is shallow to very shal-

low and the otoliths are thin with a slightly con-

vex inner face and a concave to flat outer face. In

the three groups already mentioned the sulcus is

deep to extremely deep and the otoliths are ro-

bust. As a result, there is considerable morpho-

logical overlap in the otoliths of the two families

Pleuronectidae and Bothidae and the appropri-

ate placement of otoliths in the one or other fam-

ily will often depend very much on correlation at

generic or group level. Then, however, the taxo-

nomic problem can be solved quite reliably in

most cases. The degree of side dimorphism in

pleuronectid otoliths is often considerably and

affects a large variety of characters. With the

possible exception of Azygopus, there is not a sin-

gle genus in this family without more or less well

developed side dimorphism in the otoliths. Those

of Reinhardtius are amongst the most extreme

examples of side dimorphism found in any oto-

liths.

In this treatise the 37 genera of the Pleuronecti-

dae are organized in 12 informal genus groups

exhibiting similar otolith morphologies. These

genus groups are assigned to 4 informal sub-

families. The groups are: Hippoglossus, Hippoglos-

soides, Glyptocephalus, Pleuronectes-Limanda,

Isopsetta, Verasper, Microstomus-Pleuronichthys,

Samaris, Marleyella, Poecilopsetta, Pelotretis and

Rhombosolea Groups. The first five (Hippoglossus,

Hippoglossoides, Glyptocephalus, Pleuronectes-

Limanda and Isopsetta Groups) represent the core

of NORMAN’s Pleuronectinae and could be de-

scribed as the “typical” forms to be found within

Pleuronectidae. They are all characterized by a

reduced ostial opening, a very small cauda, a

shallow sulcus and thin otoliths with a flat to

slightly concave outer face. Also the Pelotretis and

Rhombosolea Groups (making up the Rhomboso-

leinae) are quite similar except for the ostial open-

ing which is less reduced. The Verasper and Micro-

stomus-Pleuronichthys Groups (also from NOR-

MAN’s Pleuronectinae) stand somewhat apart

from this cluster of groups in possessing a deep

sulcus with a clear ostial opening. In the otoliths

of the Samaris Group (sole group of the Samari-

nae) this trend is taken to its extremes. Here, we

find the deepest sulci within the Pleuronecti-

formes, a deeply cut excisura where the ostium

opens anteriorly and very robust otoliths. Final-

ly, the Marleyella and Poecilopsetta Groups consti-

tute a small cluster of more distantly related gen-

era. Marleyella probably represents the most ple-

siomorphic morphology within this cluster and

the otoliths show a remarkable resemblance to

those of certain citharids. This indicates, that the

two groups either represent a very early diver-

gence from the main branch of the Pleuronecti-

dae or are of pre-pleuronectid origin altogether.

Following the traditional classification they are

here placed under Poecilopsettinae in the Pleu-

ronectidae.

Based on osteological investigations, such as

the hypural patterns, HENSLEY & AHLSTROM

(1984) have questioned the monophyly of Pleu-

ronectidae. Furthermore, they concluded that

Pleuronectinae are more closely related to Both-

idae (s.l., here Paralichthyinae) and that Samari-

nae and Poecilopsettinae might be of different

origin. CHAPLEAU (1993) even proposed rais-

ing Samarinae to family status.

In conclusion, several genus groups or clusters of

pleuronectid genus groups can be well defined

by means of otoliths, as for instance the core of

NORMAN’s Pleuronectinae or his Samarinae

(Samaris Group), whereas others are not so obvi-

ous (Verasper, Microstomus-Pleuronichthys and

Marleyella Groups). Also, there is no single char-

acter found in otoliths to define Pleuronectidae

as a whole and therefore assignment of a certain

otolith to this family has to rely on careful corre-

lation at generic or group level. Even after the

exclusion of Paralichthodes and several genera of

the former Rhombosoleinae from the Pleuronecti-

dae the family is probably still polyphyletic (see

above). Samarinae and Poecilopsettinae are like-

ly further candidates for exclusion. The remain-

der, the Pleuronectinae (auctt.), indeed could be

allocated more closely to the Paralichthyinae in

the sense of HENSLEY & AHLSTROM (1984).

Distribution: Except for the tropical Samaris,

Marleyella and Poecilopsetta Groups the Pleu-

ronectidae show a distinct antitropical distribu-

tion pattern. The pleuronectine groups are restrict-

211

Piscium Catalogus, Part Otolithi piscium, Vol. 2

ed to the temperate and subtropical waters of the

North Atlantic and North Pacific and the Pelotretis

and Rhombosolea Groups (Rhombosoleinae) are

endemic to the temperate seas of New Zealand

and southern Australia. Fishes of the Poecilopsetta

Group occur in deeper water.

Pleuronectinae

7.7.1 Hippoglossus Group

Genera: This group contains the two genera

Eopsetta and Hippoglossus.

Definition and relationship: Within the cluster

of groups representing the core of the Pleuronec-

tinae (NORMAN, 1934) otoliths of this group

probably represent the most plesiomorphic char-

acter status. This is mainly evident from a not yet

so strongly reduced ostial opening and the lack

of specialized sulcus development as observed

in the following groups (see respective entries).

The cauda is short and small, the otoliths thin,

with a slightly convex inner face and a slightly

concave outer face. Otoliths are rather elongate

in shape. The sulcus is relatively long, reaching

close to the posterior tip of the otolith, thus leav-

ing little space for the connection of the circum-

sulcal depression around the tip of the cauda.

The degree of side dimorphism is moderate. It

concerns details of outline and ornamentation of

the otolith and loss of clear separation of the

colliculi in otoliths of the eyed side. As do the

fishes of this group (Hippoglossus is the largest

Pleuronectiform) otoliths grow fairly big reach-

ing up to 15 m.

The Hippoglossus Group falls in NORMAN’s

category of Pleuronectinae with a large and sym-

metrical mouth. The Hippoglossoides Group seems

to be closely related to the Hippoglossus Group

and probably has developed from it. Otoliths of

the Hippoglossoides Group differ in the somewhat

shortened sulcus, the flat inner face and the indi-

vidually deepened colliculi. Also, the Pleuronectes-

Limanda Group may have evolved from near the

Hippoglossus Group and merely differs in the

somewhat more reduced ostial opening and the

shorter sulcus.

Eopsetta JORDAN & GOSS 1887

Type-species: Hippoglossoides jordani LOCKING-

TON 1880

syn. Xystrias JORDAN & STARKS 1904 (type-

species: Hippoglossus grigorjewi)

Diagnosis: Thin, elongate otoliths; ventral rim

shallow, gently curving, deepest behind the mid-

dle, dorsal rim with postdorsal angle, somewhat

undulating, posterior tip blunt to irregularly

rounded, anterior tip strongly projecting like a

rostrum, rounded. Index l:h 1.6 to 1.8. Otolith

size at least 7 mm.

Ostium slightly wider than cauda and much

longer. Index ol:cl 1.7 to 2.0. Ostial opening pseu-

doostial. Cauda short, with rounded termination

at some distance from the posterior rim of the

otolith. Sulcus relatively shallow. Circumsulcal

depression completely connected but rather shal-

low.

Inner face flat in the horizontal direction and

slightly convex in the vertical direction; outer face

slightly concave and rather smooth. Rims sharp,

ventrally smooth, dorsally somewhat undulating.

Measurements:

l:h h:t ol:cl oh:ch con.i

jordani 1.60-1.80 3.5 1.70-2.00 1.1-1.2 about 10

Side dimorphism: Otoliths of the eyed side show

smoother dorsal and posterior rims but a much

more strongly developed postdorsal angle. Os-

tium and cauda are less clearly differentiated,

almost completely fused, and the sulcus as such

is deeper. The circumsulcal depression is less

clearly developed, particularly so its ventral por-

tion.

Discussion: Otoliths of the genus Eopsetta differ

from those of Hippoglossus in the shorter sulcus

and some details of the outline. They also closely

resemble certain genera of the Pleuronectes-Liman-

da Group, thus indicating a close relationship.

Species and distribution: Two species – E. jordani

from the Pacific coast of North America and

E. grigorjewi from Japan, Korea and Taiwan.

212

Schwarzhans: Pleuronectiformes

Eopsetta jordani (LOCKINGTON 1880)

Figs. 485-488

Investigated otoliths: 4 otoliths (left and right)

from off Acapulco, Mexico, Pacific coast, ZMH

Ot. 21.1.1995.1-4 (leg. Fitch).

Distribution: Pacific coast of North America,

USA and northern Mexico, also recorded as fossil

from the Pleistocene of California.

Hippoglossus CUVIER 1817

Type-species: Pleuronectes hippoglossus LINNAE-

US 1758

Diagnosis: Thin, elongate otoliths; ventral rim

very shallow, gently curving, deepest behind the

middle, dorsal rim with postdorsal and predor-

sal angles, posterior tip blunt, anterior tip mod-

erately projecting like a rostrum, blunt, rounded.

Index l:h 1.6 to 1.7. Otolith size at least 15 mm.

Ostium wider than cauda and much longer.

Index ol:cl 1.8 to 2.0. Ostial opening pseudoost-

ial. Cauda short, with rounded termination not

very far from the posterior rim of the otolith.

Sulcus relatively shallow. Circumsulcal depres-

sion not completely connected behind caudal tip

and rather shallow.

Inner face flat in the horizontal direction and

slightly convex in the vertical direction; outer face

slightly concave and with fine radial furrows.

Rims sharp, moderately to intensely crenulated.

Measurements:

l:h h:t ol:cl oh:ch con.i

hippoglossus 1.60-1.65 5.4 1.80 1.2-1.4 about 10

stenolepis 1.70-1.80 4.0 1.85 1.0-1.2 about 10

Side dimorphism: Side dimorphism is moder-

ately developed. Otoliths of the eyed side show

slightly smoother rims, ostium and cauda are less

clearly differentiated, almost completely fused,

and the sulcus as such is deeper. The circumsul-

cal depression is less clearly developed, particu-

larly so its ventral portion.

Discussion: Otoliths of the genus Hippoglossus

are easily recognized by their long sulcus, which

reaches rather closely to the posterior tip of the

otolith.

Species and distribution: Two species – H. hip-

poglossus from the North Atlantic and H. stenolepis

from the North Pacific. Fishes of the genus Hip-

poglossus are active predators often caught in mid-

water.

Hippoglossus hippoglossus (LINNAEUS 1758)

Figs. 489-490

syn. Hippoglossus vulgaris FLEMING 1828

syn. Hippoglossus septentrionalis THON 1831

syn. Hippoglossus maximus GOTTSCHE 1835

syn. Hippoglossus gigas SWAINSON 1839

syn. Hippoglossus ponticus BONAPARTE 1846

syn. Hippoglossus americanus GILL 1864

syn. Hippoglossus linnei MALM 1877

Figs. 485-488: Eopsetta jordani (LOCKINGTON 1880) – 6 ×

486

485c

485a

485b

488

487

213

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Investigated otoliths: 2 otoliths (left and right)

from the North Atlantic, Meteor St. 814, ZMH Ot.

21.1.1995.5-6 (leg. W. Schmidt).

Discussion: H. hipoglossus differs from H. sten-

olepis in the more massive predorsal angle and

the shorter and blunter rostrum.

Distribution: North Atlantic as far north as Spitz-

bergen and Greenland.

Hippoglossus stenolepis SCHMIDT 1904

Figs. 491-492

Investigated otoliths: 2 otoliths (left and right)

from the Bering Sea, ZMH Ot. 21.1.1995.7-8 (leg.

Fitch).

Discussion: See entry to H. hippoglossus.

Distribution: North Pacific, Bering Sea, Okhotsk

Sea, and Alaska to California (there also as fossil

from the Pleistocene).

7.7.2 Hippoglossoides Group

Genera: 6 genera are placed in this group – Ather-

estes, Cleisthenes, Lyopsetta, Acanthopsetta, Hippo-

glossoides and Reinhardtius from the North Atlan-

tic and the North Pacific.

Definition and relationship: The otoliths of the

genera combined in the Hippoglossoides Group are

relatively easily recognized by their extremely flat

and smooth inner face, the rather short sulcus

with its individually deepened and well separat-

Figs. 489-490: Hippoglossus hippoglossus (LINNAEUS 1758) – 4 ×

Figs. 491-492: Hippoglossus stenolepis SCHMIDT 1904 – 4 ×

490a

489a

489b

490b

492a

491a

491b

492b

214

Schwarzhans: Pleuronectiformes

ed colliculi and the very wide and well devel-

oped circumsulcal depression. Side dimorphism

is developed variably, from feeble as in Atherestes

to one of the most prominent expressions as in

Reinhardtius (see entries to genera).

The Hippoglossoides Group represents a mor-

phologically well defined and dense cluster of

genera probably having descended from near the

Hippoglossus Group. Like this group, the Hip-

poglossoides Group belongs to NORMAN’s cate-

gory of Pleuronectinae with a large and symmet-

rical mouth. Also closely related probably is the

Glyptocephalus Group, which differs merely in

showing more compressed otolith shapes.

Atherestes JORDAN & GILBERT 1881

Type-species: Platisomatichthys stomias JORDAN

& GILBERT 1881

Diagnosis: Thin, moderately elongate otoliths;

ventral rim shallow, gently curving, deepest at

about the middle, dorsal rim with postdorsal and

somewhat more prominent predorsal angle,

sometimes finely crenulated, posterior tip blunt

to irregularly rounded, anterior tip projecting like

a rostrum, rounded. Index l:h 1.5 to 1.9. Otolith

size at least 9 mm. Otoliths below a size of 6.5 mm

may not have developed all pertinent diagnostic

features.

Ostium wider than cauda and much longer.

Index ol:cl 1.6 to 2.2. Ostial opening strongly re-

duced. Cauda short, with rounded termination

at considerable distance from the posterior rim of

the otolith. Sulcus well divided into ostium and

cauda, its respective colliculi deepened (only in

otoliths of the blind, left side). Circumsulcal de-

pression completely connected, wide and rather

deep.

Inner face almost completely flat and rather

smooth; outer face also practically flat, with little

ornamentation. Rims sharp, ventrally smooth,

dorsally and posteriorly sometimes finely crenu-

lated.

Measurements:

l:h h:t ol:cl oh:ch con.i

stomias (left) 1.60-1.90 4.5 1.60-2.00 1.3-1.4 nm

stomias (right) 1.50-1.60 nm 1.75-2.25 1.1-1.2 nm

evermanni (left) 1.50-1.65 4.5 2.2 1.2-1.5 nm

evermanni (right) 1.50 nm 2.2 1.25 nm

Side dimorphism: Side dimorphism in otoliths

of Atherestes is only mildly developed. Otoliths of

the eyed side are slightly more compressed. Os-

tium and cauda are less clearly differentiated,

almost completely fused.

Ontogeny and variability: Smaller specimens

below 6.5 to 7 mm length are more rounded in

outline and the otolith rims are more densely

crenulated. Variability on the other hand seems

to be restricted to very minor details only.

Discussion: Otoliths of the genus Atherestes prob-

ably show the most elongate otoliths in this group

with the least side dimorphism.

Species and distribution: Two species – A. sto-

mias from the Pacific coast of North America, from

the Bering Sea to San Francisco, and A. evermanni

from Japan.

Atherestes stomias

(JORDAN & GILBERT 1881)

Figs. 493-497

Investigated otoliths: 6 otoliths (left and right)

from off California, ZMH Ot. 21.1.1995.9-14 (leg.

Fitch).

Discussion: Otoliths of A. stomias do not differ

greatly from those of A. evermanni. They are slight-

ly more elongate and the proportions of the sul-

cus are slightly different.

Distribution: North America, Bering Sea to San

Francisco, fossil from the Pleistocene of Califor-

nia.

Atherestes evermanni

JORDAN & STARKS 1904

Figs. 498-500

Investigated otoliths: 3 otoliths (2 left side and

1 right side) from Japan, ZMH Ot. 21.1.1995.15-

16 (leg. BMNH 1923.9.28.2-4) and BMNH

1923.9.28.2-4.

Discussion: See entry to A. stomias.

Distribution: Japan.

215

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Cleisthenes JORDAN & STARKS 1904

Type-species: Cleisthenes pimetorum JORDAN &

STARKS 1904

syn. Protopsetta Jordan & STARKS 1906 (type-

species: Hippoglossoides herzensteini)

Diagnosis: Thin, rather compressed otoliths;

ventral rim deeply and gently curving, deepest

at about the middle, dorsal rim with prominent

and somewhat projecting postdorsal and predor-

sal angles, faintly undulating, posterior tip blunt,

ventrally rounded, dorsally concave, anterior tip

slightly projecting like a rostrum, rounded. In-

dex l:h 1.25 to 1.4. Otolith size at least 7 mm.

Ostium wider than cauda and much longer.

Index ol:cl 1.6 to 2.0. Ostial opening strongly re-

duced. Cauda short, with rounded termination

at considerable distance from the posterior rim of

the otolith. Colliculi well separated and some-

what deepened. Circumsulcal depression com-

pletely connected and rather wide.

Inner face almost entirely flat, smooth; outer

face flat, rather smooth. Rims sharp.

Figs. 493-497: Atherestes stomias (JORDAN & GILBERT 1881) – 6 ×

Figs. 498-500: Atherestes evermanni JORDAN & STARKS 1904 – 6 ×

494

493a

493b

493c

496

497

498b

495

500

498a

499

498c

216

Schwarzhans: Pleuronectiformes

Measurements:

l:h h:t ol:cl oh:ch con.i

herzensteini 1.25-140 4.5 1.70-2.00 1.25-1.45 nm

Side dimorphism: Rather inconspicuous. Oto-

liths of the eyed side show a less pronounced

predorsal angle, and ostium and cauda are less

clearly differentiated.

Variability: Variability of otoliths of this genus

is very low, restricted to details of the marginal

ornamentation.

Discussion: Otoliths of the genus Cleisthenes re-

semble those of Atherestes, but are more com-

pressed and show a very typical development of

the dorsal rim

Species and distribution: Two species (some-

times regarded as subspecies of a single species

only) – C. herzensteini from the Okhotsk Sea to

Japan, Korea and northern China and C. pimeto-

rum from Japan.

Cleisthenes herzensteini (SCHMIDT 1904)

Figs. 501-504

Investigated otoliths: 4 otoliths (3 left side and

1 right side) from Toyama, Japan, ZMH Ot.

22.1.1995.1-3 (leg BMNH 1933.6.12.7 and BMNH

1931.9.18.9-10) and BMNH 1931.9.18.9-10.

Distribution: Okhotsk Sea, Japan, Korea and

northern China.

Lyopsetta JORDAN & GOSS 1887

Type-species: Hippoglossoides exilis JORDAN &

GILBERT 1887

Diagnosis: Moderately thin and moderately

elongate otoliths; ventral rim rather shallow, ir-

regularly curving, deepest somewhat behind the

middle, dorsal rim with postdorsal angle, slight-

ly undulating, posteriorly irregularly rounded,

anterior tip projecting like a rostrum, rounded.

Index l:h 1.3 to 1.5. Otolith size at least 5 mm. The

critical diagnostic size is reached with about

3.5 mm.

Ostium slightly wider than cauda and much

longer. Index ol:cl 1.7 to 2.0. Ostial opening strong-

ly reduced. Cauda short, with rounded termina-

tion at great distance from the posterior rim of

the otolith. Ostial and caudal colliculi well sepa-

rated and deepened. Sulcus relatively wide. Cir-

cumsulcal depression well developed and rather

wide and deep.

Inner face almost completely flat and rather

smooth; outer face slightly convex and smooth.

Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

exilis 1.30-1.50 3.0 1.70-2.00 1.0-1.2 nm

Figs. 501-504: Cleisthenes herzensteini (SCHMIDT 1904) – 6 ×

501b

501a

501c

504

503

502

217

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Side dimorphism: Side dimorphism in otoliths

of this genus again is not very strongly devel-

oped. Otoliths of the eyed side almost complete-

ly lack the differentiation of ostial and caudal

colliculi and the ostium is narrower, about the

width of the cauda only. Right hand otoliths are

more convex in the vertical direction.

Ontogeny and variability: Otoliths below

3.5 mm are more compressed and rounded in out-

line and show slightly more intense marginal

crenulation, thus not exhibiting all the pertinent

diagnostically important features. Variability on

the other hand is low and restricted to details of

the outline and the proportions.

Discussion: Otoliths of the genus Lyopsetta are

very similar to those of the genera Hippoglossoides

and Acanthopsetta. Especially differentiation from

Hippoglossoides is very feeble and judging from

otolith morphology alone may not warrant sep-

aration of the two genera.

Species and distribution: Lyopsetta is a mono-

specific genus with L. exilis restricted to the deeper

water of the Pacific coast of North America.

Lyopsetta exilis (JORDAN & GILBERT 1881)

Figs. 505-510

Investigated otoliths: 6 otoliths (left and right

side) from off California, ZMH Ot. 22.1.1995.4-9

(leg. Fitch).

Distribution: Pacific coast of North America,

from Alaska to San Francisco in rather deep wa-

ter; fossil from the Upper Pliocene and Pleistocene

of California.

Figs. 505-510: Lyopsetta exilis JORDAN & GILBERT 1881) – 10 ×

510

505a

505b

505c

507

506b

509

506a

508

218

Schwarzhans: Pleuronectiformes

Acanthopsetta SCHMIDT 1904

Type-species: Acanthopsetta nadeshnyi SCHMIDT

1904

Diagnosis: Thin, moderately elongate otoliths;

ventral rim shallow, gently curving, deepest be-

hind the middle, dorsal rim with rounded post-

dorsal angle, otherwise smooth and gently curv-

ing, posterior tip blunt, projecting strongest ven-

trally and with notch towards the postdorsal

angle, anterior tip projecting like a rostrum, round-

ed. Index l:h about 1.4. Otolith size at least 6 mm.

Ostium slightly wider than cauda and some-

what longer. Index ol:cl 1.3. Ostial opening strong-

ly reduced. Cauda short, with rounded termina-

tion at considerable distance from the posterior

rim of the otolith. Colliculi well separated and

rather strongly deepened. Circumsulcal depres-

sion completely connected, rather deep and ex-

tremely wide, reaching close to the margins of

the otolith.

Inner face almost completely flat and rather

smooth; outer face slightly convex and smooth.

Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

nadeshnyi 1.40 3.1 1.30 1.25 nm

Side dimorphism: No data.

Discussion: Otoliths of the genus Acanthopsetta

closely resemble those of the genera Hippoglos-

soides and Lyopsetta but differ in the development

of the posterior rim.

Species and distribution: Acanthopsetta is a

monospecific genus with A. nadeshnyi known

from the Okhotsk Sea to Japan and Korea.

Acanthopsetta nadeshnyi SCHMIDT 1904

Fig. 511

Investigated otoliths: 1 otolith (left side) from

Petropavlovsk, Kamchatka, BMNH 1923.11.21.6.

Distribution: Sea of Okhotsk to Japan and Korea.

Hippoglossoides GOTTSCHE 1835

Type-species: Hippoglossoides limanda GOTT-

SCHE 1835 (H. platessoides limandoides)

syn. Drepanopsetta GILL 1861 (type-species: Pleu-

ronectes platessoides platessoides)

syn. Pomatopsetta GILL 1864 (type-species: Pla-

tessa dentata, syn. H. platessoides platessoides)

syn. Cynopsetta JORDAN & STARKS 1906 (type-

species: Hippoglossoides dubius)

Diagnosis: Thin, roundish to moderately elon-

gate otoliths; ventral rim moderately deep, gen-

tly curving, deepest at or slightly behind the

middle, dorsal rim with postdorsal angle, some-

what undulating, posterior tip blunt, sometimes

slightly projecting ventrally, often irregularly

undulating, anterior tip somewhat projecting like

a rostrum, rounded. Index l:h 1.25 to 1.5. Otolith

size at least 9 mm. Otoliths smaller than 4 mm

may not have developed all pertinent diagnostic

features.

Fig. 511: Acanthopsetta nadeshnyi SCHMIDT 1904 – 10 ×

219

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ostium wider than cauda and much longer.

Index ol:cl 1.9 to 2.2. Ostial opening strongly re-

duced. Cauda short, with rounded termination

at considerable distance from the posterior rim of

the otolith. Sulcus very short, relatively wide.

Colliculi clearly separated and considerably deep-

ened. Circumsulcal depression completely con-

nected, moderately deep and very wide.

Inner face almost completely flat and rather

smooth; outer face slightly convex and smooth

too. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

platessoides 1.30-1.40 3.3 2.00-2.20 1.1-1.3 nm

elassodon 1.35-1.50 4.0 2.00-2.20 1.1-1.5 nm

dubius (left) 1.25-1.35 3.2 1.9-2.2 1.5-1.8 nm

dubius (right) 1.20 4.0 (2.5) 1.1 nm

Side dimorphism: In H. platessoides and H. elas-

sodon side dimorphism of the otoliths is rather

inconspicuous. The only obvious dimorphism is

the fact that otoliths of the eyed side show a less

clear separation of ostium and cauda and a some-

what more narrow sulcus. In H. dubius these two

characters are developed much more dimor-

phous. In addition, the shape of the otolith of the

eyed side is more roundish and the anterior-ven-

tral rim shows an intense crenulation. This kind

of dimorphism resembles the extreme side di-

morphism observed in the otoliths of the genus

Reinhardtius (see respective entry).

Ontogeny and variability: Otoliths smaller than

4 mm tend to be more roundish and less charac-

teristic. Variability is moderate, mainly restricted

to variations in the expression of dorsal and pos-

terior rims and some of the otolith and sulcus

proportions.

Discussion: Otoliths of the genus Hippoglossoides

closely resemble those of the related genera Acan-

thopsetta and Lyopsetta, and it must be doubted

whether the few differences observed in otolith

morphology are stable enough to support their

separation in three different genera. The aberrant

otoliths of Reinhardtius also resemble to a certain

extent, in particular the otoliths of H. dubius (for

detailed discussion see entry to Reinhardtius).

Species and distribution: Four species and two

subspecies – H. platessoides from the North Atlan-

tic, with one subspecies along the North Ameri-

can shores and another in the North-East Atlan-

tic, and H. elassodon, H. dubius and H. robustus in

the North Pacific.

Hippoglossoides platessoides FABRICIUS 1780

Figs. 512-515

syn. Pleuronectes limandoides BLOCH 1787 [sub-

species]

syn. Hippoglossoides limanda GOTTSCHE 1835

syn. Hippoglossoides dentatus STORER 1839

Investigated otoliths: 4 otoliths (left and right)

from the North Sea, ZMH Ot. 22.1.1995.10-13 (coll.

Schwarzhans).

Discussion: Very similar to H. elassodon from the

North Pacific but slightly more compressed and

with a more massive anterior tip.

Distribution: Two subspecies – H. p. platessoides

(FABRICIUS 1780) from the northern Atlantic

coast of the USA and H. p. limandoides (BLOCH

1787) from the coasts of north-western Europe.

The investigated specimens from the North Sea

belong to the latter subspecies. Also known as

fossil from the Pleistocene of Belgium.

Hippoglossoides elassodon

JORDAN & GILBERT 1881

Figs. 516-519

Investigated otoliths: 4 otoliths (left and right)

from Alaska, ZMH Ot. 22.1.1995.14-17 (leg. Fitch).

Discussion: Closely related to H. platessoides (see

respective entry).

Distribution: Northern Pacific coast of North

America and Sea of Okhotsk.

Hippoglossoides dubius SCHMIDT 1904

Figs. 520-523

syn. Hippoglossoides katakurae SNYDER 1911

Investigated otoliths: 4 otoliths, 2 (left and right,

figs. 520-521) from Wakkanai, Hokkaido, Japan,

coll. Ohe No. 811212, and 2 (left and right, figs.

522-523) from Owase, Mie prefecture, Japan, coll.

Ohe No. 760828.

220

Schwarzhans: Pleuronectiformes

Discussion: Otoliths of this species are remark-

able for their strong side dimorphism. Left oto-

liths (from the blind side) show a more elongate

outline, a much wider sulcus and a clear separa-

tion of the two colliculi. Also the sulcus is ex-

tremely short.

Distribution: Southern Okhotsk Sea to Japan and

Korea.

Reinhardtius GILL 1861

Type-species: Pleuronectes cynoglossus sensu FAB-

RICIUS 1780 (syn. R. hippoglossoides)

syn. Platysomatichthys BLEEKER 1862 (type-spe-

cies: Pleuronectes pinguis, syn. R. hippoglos-

soides)

Remarks: Otoliths of the genus Rheinhardtius are

probably the ones with the most drastic side di-

morphism. This necessitates a separate descrip-

tion of left (blind side) and right (eyed side) spec-

imens (replacing the chapter on side dimor-

phism). Amazingly, Reinhardtius is one of two flat-

fishes known to be swimming in an upright po-

sition (the other one being the “primitive” Pset-

todes). In the case of Reinhardtius this is clearly an

adaption to its role as an active predator in the

open sea. Why this way of living has resulted in

such an extreme development of side dimorphism

in otoliths at this stage remains unresolved.

Diagnosis (left, blind side): Very thin, moder-

ately elongate otoliths; ventral rim deeply curv-

ing, with pronounced midventral angle, dorsal

rim with pronounced postdorsal and slightly less

pronounced predorsal angle, intensely furcate,

posterior rim blunt, nearly vertically cut, with

deeply serrated ornamentation, sometimes devel-

oped to form fenestrae, anterior tip strongly pro-

jecting like a rostrum, not much rounded. Index

l:h 1.4 to 1.5. Otolith size at least 15 mm.

Ostium very much wider than cauda and

much longer, too. Index ol:cl about 3.0. Ostial

opening reduced. Cauda extremely short, round-

Figs. 512-515: Hippoglossoides platessoides FABRICIUS 1780 – 6 ×

Figs. 516-519: Hippoglossoides elassodon JORDAN & GILBERT 1881 – 6 ×

519

512a

512b

512c

516c

516b

518

517

513

515

514

516a

221

Piscium Catalogus, Part Otolithi piscium, Vol. 2

ish, terminating very far from the posterior rim

of the otolith. Sulcus shallow, except for a small

portion in the rear area of the ostium, which is

slightly deepened. Circumsulcal depression well

developed, very wide and somewhat deepened.

Inner face completely flat, even slightly con-

cave in cases, showing some concentrical growth

furrows in the circumslucal depression and dor-

sally and posteriorly some radial furrows origi-

nating from the marginal ornamentation; outer

face flat, with some radial furrows. Rims sharp.

(Right, eyed side): Very thin, rather compressed

otoliths; ventral rim deeply and regularly curv-

ing, deepest at about the middle, anterior-ventral

portion strongly serrated, sometimes with devel-

opment of fenestrae, dorsal rim with equally

pronounced pre- and postdorsal angles, smooth,

posterior rim blunt or broadly rounded, smooth,

anterior tip strongly projecting like a rostrum,

rounded. Index l:h 1.25 to 1.35. Otolith size at

least 15 mm.

Ostium and cauda practically completely

fused, including the colliculi, which anteriorly

are elevated and posteriorly somewhat deepened.

Sulcus as a whole rather narrow, long, and except

for the colliculi very poorly defined. Ostial open-

ing reduced, but reaching relatively close to the

anterior rim of the otolith. Cauda terminating not

very far from the posterior rim of the otolith.

Circumsulcal depression well developed only in

the posterior portion, there very wide and some-

what deepened.

Inner face flat, but with ventral portion some-

what bent outward, smooth except for few radial

furrows originating from the marginal ornamen-

tation; outer face flat to slightly concave, with

some radial furrows. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

hippoglossoides (l.)1.40-1.50 5.5 about 3.0 about 3.0 nm

hippoglossoides (r.)1.25-1.35 5.5 nm nm nm

Figs. 520-523: Hippoglossoides dubius SCHMIDT 1904 – 6 ×

520a

520b

520c

521c

523

521a

522b

521b

522a

222

Schwarzhans: Pleuronectiformes

Side dimorphism: See above (diagnosis and re-

marks).

Variability: Overall variability is moderate. The

intensity of the ornamentation of the rims of the

otoliths and the development of “fenestrae” are

apt to some variations

Discussion: NORMAN (1934) related Reinhard-

tius to Atherestes. Otoliths of the “less altered”

blind side indeed suggest a relationship of Rein-

hardtius to the genera of the Hippoglossoides Group,

in which I have also placed Atherestes. The high

degree of otolith specialization, however, ham-

pers any detailed interpretation. Nevertheless, it

seems that in certain species of the genus Hip-

poglossoides (H. dubius, see respective entry) the

kind of extreme side dimorphism of otoliths found

in Reinhardtius is “foreshadowed” to a certain

degree. I therefore tend to relate Reinhardtius closer

to Hippoglossoides than to Atherestes.

Species and distribution: Reinhardtius is a mon-

ospecific genus with R. hippoglossoides occurring

pelagically in the Northern Atlantic and the

Northern Pacific. Specimens caught in the North-

ern Pacific have originally been described as a

distinct species (R. matsuurae), but NORMAN

(1934) already suggested them to represent an

identical species. Otoliths available from fishes

of both regions clearly support his view.

Reinhardtius hippoglossoides

(WALBAUM 1792)

Figs. 524-528, 20

syn. Pleuronectes cynoglossus (non LINNAEUS)

sensu FABRICIUS 1780

syn. Pleuronectes pinguis FABRICIUS 1824

syn. Reinhardtius matsuurae JORDAN & SNYDER

1901

Investigated otoliths: 5 otoliths, 2 (left and right,

figs. 526-527) from off Hokkaido, Japan, IRSNB

(coll. Nolf), 1 (left, fig. 528) from of New Found-

land, IRSNB (coll. Nolf), 2 (right, fig. 524-525) from

off Greenland, ZMH Ot. 22.1.1995.18-19 (leg.

Fitch).

Distribution: Pelagic in deeper waters of the

northern North Atlantic and the North Pacific.

7.7.3 Glyptocephalus Group

Genera: Two genera – Tanakius and Glyptocephalus.

Definition and relationship: The Glyptocephalus

Group no doubt is closely related to the preced-

ing Hippoglossoides Group and probably represents

a specialized offshot from it. Its otoliths merely

differ from those of the Hippoglossoides Group in

its more gently curving outline and the more

compressed appearance (particularly the genus

Glyptocephalus). NORMAN (1934) related them

instead to Limanda and related genera (e.g. Dex-

istes) based on the small and asymmetrical mouth

which they share with these genera and which he

used as one of the main features for grouping the

various genera in his Pleuronectinae (see general

discussion to Pleuronectidae). In this particular

case, this characterization does not seem to hold

and otoliths clearly point to a closer relationship

with the Hippoglossoides Group.

Tanakius HUBBS 1918

Type-species: Microstomus kitaharae JORDAN &

STARKS 1904

Diagnosis: Moderately thin, ovale otoliths; ven-

tral and dorsal rims shallow and gently curving,

without prominent angles or ornamentation,

posterior and anterior rims broadly rounded.

Index l:h 1.6. Otolith size at least 4 mm.

Ostium slightly wider than cauda and much

longer. Index ol:cl 2.0. Ostial opening reduced.

Colliculi well separated and deepened. Cauda

short, round, terminating at some distance from

the posterior rim of the otolith. Sulcus rather wide,

moderately short. Circumsulcal depression well

developed, wide and somewhat deepened.

Inner face flat, smooth; outer face slightly

convex and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

kitaharae 1.60 3.2 2.00 1.2 4

Side dimorphism: No data.

Discussion: Otoliths of the genus Tanakius are

readily distinguished of those of the related ge-

nus Glyptocephalus in being more elongate. They

probably represent the more plesiomorphic char-

acter status.

223

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Species and distribution: Tanakius is a mono-

specific genus with T. kitaharae restricted to the

waters of Japan and Korea.

Tanakius kitaharae JORDAN & STARKS 1904

Fig. 529

Investigated otoliths: 1 otolith (left side) from

Japan, BMNH 1923.11.21.19.

Distribution: Southern Japan and Korea.

Figs. 524-528: Reinhardtius hippoglossoides (WALBAUM 1792) – 6 ×

524a

524b

524c

526

525

528b

527a

528a

527c

528c

527b

224

Schwarzhans: Pleuronectiformes

Glyptocephalus GOTTSCHE 1835

Type-species: Pleuronectes saxicola FABER 1828

(syn. G. cynoglossus)

syn. Errex JORDAN 1919 (type-species: Glypto-

cephalus zachirus)

Diagnosis: Moderately thin, almost perfectly

round otoliths; all rims gently curving, sometimes

slightly undulating, otherwise smooth, postdor-

sal and sometimes also predorsal angle weekly

developed. Index l:h 1.0 to 1.25. Otolith size at

least 8 mm, but otoliths of about 4.5 mm already

diagnostically mature.

Ostium wider than cauda and somewhat long-

er. Index ol:cl 1.4 to 1.6. Ostial opening reduced.

Cauda short, round, terminating at some distance

from the posterior rim of the otolith. Colliculi well

separated and deepened. Sulcus moderately wide

and short. Circumsulcal depression well devel-

oped, wide, but not very deep..

Inner face practically flat, smooth, except for

few thin radial furrows to be seen within the cir-

cumsulcal depression; outer face slightly convex,

rather smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.o

cynoglossus 1.00 4.0 1.5 1.2 3.2

zachirus 1.10-1.25 3.3 1.4-1.5 1.1-1.4 2.8

Side dimorphism: Side dimorphism in otoliths

of the genus Glyptocephalus is quite strongly de-

veloped. First of all, otoliths of the eyed side dif-

fer from those of the blind side in the completely

fused colliculi (intrasulcal proportions listed

above therefore are only valid for left hand oto-

liths). The sulcus is also narrower in otoliths from

the eyed side and within the circumsulcal de-

pression radial furrows are much more common.

Also the rear part of the circumsulcal depression

is more deepened, sometimes showing concen-

tric growth lines.

Ontogeny and variability: A single large speci-

men obtained from G. zachirus does not differ

greatly from the smaller ones, except for being

slightly more elongate and showing a more

rounded outline than smaller specimens of the

same species. Likewise, variability seems to be

restricted to minor variations of the outline.

Discussion: Otoliths of the genus Glyptocephalus

are readily recognized by their compressed,

roundish outline.

Species and distribution: Three species from the

North Atlantic and North Pacific – G. cynoglos-

sus, G. zachirus and G. stelleri.

Glyptocephalus cynoglossus

(LINNAEUS 1758)

Figs. 530-531

syn. Pleuronectes saxicola FABER 1828

syn. Pleuronectes nigromanus NILSSON 1829

syn. Platessa elongata YARELL 1839

syn. Glyptocephalus acadianus GILL 1873

Investigated otoliths: 2 otoliths (left and right)

from the North Atlantic, Meteor St. 2017, ZMH

Ot. 23.1.1995.1-2 (leg. W. Schmidt).

Discussion: Although otoliths of the Glyptoceph-

alus species do not differ much from each other,

those of G. cynoglossus may be recognized as the

most compressed ones.

Distribution: On both sides of the North Atlantic.

Glyptocephalus zachirus LOCKINGTON 1878

Figs. 532-538, 22

Investigated otoliths: 5 otoliths (2 left and 3 right,

figs. 532-536) from off California, ZMH Ot.

23.1.1995.3-7 (leg. Fitch), and 2 otoliths (left and

right, figs. 537-538) as G. aff. zachirus (identified

Fig. 529: Tanakius kitaharae

JORDAN & STARKS 1904 – 10 ×

225

Piscium Catalogus, Part Otolithi piscium, Vol. 2

as Brachypleura novaezeelandiae probably due to

mistake in jar labels) from the ZMH collection,

ZMH 20010.

Discussion: Otoliths of G. zachirus are slightly

more elongate than those of G. cynoglossus.

Distribution: Pacific coast of North America,

from the Bering Sea to San Francisco; fossil from

the Pleistocene of California.

7.7.4 Pleuronectes-Limanda Group

Genera: 9 genera – Limanda, Dexistes, Liopsetta,

Parophrys, Pleuronectes, Platichthys, Kareius, Pseudo-

pleuronectes, Lepidopsetta and Inopsetta – distrib-

uted in the northern Atlantic and the northern

Pacific.

Definition and relationship: This group com-

bines the bulk of the genera placed by NORMAN

(1934) in the category of Pleuronectinae with a

small and asymmetrical mouth.

Their otoliths are typically elongate and thin

to very thin, usually with a pronounced postdor-

sal angle and a very smooth inner face. The sul-

cus is relatively long and shallow. The ostial open-

ing is quite reduced. The cauda is much shorter

than the ostium and terminates at considerable

distance from the posterior rim of the otolith.

Although forming a dense unit in respect to

the otolith morphology this group could be sub-

divided into two smaller subgroups. One sub-

group would cluster around Limanda (including

Dexistes and Liopsetta). These otoliths are more

gently curving in outline and their sulcus is more

structured. In this respect they show a certain

resemblance to otoliths of the Hippoglossoides and

Figs. 530-531: Glyptocephalus cynoglossus (LINNAEUS 1758) – 6 ×

Figs. 532-536: Glyptocephalus zachirus LOCKINGTON 1878 – 6 ×

530c

530a

530b

532a

532c

531

533

532b

534

536

535

226

Schwarzhans: Pleuronectiformes

even the Glyptocephalus Groups. All the other

genera clustering around Pleuronectes seem to be

very closely related to each other and distinction

of the genera by means of otoliths is not always

easy. They show better resemblance to the Hip-

poglossus Group (in particular the genus Eopset-

ta). I assume the Pleuronectes-Limanda Group to

be basically related to the Hippoglossus and may

be also the Hippoglossoides Group.

Limanda GOTTSCHE 1835

Type-species: Pleuronectes limanda LINNAEUS

1758

syn. Myzopsetta GILL 1864 (type-species: Platessa

ferruginea STORER 1839)

Diagnosis: Thin, moderately elongate to round-

ish otoliths; ventral rim gently curving, deepest

at about the middle, dorsal rim with rounded

postdorsal angle, often somewhat undulating,

posterior tip blunt to irregularly rounded, anteri-

or tip slightly projecting like a rostrum, rounded.

Index l:h 1.25 to 1.6. Otolith size at least 5 mm.

Diagnostic size reached at about 3 to 3.5 mm.

Ostium not much wider than cauda, but con-

siderably longer. Index ol:cl 1.9 to 2.4. Ostial open-

ing reduced. Cauda short, rounded, terminating

at some distance from the posterior rim of the

otolith. Sulcus relatively shallow. Circumsulcal

depression completely connected and wide, but

rather shallow.

Inner face rather flat and smooth; outer face

completely flat, smooth or faintly ornamented.

Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

limanda 1.50-1.60 4.0 1.90-2.25 1.0-1.2 about 9

aspera 1.30-1.40 3.2 2.0-2.4 1.1-1.3 about 5

ferruginea 1.25-1.30 3.8 2.3-2.6 1.1-1.2 3.5

†ignobilis 1.40 4.2 2.1 1.2 about 5

Side dimorphism: Side dimorphism in the spe-

cies of the genus Limanda is only feeble. Otoliths

of the eyed side show a slightly stronger postdor-

sal angle and the colliculi are less well separated.

Ontogeny: Smaller specimens, particularly be-

low 3.5 to 3 mm are somewhat more gently round-

ed in outline and its rims are much more intense-

ly crenulated.

Discussion: Otoliths of Limanda show the clos-

est resemblance to those of Dexistes, the latter

merely differing in a more elongate shape, an

almost completely flat inner face and a somewhat

deeper sulcus.

Species and distribution: 6 recent species –

L. limanda and L. ferruginea from the North Atlan-

tic, and L. aspera, L. punctatissima, L. proboscidea

and L. sakhalinensis from the North Pacific. Liman-

da is also one of the very few Pleuronectid genera

known from a fossil otolith based species –

L. ignobilis from the Upper Oligocene of northern

Germany.

Limanda limanda (LINNAEUS 1758)

Figs. 539-541

syn. Pleuronectes limandula BONATERRE 1788

syn. Limanda vulgaris GOTTSCHE 1835

syn. Limanda oceanica BONAPARTE 1846

Investigated otoliths: 3 otoliths, 2 (right side,

figs.) form the North Sea, ZMH Ot. 23.1.1995.8-9

(coll. Schwarzhans) and 1 (left side, fig. ) (as L. fer-

ruginea) from Iceland, ZMH Ot. 23.1.1995.10 (leg.

ZMUC 853359-61).

Discussion: Of all the species investigated from

this genus the otoliths of L. limanda are the most

elongate.

Distribution: Coasts of north-western Europe

and Iceland; fossil from the Pleistocene of Bel-

gium and southern England.

Figs. 537-538: Glyptocephalus aff. zachirus

LOCKINGTON 1878 – 6 ×

537a

537b

538

227

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Limanda aspera (PALLAS 1814)

Figs. 542-544

syn. Limanda asprella HUBBS 1915

Investigated otoliths: 3 otoliths (1 left and 2 right)

from the Bering Sea, ZMH Ot. 23.1.1995.11-13 (leg.

Fitch).

Discussion: Otoliths of L. aspera are more com-

pressed than those of L. limanda, but less than

those of L. ferruginea.

Distribution: Bering Sea to Vancouver Island and

Korea.

Limanda ferruginea (STORER 1839)

Figs. 545-548

syn. Myzopsetta rostrata GILL 1861

Investigated otoliths: 4 otoliths (left and right)

from Iceland, ZMH Ot. 23.1.1995. 14-17 (leg.

ZMUC 853359-61).

Discussion: L. ferruginea shows the most com-

pressed otoliths within this genus, and with the

smallest cauda. Otolith margins are relatively

intensely crenulated.

Distribution: Atlantic coast of North America,

from Labrador to New York, and eastward to

Iceland.

Limanda ignobilis SCHWARZHANS 1994

Fig. 549

Investigated otoliths: The unique holotype from

the uppermost Oligocene (Chatt C) of Krefeld,

northern Germany, GPIM-M 2916 (leg. von der

Hocht).

Discussion: This fossil species differs from the

recent ones mainly in the longer sulcus which

reaches somewhat closer to the anterior tip of the

otolith.

Distribution: Upper Oligocene of northern Ger-

many.

Dexistes JORDAN & STARK 1904

Type-species: Dexistes rikuzenius JORDAN &

STARKS 1904

syn. Araias JORDAN & STARKS 1904 (type-spe-

cies: A. ariommus, syn. D. rikuzenius)

Diagnosis: Moderately thin and rather elongate

otoliths; ventral rim shallow, gently curving, deep-

est at about the middle, dorsal rim without prom-

inent postdorsal angle, but rounded predorsal

projection, slightly undulating, posterior tip

rounded, anterior tip slightly projecting like a

rostrum, rounded. Index l:h 1.7 to 1.8. Otolith

size at least 6 mm.

Ostium slightly wider than cauda and much

longer. Index ol:cl 1.9 to 2.0. Ostial opening re-

duced. Cauda short, with rounded termination

at some distance from the posterior rim of the

Figs. 539-541: Limanda limanda (LINNAEUS 1758) – 10 ×

539c

539a

539b

540

541

228

Schwarzhans: Pleuronectiformes

otolith. Colliculi separated, sulcus slightly deep-

ened. Circumsulcal depression well developed,

wide and somewhat deepened.

Inner face completely flat, smooth; outer face

slightly convex and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.o

rikuzenius 1.70-1.80 2.7 1.90-2.00 1.05-1.3 3.4

Side dimorphism: No data.

Discussion: Very similar to Limanda (see respec-

tive entry).

Figs. 542-544: Limanda aspera (PALLAS 1814) – 10 ×

Figs. 545-548: Limanda ferruginea (STORER 1839) – 10 ×

Fig. 549: Limanda ignobilis SCHWARZHANS 1994 –

15 ×

545c

544a

544b

542

543

546

545a

545b

548

547

229

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Species and distribution: Dexistes is a monospe-

cific genus with D. rikuzenius known from the

shores of Japan.

Dexistes rikuzenius JORDAN & STARKS 1904

Figs. 550-551

syn. Araias ariommus JORDAN & STARKS 1904

Investigated otoliths: 2 otoliths (left side) from

Japan, ZMH Ot. 23.1.1995.18 (leg. BMNH

1933.6.12.14) and BMNH 1933.6.12.14.

Distribution: Coasts of Japan.

Liopsetta GILL 1864

Type-species: Platessa glabra (non RATHKE) sen-

su STORER 1844, syn. L. putnami

syn. Euchalarodus GILL 1864 (type-species: Pleuro-

nectes obscurus)

Diagnosis: Moderately thin and moderately

elongate otoliths; ventral rim very shallow, gen-

tly curving, deepest at about the middle, dorsal

rim with postdorsal angle, slightly undulating,

posterior tip blunt, with somewhat projecting

posterior-ventral corner, anterior tip blunt, with

faint rostrum like projection. Index l:h 1.55 to 1.75.

Otolith size at least 6 mm.

Ostium slightly to considerably wider than

cauda and longer. Index ol:cl 1.3 to 1.6. Ostial

opening reduced. Cauda short, roundish, termi-

nating at some distance from the posterior rim of

the otolith. Colliculi well separated, sulcus some-

what deepened. Circumsulcal depression

completely connected, rather narrow and not very

deep.

Inner face flat, not very smooth. Rims moder-

ately sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

putnami 1.55 3.4 1.60 1.75 nm

glacialis 1.60 3.6 1.40-1.60 1.15-1.45 about 7

obscurus 1.75 3.0 1.30 1.20 about 5

Side dimorphism: No data.

Variability: The two specimens of L. glacialis al-

ready indicate, that the variability in the species

of this genus probably is more considerable than

in other genera of the Pleuronectes-Limanda Group.

It concerns the expression of the posterior tip of

the otolith and proportions of the sulcus.

Discussion: The posterior-ventrally projecting

posterior rim in combination with the somewhat

deepened sulcus characterize otoliths of this genus.

Species and distribution: Four species – L. ob-

scura and L. pinnifasciata from the North Pacific,

L. putnami from the Atlantic coast of North Amer-

ica, and L. glacialis from the Arctic coasts of Sibe-

ria and Alaska.

Figs. 550-551: Dexistes rikuzenius JORDAN & STARKS 1904 – 10 ×

550c

550b

551

550a

230

Schwarzhans: Pleuronectiformes

Liopsetta putnami (GILL 1864)

Fig. 554

syn. Platessa glabra (non RATHKE) sensu STORER

1844

Investigated otoliths: 1 otolith (left side) from

off Massachusetts, USA, BMNH 1924.2.25.1.

Discussion: The otoliths of L. putnami are read-

ily recognized by their much widened ostium and

the more rounded dorsal rim.

Distribution: Atlantic coast of North America,

from Labrador to Cape Cod.

Liopsetta glacialis (PALLAS 1776)

Figs. 552-553

syn. Pleuronectes cicatricosus PALLAS 1814

syn. Platessa dwinensis LILLJEBORG 1851

Investigated otoliths: 2 otoliths (left side) from

off northern Alaska, ZMH Ot. 23.1.1995.19 (leg.

BMNH 1932.12.31.35-36) and BMNH 1932.12.31.

35-36.

Discussion: Similar to L. putnami, but with less

widened ostium.

Distribution: Arctic coasts of Siberia and Alaska.

Liopsetta obscurus (HERZENSTEIN 1891)

Fig. 555

Investigated otoliths: 1 otolith (left side) from

off Vladivostock, Russia, BMNH 1923.12.18.6-7.

Discussion: Otoliths of L. obscura are considera-

bly more elongate than those of the two other

species of the genus investigated.

Distribution: Okhotsk Sea, Sakhalin Island, Sea

of Japan, and Yellow Sea.

Figs. 552-553: Liopsetta glacialis (PALLAS 1776) – 10 ×

Fig. 554: Liopsetta putnami (GILL 1864) – 10 ×

Fig. 555: Liopsetta obscura (HERZENSTEIN 1891) – 10 ×

552c

552b

553

552a

555b

555a

554b

554a

231

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Parophrys GIRARD 1856

Type-species: Parophrys vetula GIRARD 1856

Diagnosis: Thin, elongate otoliths; ventral rim

shallow, gently curving, deepest at about the

middle, dorsal rim with postdorsal angle, some-

what undulating, posterior tip blunt, anterior tip

somewhat projecting like a rostrum, rounded.

Index l:h 1.65 to 2.0. Otolith size at least 10 mm.

Otoliths below 5 mm not diagnostically mature.

Ostium slightly wider than cauda and much

longer. Index ol:cl 2.15 to 2.65. Ostial opening

reduced. Cauda short, terminating at some dis-

tance from the posterior tip of the otolith. Sulcus

slightly deepened. Colliculi separated. Circum-

sulcal depression well developed, wide, slightly

deepened.

Inner face rather flat and smooth; outer face

also flat and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

vetula (left, adult) 2.00 3.5 2.65 1.6 about 10

vetula (right, adult) 1.70 3.8 2.50 1.35 about 10

vetula (left, juv.) 1.70 3.2 2.25 1.15 about 7

vetula (right, juv.) 1.65 3.3 2.25 1.20 about 5

Side dimorphism: Side dimorphism in this ge-

nus is moderate. It so seems that otoliths of the

eyed (right) side are somewhat more compressed

and show less well separated colliculi in the sul-

cus. In the vertical direction the inner face of oto-

liths of the eyed side is slightly more convex and

the area of the circumsulcal depression often

shows delicate radial furrows and concentrical

growth rings.

Ontogeny: Small specimens, particularly below

5 mm, are somewhat more compressed and a

show a more intense crenulation of the otolith

rims.

Discussion: Otoliths of the genus Parophrys re-

semble those of Eopsetta from the Hippoglossus

Group in general appearance. In fact, this could

point to a possible relationship. Genera of the

Pleuronectes-Limanda Group differ mainly in be-

ing less elongate.

Species and distribution: Parophrys is a mono-

specific genus with P. vetula restricted to the Pa-

cific coast of North America.

Parophrys vetula GIRARD 1856

Figs. 556-560, 19

syn. Pleuronectes diagrammus GÜNTHER 1862

syn. Parophrys hubbardi GILL 1863

Investigated otoliths: 5 otoliths (2 left and 3 right)

from off California, ZMH Ot. 24.1.1995.1-5 (leg.

Fitch).

Distribution: Pacific coast of North America,

from Sitka to Santa Barbara; fossil from the Pleis-

tocene of California.

Pleuronectes LINNAEUS 1758

Type-species: Pleuronectes platessa LINNAEUS

1758

syn. Platessa CUVIER 1817 (type-species: Pleu-

ronectes platessa)

Diagnosis: Thin, moderately elongate, ovale oto-

liths; ventral rim shallow, gently curving, deepest

at about the middle, often delicately crenulated,

dorsal rim with sharp postdorsal angle, some-

what undulating, posterior tip blunt, anterior tip

somewhat projecting like a rostrum, rounded.

Index l:h 1.45 to 1.6. Otolith size at least 7 mm.

Otoliths below 3 to 4 mm not diagnostically

mature.

Ostium slightly wider than cauda and much

longer. Index ol:cl 1.5 to 2.1. Ostial opening re-

duced. Cauda short, terminating at some distance

from the posterior tip of the otolith. Colliculi sep-

arated, but not very clearly though. Cauda slightly

deepened and also the anterior portion of the

ostium. Circumsulcal depression well developed,

not very wide, rather shallow.

Inner face slightly convex, rather smooth;

outer face flat and delicately ornamented. Rims

sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

platessa 1.45-16.0 4.0-5.0 1.50-2.10 1.05-1.15 6.5-8

Side dimorphism: Side dimorphism of the oto-

liths is not very strongly developed in Pleuronectes.

Otoliths of the blind (left) side often show a pe-

culiar deepening of the anterior portion of the

ostium, a rather unique character in Pleuronecti-

dae. Otoliths of the eyed (right) side may show a

232

Schwarzhans: Pleuronectiformes

less well developed separation of the colliculi and

a slightly more convex inner face.

In the case of Pleuronectes platessa I have stud-

ied the effects of side dimorphism in otoliths

during ontogeny starting from early bottom liv-

ing postlarval fishes of 30 to 60 mm length (se

also chapters 6.2 and 6.3) (figs.). These otoliths,

which are about 1.0 to 1.6 mm long, do not show

the kind of side dimorphism described above

from adults. Instead, there otoliths of the eyed

(right) side exhibit a more pronounced postdor-

sal projection of the otolith rim than otoliths of

the blind (left) side, a dimorphic character, which

apparently gets lost later in ontogeny.

Ontogeny and variability: The very small oto-

liths of postlarval stages (figs.) look like very

generalized pleuronectid otoliths and certainly

are not diagnostically mature. They are more

compressed and roundish in outline and their

rims less ornamented. The sulcus opening, how-

ever, is already reduced and the circumsulcal de-

pression completely developed. It seems that di-

agnostic maturation of the otoliths is reached at

about 4 mm of size.

Discussion: The oval outline with the gently

curving ventral rim and the peculiar deepening

of the anterior portion of the ostium in otoliths of

the blind (left) side characterizes otoliths of this

genus.

In a recent review of the Pleuronectidae

SAKAMOTO (1984) has synonymized a number

of genera with Pleuronectes. These are Isopsetta,

Parophrys, Lepidopsetta, Limanda, Pseudopleuronectes

and Liopsetta. Except for Isopsetta, which is quite

Figs. 556-560: Parophrys vetulus GIRARD 1856 – 6 ×

556c

556b

556d556a

557a

557d

557c

558

557b

560a

560b

559a

559c

559b

560c

233

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Figs. 561-569: Pleuronectes platessa LINNAEAUS 1758 – figs. 561a, 562a, 563-567, 568c, 569c = 10 ×; figs. 561b,c,

562b,c = 6 ×; figs. 568a, b, 569a, b = 15 ×

561a

562b

561c

561b

566

568b

564

562c

562a

565

569c

568c

563

568a

567

569b

569a

234

Schwarzhans: Pleuronectiformes

distinct as far as otoliths are concerned, these

genera are here placed in the Pleuronectes-Limanda

Group and undoubtedly are closely interrelated

with each other. Indeed, it seems that generic

splitting may have been driven to far in this group,

but with the present state of knowledge I do not

feel in the position to comment on the basis of

otoliths.

Species and distribution: two species – P. platessa

from the north-eastern Atlantic and P. pallasii from

the northern, Arctic Pacific.

Pleuronectes platessa LINNAEUS 1758

Figs. 561-569

syn. Platessa vulgaris CLOQUET 1826

syn. Pleuronectes borealis FABER 1828

syn. Platessa lata CUVIER 1829

syn. Pleuronectes baltica NILSSON 1855

Investigated otoliths: 12 otoliths (left and right)

from the North Sea, ZMH Ot. 24.1.1995.6-17 (coll.

Schwarzhans).

Distribution: North-western Europe, from the

White Sea to Spain, Iceland, and in the Adriatic;

also as fossil from the Pleistocene of southern

England.

Platichthys GIRARD 1856

Type-species: Platichthys rugosus GIRARD 1856

(syn. P. stellatus)

syn. Flesus MOREAU 1881

Diagnosis: Thin, rather elongate otoliths; ven-

tral rim shallow, gently curving, deepest at about

the middle, dorsal rim with prominent postdor-

sal angle, slightly undulating, posterior tip blunt,

anterior tip somewhat projecting like a rostrum,

rounded. Index l:h 1.55 to 1.85. Otolith size at

least 6 mm. Otoliths below 3 mm not diagnosti-

cally mature.

Ostium slightly wider than cauda and much

longer. Index ol:cl 2.0 to 2.6. Ostial opening re-

duced. Cauda short, terminating at some distance

from the posterior tip of the otolith. Sulcus slight-

ly deepened. Colliculi separated. Circumsulcal

depression well developed, moderately wide,

slightly deepened.

Inner face slightly convex and rather smooth;

outer face flat and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

flesus 1.55-1.70 3.2 2.00-2.50 1.35-1.55 5.5-8

stellatus 1.65-1.85 3.2 2.50-2.60 1.5 about 5

Side dimorphism: Side dimorphism is moder-

ately developed in this genus. The separation of

the colliculi is less well developed in otoliths of

the eyed (right) side, the inner face slightly more

convex, the circumsulcal depression more shal-

low, and the postdorsal projection more pointed.

Determination of side dimorphism in the oto-

liths of this genus is hampered by the common

occurrence of reversed specimens. In particular

in P. stellatus it has been noted that specimens

from the North-West Pacific are almost always

reversed, whereas in the North-East Pacific re-

versed and non-reversed specimens occur in

about equal amounts. Reversal bears a strong

impact in the otolith morphology, and this is being

discussed in detail in chapter 6.4.

Ontogeny and variability: Otoliths of a size

down to about 3 mm do not differ greatly from

larger ones and can be regarded as diagnostically

mature. Variability is more considerable than in

other genera of the Pleuronectidae and mainly

concerns otolith and sulcus proportions. Again,

the effects of reversal on otolith morphology are

most notable.

Discussion: Otoliths of the genus Platichthys are

very similar to both the genera Kareius (placed in

synonymy with Platichthys by NORMAN 1934)

and Pleuronectes. NORMAN related this genus

also to Liopsetta.

Species and distribution: Two species – P. flesus

from the North Atlantic and the Mediterranean

and P. stellatus from the North Pacific.

Platichthys flesus (LINNAEUS 1758)

Figs. 570-572, 25

syn. Pleuronectes passer LINNAEUS 1758

syn. Pleuronectes flesoides PONTOPPIDAN 1765

syn. Pleuronectes roseus SHAW 1796

syn. Scophthalmus diurus RAFINESQUE 1810

syn. Pleuronectes luscus PALLAS 1814

235

Piscium Catalogus, Part Otolithi piscium, Vol. 2

syn. Platessa carnaria BROWN 1830

syn. Platessa glabra RATHKE 1837

syn. Pleuronectes passarinus NARDO 1847

syn. Pleuronectes italicus GÜNTHER 1862

syn. Pleuronectes bogdanovi SANDEBERG 1878

Investigated otoliths: 9 otoliths (4 left and 5 right,

including 4 from reversed specimens, figs. 571-

572, 25), 8 from Plymouth, Great Britain, ZMH

Ot. 24.1.1995.18-21 (leg. BMNH 1988.10.11.39-52)

and BMNH 1988.10.11.39-52, and 1 from Portu-

gal (fig. 570), ZMH Ot. 24.1.1995.22 (coll.

Schwarzhans).

Discussion: As a rule, otoliths of P. flesus are less

elongate than those of P. stellatus.

Distribution: Coasts of Europe, from the White

Sea to the Mediterranean and the Black Sea; also

as fossil from the Pleistocene of southern Eng-

land.

Platichthys stellatus (PALLAS 1787)

Figs. 573-574, 24

syn. Platichthys rugosus GIRARD 1856

Investigated otoliths: 12 otoliths, 2 (left and right,

non-reversed) from California, BMNH (Ayres

coll.), 2 (left and right, non-reversed, figs. 573-

574, 24) from California, ZMH Ot. 24.1.1995.23-

24 (leg. BMNH 81.3.14.13), 4 (left and right, re-

versed, fig. 24) from California, ZMH Ot.

24.1.1995.25-26 (leg. BMNH, Ayres coll.) and

BMNH, Ayres coll., 2 (left and right, reversed,

fig. 24) from Kamchatka, ZMH Ot. 24.1.1995.27-

28 (leg. BMNH 91.12.21.40), and 2 (left and right,

reversed, fig. 24) from the Rae’s collection, BMNH

53.9.19.1220.

Discussion: Otoliths of “normal”, non-reversed

specimens of P. stellatus differ from those of

P. flesus in being somewhat more elongate.

Distribution: North Pacific, Japan, Korea and

southern California; fossil from the Pleistocene

of California.

Kareius JORDAN & SNYDER 1901

Type-species: Pleuronectes scutifer STEINDACH-

NER 1870 (syn. K. bicoloratus)

Diagnosis: Thin, rather elongate otoliths; ven-

tral rim shallow, gently curving, deepest at about

the middle, dorsal rim with postdorsal angle,

posterior tip blunt, anterior tip somewhat pro-

jecting like a rostrum, rounded. All rims some-

what crenulated. Index l:h 1.5 to 1.75. Otolith size

at least 5 mm.

Ostium slightly wider than cauda and con-

siderably longer. Index ol:cl 1.75 to 1.9. Ostial

opening reduced. Cauda short, terminating at

some distance from the posterior tip of the oto-

lith. Sulcus very slightly deepened. Colliculi sep-

arated. Circumsulcal depression well developed,

moderately wide, slightly deepened.

Inner face rather flat and smooth; outer face

also flat and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

bicoloratus 1.50-1.75 3.0-3.5 1.75-1.90 1.05-1.25 5.5-6.5

Side dimorphism: Weekly developed. The sep-

aration of the colliculi is less well developed in

otoliths of the eyed (right) side. Also the postdor-

sal angle is more pointed and the ostium seem-

ingly more narrow.

Variability: The most variable character seems

to be the index l:h of the otolith.

Discussion: Kareius apparently is closely related

to Platichthys (placed in synonymy by NORMAN,

1934). Main difference is the lesser index ol:cl and

the fine marginal crenulation.

Species and distribution: Kareius is a monospe-

cific genus with K. bicoloratus known from the

coasts of Japan, Korea and northern China.

Kareius bicoloratus (BASILEWSKY 1855)

Figs. 575-578

syn. Pleuronectes scutifer STEINDACHNER 1870

Investigated otoliths: 4 otoliths (left and right)

from the Ise Bay, central Japan, coll. Ohe No.

751011-23

236

Schwarzhans: Pleuronectiformes

Figs. 570-572: Platichthys flesus (LINNAEUS 1758) – 10 ×

Figs. 573-574: Platichthys stellatus (PALLAS 1787) – 10 ×

570b

573a

571b

570a

570c

572c

570d

573b

571a

572b571c

573c

572a

574a

574c

574b

237

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Distribution: Japan, Korea and northern China.

Pseudopleuronectes BLEEKER 1862

Type-species: Pleuronectes planus MITCHILL 1814

(syn. P. americanus)

syn. Limandella (type-species: Pleuronectes yoko-

hamae)

Diagnosis: Thin, elongate otoliths; ventral rim

shallow, gently curving, deepest at about the

middle, dorsal rim with postdorsal angle, usual-

ly irregularly undulating, predorsal angle some-

times developed, posterior tip blunt, anterior tip

somewhat projecting like a rostrum, rounded.

Index l:h 1.65 to 1.8. Otolith size at least 6 mm.

Otoliths below 3 mm probably not diagnostically

mature.

Ostium slightly wider than cauda and much

longer. Index ol:cl 1.6 to 1.9. Ostial opening re-

duced. Cauda short, terminating at some distance

from the posterior tip of the otolith. Sulcus slightly

deepened. Colliculi separated. Circumsulcal de-

pression well developed, wide, slightly deepened.

Inner face rather flat and smooth; outer face

also flat and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

americanus 1.70-1.80 3.0 1.60 1.2-1.3 nm

yokohamae 1.65-1.80 3.0 1.70-1.90 1.0-1.2 nm

herzensteini 1.80 3.0 1.70 1.3 nm

Side dimorphism: In the case of P. americanus the

otolith from the eyed side seems to be slightly

more elongate than the one from the blind side,

but they are both rather small and probably not

fully diagnostically mature.

Discussion: Otoliths of the genus Pseudopleu-

ronectes very closely resemble those of the genus

Platichthys may be except for the somewhat less

pronounced postdorsal angle. Nevertheless,

based on otolith morphology they would proba-

bly not be regarded as representing separate gen-

era.

Species and distribution: Three species – P. ame-

ricanus from the North-West Atlantic, P. yokoham-

ae and P. herzensteini from the North-West Pacific.

Pseudopleuronectes americanus

(WALBAUM 1792)

Figs. 579-580

syn. Pleuronectes planus MITCHILL 1814

syn. Platessa pusilla DE KAY 1842

syn. Pseudopleuronectes dignabilis KENDALL 1912

Investigated otoliths: 2 otoliths (left and right)

from New Foundland, ZMH Ot. 28.1.1995.1-2 (leg.

ZMH 20103).

Discussion: The two investigated otoliths are

relatively small (about 3 mm) and probably not

fully diagnostically mature. They differ from those

of the two other species of the genus in being

more regularly rounded in outline.

Distribution: Atlantic coast of North America

from Labrador to Chesapeake Bay.

Pseudopleuronectes yokohamae

(GÜNTHER 1877)

Figs. 581-582

syn. Limanda schrencki SCHMIDT 1904

Investigated otoliths: 2 otoliths (left side) from

Hakata, Japan, ZMH Ot. 28.1.1995.3 (leg. BMNH

1923.2.26.630-32) and BMNH 1923.2.26.630-32.

Discussion: Very similar to P. herzensteini but

somewhat more elongated and with less pro-

nounced predorsal angle.

Distribution: Shores of Japan and Korea.

Pseudopleuronectes herzensteini

JORDAN & SNYDER 1901

Fig. 583

syn. Limanda angustirostris JORDAN & STARKS

1904

Investigated otoliths: 1 otolith (left side) from

Japan, BMNH 1923.2.26.636-37 (identified as

L. angustirostris)

Discussion: Very similar to P. yokohamae (see re-

spective entry).

Distribution: Japan.

238

Schwarzhans: Pleuronectiformes

576c

577

575a

575c

575b

576a

578

576b

Figs. 575-578: Kareius bicoloratus (BASILEWSKY 1855) – 10 ×

Figs. 579-580: Pseudopleuronectes americanus (WALBAUM 1792) – 10 ×

Figs. 581-582: Pseudopleuronectes yokohamae (GÜNTHER 1877) – 10 ×

Figs. 583: Pseudopleuronectes herzensteini JORDAN & SNYDER 1901 – 10 ×

581c

580

579a

579c

579b

581a

582

581b

583c

583a

583b

239

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Lepidopsetta GILL 1864

Type-species: Platichthys umbrosus GIRARD 1857

(syn. L. bilineata)

Diagnosis: Thin, moderately elongate otoliths;

ventral rim shallow, gently curving, deepest at

about the middle, dorsal rim with pre- and post-

dorsal angles, smooth, posterior tip rounded,

anterior tip somewhat projecting like a rostrum,

rounded. Index l:h 1.45 to 1.55. Otolith size at

least 5 mm. Otoliths below 3 mm not diagnosti-

cally mature.

Ostium slightly wider than cauda and much

longer. Index ol:cl 1.9 to 2.0. Ostial opening re-

duced. Cauda short, terminating at some distance

from the posterior tip of the otolith. Sulcus slight-

ly deepened. Colliculi separated. Circumsulcal

depression well developed, wide, slightly deep-

ened.

Inner face rather flat and smooth; outer face

also flat and smooth. Rims sharp.

Measurement:

l:h h:t ol:cl oh:ch con.i

bilineata 1.45-1.55 3.5 1.90-2.00 1.05-1.1 about 5

Side dimorphism: Very feeble. Otoliths of the

eyed side show a somewhat narrower sulcus and

less well separated colliculi.

Ontogeny: Smaller specimens below 3 mm

length already show rather generalized pleu-

ronectid-type otoliths and are not diagnostically

mature.

Discussion: Otoliths of the genus Lepidopsetta are

not very characteristic amongst Pleuronectinae

(sensu NORMAN, 1934). In accordance with

NORMAN they seem to be closest related to Li-

manda or Pseudopleuronectes.

Species and distribution: Two species – L. bili-

neata and L. mochigarei from the northern Pacific.

Lepidopsetta bilineata (AYRES 1854)

Figs. 584-587

syn. Platichthys umbrosus GIRARD 1857

syn. Pleuronectes perarcuatus COPE 1873

Investigated otoliths: 4 otoliths (left and right)

from California, ZMH Ot. 28.1.1995.4-7 (leg.

Fitch).

Distribution: Pacific coast of North America

from the Bering Sea to California and in the

Okhotsk Sea.

Inopsetta JORDAN 1887

Type-species: Parophrys ishyrus JORDAN & GIL-

BERT 1881

Diagnosis: Moderately thin and elongate oto-

liths; ventral rim shallow, gently curving, deep-

est at about the middle, dorsal rim with promi-

nent postdorsal and less pronounced predorsal

angle, somewhat undulating, posterior tip blunt,

undulating, anterior tip somewhat projecting like

a rostrum, rounded. Index l:h 1.60 to 1.65. Otolith

size at least 5 mm.

Figs. 584-587: Lepidopsetta bilineata (AYRES 1854) – 10 ×

586

587

584a

584c

584b

585

240

Schwarzhans: Pleuronectiformes

Ostium about as wide as cauda, but much

longer. Index ol:cl 2.0 to 2.2. Ostial opening re-

duced. Cauda short, terminating at some distance

from the posterior tip of the otolith. Cauda slightly

deepened. Colliculi separated. Circumsulcal de-

pression well developed, wide, slightly deepened.

Inner face slightly convex and rather smooth;

outer face flat and slightly ornamented. Rims

sharp.

Measurement:

l:h h:t ol:cl oh:ch con.i

ishyra 1.60-1.65 3.0 2.00-2.20 1.0 5

Side dimorphism: Very feeble. The separation

of the colliculi in otoliths of the eyed side is not

well developed.

Discussion: Otoliths of the genus Inopsetta closely

resemble those of Lepidopsetta, except for being

more elongated. Other related genera apparently

are Platichthys and Pseudopleuronectes. NORMAN

(1934) assumed that Inopsetta ishyra may prove to

be a hybrid between Lepidopsetta bilineata and

Platichthys stellatus.

Species and distribution: Inopsetta ishyra is a

monospecific genus with I. ishyra restricted to the

Puget Sound, Pacific coast of North America.

Inopsetta ishyra (JORDAN & GILBERT 1881)

Figs. 588-589

Investigated otoliths: 2 otoliths (left and right)

from the Puget Sound, ZMH Ot. 28.1.1995.8-9 (leg.

ZMH 20022).

Distribution: Puget Sound, Pacific coast of North

America.

7.7.5 Isopsetta Group

Genera: Two monospecific genera from the Pa-

cific coasts of North America – Psettichthys and

Isopsetta.

Definition and relationship: In this small and

specialized group I have placed two genera which

are characterized by the following otolith pat-

tern. The otoliths are compressed, moderately

thickset, with prominent pre- and postdorsal

angles and a reduced ostial opening. The sulcus

is shallow and very characteristic due to the ele-

vated rims of the colliculi, which are clearly sep-

arated. In general appearance, these otoliths could

even be mistaken for some kind of Soleidae. Side

dimorphism is faintly developed in the genera of

this group.

NORMAN (1934) placed these two genera at

quite different systematic positions within the

Pleuronectinae and apparently felt that they were

not particularly related to each other. Psettichthys

he related to Hippoglossoides and other large and

symmetrically mouthed genera, whereas Isopset-

ta was placed in the group of genera with small

mouths and asymmetrical jaws and dentition

(here mainly placed in the Pleuronectes-Limanda

Group). It can therefore not be excluded that the

observed similarities of the otolith morphology

represent an analogous development only.

Figs. 588-589: Inopsetta ishyra (JORDAN & GILBERT 1881) – 10 ×

588a

588c

588b

589

241

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Psettichthys GIRARD 1854

Type-species: Psettichthys melanostictus GIRARD

1854

Diagnosis: Moderately thin, rather compressed,

otoliths with almost rectangular outline; ventral

rim very shallow, gently curving, deepest at about

the middle, dorsal rim with prominent pre- and

postdorsal angles, posterior tip blunt, anterior tip

somewhat projecting like a rostrum, short and

rounded. All rims slightly undulating. Index l:h

1.4 to 1.5. Otolith size at least 5 mm.

Ostium slightly wider than cauda and much

longer. Index ol:cl 2.00. Ostial opening reduced.

Cauda short, terminating at some distance from

the posterior tip of the otolith. Sulcus shallow.

Colliculi separated, their rims somewhat elevat-

ed, the central portion somewhat deepened. Cir-

cumsulcal depression well developed, not very

wide, slightly deepened.

Inner face rather flat and smooth; outer face

also flat and slightly ornamented. Rims sharp.

Measurement:

l:h h:t ol:cl oh:ch con.i

melanostictus 1.40-1.50 3.0 2.00 1.2-1.3 nm

Side dimorphism: No data.

Discussion: According to otolith morphology

close to Isopsetta, but with somewhat less com-

pressed otoliths. NORMAN’s supposed relation

to Hippoglossoides is not confirmed by otoliths.

Species and distribution: Psettichthys is a mon-

ospecific genus with P. melanostictus restricted to

the Pacific coast of North America.

Psettichthys melanostictus GIRARD 1854

Figs. 590-591

Investigated otoliths: 2 otoliths (left side) from

off Oregon, USA, ZMH Ot. 28.1.1995.10 (leg.

BMNH 95.12.31.51-52) and BMNH 95.12.31.51-52.

Distribution: Pacific coast of North America,

from Sitka (Alaska) to Monterey (California).

Isopsetta JORDAN & GILBERT 1882

Type-species: Lepidopsetta isolepis LOCKINGTON

1880

Diagnosis: Moderately thickset, compressed,

roundish otoliths; ventral rim gently curving,

deepest at about the middle, dorsal rim with

prominent pre- and postdorsal angles, posterior

tip blunt, anterior tip slightly projecting, short

and rounded. Rims smooth to slightly undulat-

ing. Index l:h 1.1. Otolith size at least 5 mm.

Ostium slightly wider than cauda and much

longer. Index ol:cl 1.9 to 2.2. Ostial opening re-

duced. Cauda short, terminating at some distance

from the posterior tip of the otolith. Sulcus shal-

low. Colliculi separated, their rims somewhat

elevated, the central portion somewhat deepened.

Circumsulcal depression well developed, not very

wide, slightly deepened.

Inner face slightly convex and smooth; outer

face flat and rather smooth. Rims not very sharp.

Measurement:

l:h h:t ol:cl oh:ch con.i

isolepis 1.10 3.0 1.90-2.20 1.05 about 4

Figs. 590-591: Psettichthys melanostictus GIRARD 1854 – 10 ×

590a

590c

590b

591

242

Schwarzhans: Pleuronectiformes

Side dimorphism: Very feeble. Otoliths of the

eyed side show a slightly less well developed

separation of the colliculi and are also more

rounded in outline.

Discussion: Otoliths of the genus Isopsetta could

almost be mistaken for some kind of Soleidae

due to their compressed appearance and the gen-

eral habitus of the sulcus. Amongst Pleuronecti-

dae Psettichthys comes closest, but its otoliths are

less compressed.

Species and distribution: Isopsetta is a monospe-

cific genus with I. isolepis from the Pacific coast of

North America.

Isopsetta isolepis (LOCKINGTON 1881)

Figs. 592-593

Investigated otoliths: 2 otoliths (left and right)

from California, ZMH Ot. 28.1.1995.11-12 (leg.

Fitch).

Distribution: Pacific coast of North America,

from Puget Sound to southern California; fossil

from the Pleistocene of California.

7.7.6 Verasper Group

Genera: Two genera from the North-West

Pacific – Verasper and Clidoderma.

Definition and relationship: Otoliths of the fish-

es of the Verasper Group are readily recognized

by their long and wide sulcus which reaches rel-

atively close to the posterior rim of the otolith

and anteriorly shows almost no reduction of the

ostial opening. Also the cauda is comparatively

long as compared to the pleuronectid groups

described before. All these characters are distinctly

plesiomorphic for pleuronectidae and the char-

acter status thus is only comparable to that found

in the Hippoglossus Group (see respective entry).

Presumably the Verasper Group represents a very

early split-off from the main pleuronectid stem

and in turn possibly gave rise to the Microstomus-

Pleuronichthys and may be even the Samaris

Groups. In both these groups the sulcus clearly

opens anteriorly, often with a distinct excisura

and is considerably deepened.

NORMAN (1934) also did not feel too certain

about the outside relationship of these two close-

ly related genera. To Clidoderma he noted that ‘this

aberrant genus in some respects forms a connect-

ing link between the large and symmetrical-

mouthed genera and those in which the jaws and

dentition are markedly asymmetrical’. As this

concept of subdividing the Pleuronectinae may

now need to be abandoned (see general entries to

Pleuronectidae and group definitions) the gen-

era of the Verasper Group probably occupy a more

“primitive” position within the Pleuronectidae,

closer to the basal branching in this family.

Verasper JORDAN & EVERMANN 1898

Type-species: Verasper moseri JORDAN & EVER-

MANN 1898

Diagnosis: Moderately thin, not very elongate

otoliths; ventral rim very shallow, smooth, gen-

tly curving, deepest at about the middle, dorsal

rim with strong postdorsal and less well devel-

oped predorsal angles, rather smooth, posterior

Figs. 592-593: Isopsetta isolepis (LOCKINGTON 1881) – 10 ×

592a

592c

592b

593

243

Piscium Catalogus, Part Otolithi piscium, Vol. 2

tip blunt, with small notch at about the level of

the cauda, ventrally projecting strongest, anteri-

or tip somewhat projecting like a rostrum, round-

ed. Index l:h 1.45 to 1.55. Otolith size at least 6 mm.

Ostium slightly wider than cauda and not

much longer at all. Index ol:cl 1.1 to 1.4. Ostium

nearly opening anteriorly, only very slightly re-

duced. Cauda tapering, terminating not far from

the posterior tip of the otolith. Sulcus somewhat

deepened. Colliculi poorly separated. Circumsul-

cal depression well developed, moderately wide,

slightly deepened.

Inner face rather flat and relatively smooth;

outer face slightly convex and smooth. Rims

sharp.

Measurements:

l:h h:t ol:cl oh:ch con.o

variegatus 1.45-1.55 3.0 1.10-1.40 1.2-1.4 about 3

Side dimorphism: Otoliths of the eyed side are

more roundish in outline, particularly in respect

to the rostrum and the predorsal angle. At the

posterior tip of the otolith the postdorsal angle is

projecting further than the posterior-ventral por-

tion. The sulcus and in particular the ostium is

somewhat narrower.

Discussion: Otoliths of the genus Verasper very

closely resemble those of the related genus Clido-

derma, which is in full agreement with NOR-

MAN’s relating of the two genera. Otoliths of

Clidoderma are somewhat more elongate and show

a less deepened sulcus.

Species and distribution: Two species – V. moseri

and V. variegatus from Japan, the Kuril Islands

and China.

Verasper variegatus

(TEMMINCK & SCHLEGEL 1846)

Figs. 594-596

Investigated otoliths: 4 otoliths, 3 (2 left and

1 right) from Tsingtao, China, IRSNB (coll. Nolf)

and 1 (left side) from the Inland Sea of Japan,

BMNH 1905.6.6.230-1.

Distribution: Seas of southern Japan and north-

ern China.

Figs. 594-596: Verasper variegatus (TEMMINCK & SCHLEGEL 1846) – 10 ×

594a

594c

594b

595

596a

596c

596b

244

Schwarzhans: Pleuronectiformes

Clidoderma BLEEKER 1862

Type-species: Platessa asperrima TEMMINCK &

SCHLEGEL 1846

Diagnosis: Moderately thin and moderately

elongate otoliths; ventral rim very shallow,

smooth, gently curving, deepest at about the

middle, dorsal rim with moderate pre- and post-

dorsal angles, rather smooth, posterior tip blunt,

with small concavity at about the level of the

cauda, ventrally projecting strongest, anterior tip

somewhat projecting like a rostrum, rounded.

Index l:h 1.6. Otolith size at least 5 mm.

Ostium slightly wider than cauda and not

much longer at all. Index ol:cl 1.4. Ostium nearly

opening anteriorly, only very slightly reduced.

Cauda rounded, terminating not far from the

posterior tip of the otolith. Sulcus slightly deep-

ened. Colliculi poorly separated. Circumsulcal de-

pression well developed, not wide, slightly deep-

ened.

Inner face flat and relatively smooth; outer

face slightly convex and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.o

asperrimum 1.60 3.2 1.40 1.05 about 3.5

Side dimorphism: No data.

Discussion: Very close to Verasper (see respec-

tive entry).

Species and distribution: Clidoderma is a mono-

specific genus with C. asperrimum from Japan.

Clidoderma asperrimum

(TEMMINCK & SCHLEGEL 1846)

Fig. 597

Investigated otoliths: 1 otolith (left side) from

the Mutsu province, Japan, BMNH 1923.9.28.13.

Distribution: Coasts of Japan, chiefly northward;

fossil from the Upper Pliocene of Japan.

7.7.7 Microstomus-Pleuronichthys Group

Genera: Four genera from the northern Atlantic

and the northern Pacific – Microstomus, Embassich-

thys, Pleuronichthys and Hypsopsetta.

Definition and relationship: In this group I have

combined a number of genera with otoliths which

besides the Samaris Group stick out immediately

from the other Pleuronectidae. Its otoliths are

relatively small and readily recognized by the long

and deep sulcus which either reaches very close

to the anterior rim of the otoliths or even opens

to it (but different from the Samaris Group with-

out a clear excisura). Ostium and cauda are of

about equal length, although the ostium is usual-

ly slightly longer and wider. Margins and sepa-

ration of the colliculi are very feeble.

In many aspects these otoliths resemble more

certain Bothidae (like in the Bothus Group) than

Pleuronectidae. However, in this case it may not

represent a plesiomorphic character but a sec-

ondary development. I assume that this kind of

otolith morphology has developed from a char-

acter status as found in the Verasper Group, from

near which it may have originated as a special-

ized lineage. Again it documents, that NOR-

MAN’s pleuronectin grouping of genera with a

small and asymmetrical mouth is not natural (see

also general chapter to Pleuronectidae).

The four genera placed in this group could

also be seen as two sub-groups of two closely

related genera each. One of these subgroups com-

bines Pleuronichthys and Hypsopsetta, which NOR-

MAN (1934) also placed close to Verasper and

Clidoderma (see entry to Verasper Group). The oth-

er two genera – Microstomus and Embassichthys –

he related to Pseudopleuronectes and related gen-

era, placed here in the Pleuronectes-Limanda Group.

This supposed relationship clearly is not support-

ed by otolith morphology. However, the degree

Fig. 597: Clidoderma asperrima (TEMMINCK &

SCHLEGEL 1846) – 10 ×

245

Piscium Catalogus, Part Otolithi piscium, Vol. 2

of interrelationship of these two subgroups as

based on otoliths still remains somewhat ques-

tionable (hence the double name Microstomus-

Pleuronichthys Group).

Microstomus GOTTSCHE 1835

Type-species: Microstomus latidens GOTTSCHE

1835 (syn. M. kitt)

syn. Cynicoglossus BONAPARTE 1837 [1846]

(type-species: Pleuronectes microcephalus)

syn. Brachyprosopon BLEEKER 1862 (type-species:

Pleuronectes microcephalus)

syn. Veraequa JORDAN & STARKS 1904 (type-

species: V. achne)

Diagnosis: Small, compact, moderately thickset,

ovale otoliths; ventral rim very shallow, gently

curving, deepest at about the middle, dorsal rim

gently curving as well, posterior tip blunt or

rounded, anterior tip somewhat narrowing, with

very faint indication of a rostrum. All rims

smooth. Index l:h 1.40 to 1.45. Otolith size prob-

ably not exceeding 4 mm.

Ostium about as wide as cauda and not much

longer at all. Index ol:cl 1.2 to 1.4. Ostium open-

ing anteriorly or reaching very close to the anteri-

or rim of the otolith. Cauda terminating not far

from the posterior tip of the otolith. Sulcus con-

siderably deepened. Colliculi poorly defined and

separated. Circumsulcal depression faint, narrow.

Inner face rather flat and not smooth; outer

face slightly convex and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

kitt 1.40-1.45 3.0-3.5 1.20-1.40 1.0-1.15 about 8

Side dimorphism: Side dimorphism is feeble in

this genus and masked by the high degree of

variability. In otoliths of the eyed side the col-

liculi are less separated.

Variability: The variability in this genus appar-

ently is very high (refer also to figures by

CHAINE, 1936) and concerns mainly the outline

of the otoliths. Although I have investigated only

otoliths of one recent species (M. kitt) it seems

that the species will not be easily distinguished

by means of otoliths judging from the low level

of diagnostic features and the high level of vari-

ability.

Discussion: Otoliths of the genus Microstomus

in many aspects resemble those of the genera

Pleuronichthys and Hypsopsetta, but are more com-

pressed and easily characterized by the anterior-

ly narrowing outline.

Species and distribution: Four species – M. kitt

from the North-East Atlantic and M. achne,

M. shuntovi and M. pacificus from the northern Pa-

cific (the latter also as fossil from the Pleistocene

of California).

Microstomus kitt (WALBAUM 1792)

Figs. 598-601

syn. Pleuronectes microcephalus DONOVAN 1803

syn. Pleuronectes laevis SHAW 1803

syn. Pleuronectes quenselii HOLLBERG 1821

syn. Pleuronectes quadridens FABRICIUS 1828

syn. Pleuronectes microstomus FABER 1828

syn. Platessa pola CUVIER 1829

syn. Microstomus groenlandicus REINHARDT

1839

syn. Pleuronectes gilli STEINDACHNER 1868

Investigated otoliths: 5 otoliths (2 left and 3 right)

from the North Sea, ZMH Ot. 29.1.1995.1-5 (coll.

Schwarzhans).

Distribution: Coasts of north-western Europe,

from the White Sea to the Bay of Biscay and to

Iceland.

Embassichthys JORDAN & EVERMANN 1896

Type-species: Cynicoglossus bathybius GILBERT

1891

Remarks: Embassichthys is a monospecific genus

with E. bathybius known from the deeper waters

off the Pacific coast of North America and Japan.

Otoliths have not been available for investiga-

tion. According to NORMAN (1934) Embassich-

thys is closely related to Microstomus.

Pleuronichthys GIRARD 1856

Type-species: Pleuronichthys coenosus GIRARD

1856

syn. Heteroprosopon BLEEKER 1862 (type-species:

Platessa cornuta)

246

Schwarzhans: Pleuronectiformes

Diagnosis: Moderately thin, elongate otoliths;

ventral and dorsal rim very shallow, gently curv-

ing, deepest at about their respective middle,

dorsal rim with feeble postdorsal and broad pre-

dorsal angle, posterior tip blunt, usually ventral-

ly projecting, anterior tip somewhat projecting

like a rostrum, rounded or somewhat pointed.

Rims usually smooth. Index l:h 1.7 to 1.95. Oto-

lith size not exceeding 6 mm. Otoliths smaller than

3.5 to 4 mm probably not fully diagnostically

mature.

Ostium slightly wider than cauda and not

much longer. Index ol:cl variable, 1.2 to 2.0. Os-

tium nearly opening anteriorly, only very slight-

ly reduced. Cauda terminating not very far from

the posterior tip of the otolith. Sulcus markedly

deepened. Colliculi poorly defined and separat-

ed. Circumsulcal depression well developed,

narrow, slightly deepened.

Inner face rather flat, not smooth; outer face

slightly convex or flat and smooth. Rims moder-

ately sharp to sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

coenosus 1.75-1.95 2.5-3.3 1.5-2.0 1.0-1.1 5-6

decurrens 1.75-1.80 3.2 1.7-2.0 1.0-1.1 about 8

verticalis 1.70-1.95 3.0 1.5-2.0 1.0-1.1 about 6

ritteri 1.80-1.90 2.4-3.2 1.5-1.7 1.3-1.5 7-8

Side dimorphism: Side dimorphism in the oto-

liths of this genus is very inconspicuous or else

masked by the high degree of variability. In some

species otoliths of the eyed side show a less pro-

nounced posterior-ventral projection.

Ontogeny and variability: Otoliths smaller than

3.5 to 4 mm are usually thinner than the larger

ones and less ornamented.

Variability of the otoliths of Pleuronichthys is

considerable and affects outline as well as pro-

portions of sulcus and otolith. In fact, differenti-

ation of the various species by means of otoliths

alone may not always be possible due to overlap

in characteristics caused by this high degree of

intraspecific variations.

Discussion: Pleuronichthys apparently is closely

related to Hypsopsetta. Micromesistius is also sim-

ilar but its otoliths are more compressed. All three

genera share the long and deep sulcus, opening

(or nearly opening) to the anterior rim.

Species and distribution: Seven species – P. cor-

nutus from the North-West Pacific (also as fossil

from the Pliocene of Japan) and P. coenosus, P. de-

currens, P. nephelus, P. ocellatus, P. ritteri and P. ver-

ticalis from the Pacific coast of North America.

Pleuronichthys coenosus GIRARD 1856

Figs. 602-605

Investigated otoliths: 4 otoliths (left and right)

from California, ZMH Ot. 29.1.1995.6-9 (leg.

Fitch).

Discussion: P. coenosus is hardly distinguishable

from P. decurrens and P. verticalis. Its otoliths are

usually somewhat more elongate than those of

P. decurrens and, at least in large specimens, more

thickset than those of P. verticalis.

Distribution: Coast of California.

Figs. 598-601: Microstomus kitt (WALBAUM 1792) – 10 ×

600a

600c

600b

599

601

598

247

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Pleuronichthys decurrens

JORDAN & GILBERT 1881

Figs. 606-609

syn. Pleuronichthys quadrituberculatus JORDAN &

GILBERT 1881

Investigated otoliths: 4 otoliths (left and right)

from California, ZMH Ot. 29.1.1995.10-13 (leg.

Fitch).

Discussion: Very similar to P. coenosus and

P. verticalis but usually somewhat more com-

pressed and with a less pronounced postdorsal

projection. Rostrum very short.

Distribution: Pacific coast of North America,

from Alaska to California.

Figs. 602-605: Pleuronichthys coenosus GIRARD 1856 – 10 ×

Figs. 606-609: Pleuronichthys decurrens JORDAN & GILBERT 1881 – 10 ×

602a

602c

607

603

605

602b

604a

606c

604b

606a

608

606b

609

248

Schwarzhans: Pleuronectiformes

Pleuronichthys verticalis

JORDAN & GILBERT 1881

Figs. 610-617

Investigated otoliths: 8 otoliths (left and right)

from California, ZMH Ot. 29.1.1995.14-21 (leg.

Fitch).

Discussion: Very similar to P. coenosus but usu-

ally with a more pronounced postdorsal projec-

tion and also somewhat thinner.

Distribution: California and Gulf of California.

Pleuronichthys ritteri

STARKS & MORRIS 1907

Figs. 618-621

Investigated otoliths: 4 otoliths (left and right)

from California, ZMH Ot. 29.1.1995.22-25 (leg.

Fitch).

Discussion: Otoliths of P. ritteri may be recog-

nized by their widened ostium (see index oh:ch)

distinguishing it from the other three species in-

vestigated.

Distribution: California, also fossil from the

Pleistocene.

Hypsopsetta GILL 1863

Type-species: Pleuronichthys guttulatus GIRARD

1857

Diagnosis: Rather thickset, Moderately elongate

otoliths; ventral rim gently curving, deepest

slightly anterior of the middle, dorsal rim with

pronounced postdorsal and less pronounced pre-

dorsal angle, otherwise straight, posterior tip

blunt, nearly vertically cut, anterior tip somewhat

projecting like a rostrum, broadly rounded. Rims

smooth or irregularly undulating. Index l:h 1.5 to

1.75. Otolith size not exceeding 5 to 6 mm.

Ostium markedly wider than cauda and long-

er. Index ol:cl 1.6 to 2.0. Ostium nearly opening

Figs. 610-617: Pleuronichthys verticalis JORDAN & GILBERT 1881 – 10 ×

610a

610c

617

611

612

610b

613

616

614

615

249

Piscium Catalogus, Part Otolithi piscium, Vol. 2

anteriorly, only very slightly reduced. Cauda ter-

minating not very far from the posterior tip of

the otolith. Sulcus markedly deepened. Colliculi

poorly defined and separated. Circumsulcal de-

pression well developed, narrow, slightly deep-

ened.

Inner face rather flat, not smooth; outer face

flat and rather smooth. Rims not very sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

guttulatus (left) 1.70-1.75 2.6 1.60-1.75 1.2-1.4 3.5

guttulatus (right) 1.50-1.55 2.6 1.85-2.00 1.3 3.5

Side dimorphism: Quite markedly. Otoliths of

the eyed side are more compressed due to a more

deeply curving ventral rim. Also the postdorsal

angle is somewhat projecting and the index ol:cl

is somewhat higher.

Discussion: Otoliths of the genus Hypsopsetta are

very similar to those of Pleuronichthys but some-

what more compressed and with a different de-

velopment of the posterior rim.

Species and distribution: Two species from the

Pacific coast of North America – H. guttulata and

H. macrocephala.

Hypsopsetta guttulata (GIRARD 1857)

Figs. 622-625

syn. Parophrys ayresii GÜNTHER 1862

Investigated otoliths: 4 otoliths (left and right)

from California, ZMH Ot. 29.1.1995.26-29 (leg.

Fitch).

Distribution: California.

Rhombosoleinae

7.7.8 Pelotretis Group

Genera: A single monospecific genus – Pelotretis –

endemic to New Zealand.

Definition and relationship: The elongate and

thin otoliths of the genus Pelotretis could go as a

Bothidae as well as a Pleuronectidae. The long

and distinctly inframedian rostrum, the only very

slightly reduced ostial opening and the long sul-

cus reaching relatively close to the posterior tip

of the otolith all resemble otoliths of certain both-

id genera (Paralichthys Group) and even Lepi-

dorhombus of the Scophthalmidae.

The genus Pelotretis is one of those enigmatic

right eyed flatfishes of the southern Australian

and New Zealandian region that NORMAN

(1934) had combined in the subfamily Rhombos-

oleinae. The Rhombosoleinae are here regarded

Figs. 618-621: Pleuronichthys ritteri STARKS & MORRIS 1907 – 10 ×

618a

618c

620a

618b

619

621

620b

250

Schwarzhans: Pleuronectiformes

as a polyphyletic group and its members have

been re-arranged in groups partly outside the

Pleuronectidae (see chapter 5.3.2. and introduc-

tion to Pleuronectidae). Pelotretis tentatively is left

with the Pleuronectidae, but its relationship re-

mains unclear as from otolith morphology. How-

ever, it may possibly be related to the genus Rhom-

bosolea (Rhombosolea Group), and together with it

is tentatively left in the much reduced subfamily

Rhombosoleinae.

Pelotretis WAITE 1911

Type-species: Pelotretis flavilatus WAITE 1911

Diagnosis: Thin, elongate otoliths; ventral rim

very shallow, dorsal likewise shallow, shorter,

without prominent angles, posterior tip irregu-

larly rounded or inframedianly pointed, anteri-

orly a long and inframedian, thereby massive and

often pointed rostrum. Index l:h 1.7 to 1.85. Oto-

lith size up to about 6 mm.

Ostium slightly wider than cauda and much

longer. Index ol:cl 2.0 to 2.6. Ostium anteriorly

open, just very slightly reduced. Cauda short,

terminating not far from the posterior tip of the

otolith. Sulcus rather shallow. Colliculi separat-

ed. Circumsulcal depression well developed,

moderately wide, slightly deepened.

Inner face rather flat and smooth; outer face

also flat and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

flavilatus 1.70-1.85 3.2-3.8 2.00-2.60 1.1-1.2 about 8

Side dimorphism: Affecting many characters,

but in total rather moderate. Otoliths of the eyed

side show less well separated colliculi, a more

rounded posterior-dorsal portion of the rim and

sometimes a faint excisura. Also the circumsulcal

depression is better developed around the poste-

rior tip of the cauda and often ornamented with

delicate radial furrows. Finally, the inner face of

right (eyed) side otoliths is just slightly more

convex.

Variability: Moderate, restricted to few details

of the outline and the sulcus proportions.

Discussion: See entry to group.

Species and distribution: Pelotretis is a mono-

specific genus with P. flavilatus endemic to New

Zealand.

Figs. 622-625: Hypsopsetta guttulata (GIRARD 1857) – 10 ×

622a

622c

623a

622b

625

624

623b

251

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Pelotretis flavilatus WAITE 1911

Figs. 626-630

Investigated otoliths: 6 otoliths, 4 (left and right,

figs.) from New Zealand, AIM 2759 (coll. Gren-

fell), 2 (left and right) from off Wellington, New

Zealand, BMNH 1935.3.14.216.

Distribution: Shores of New Zealand and Chat-

ham Islands.

Remarks: A potential fossil representative of Pelo-

tretis is figured for further comparison (fig. 631;

Pelotretis sp. from the Lower Pliocene, Wanganu-

ian, of Martinborough, New Zealand, coll. Pfeil,

BSP). This otolith probably represents a subadult

with a not fully mature morphology.

7.7.9 Rhombosolea Group

Genera: A single genus – Rhombosolea – from the

coasts of southern Australia and New Zealand.

Definition and relationship: Otoliths of Rhom-

bosolea again are rather typical pleuronectids, not

much unlike those found in the Pleuronectes-

Limanda Group. Characteristic is the not much

reduced ostial opening and the ventral and dor-

sal portions of the inner face, which are strongly

bent outward.

Rhombosolea is the one genus of NORMAN’s

Rhombosoleinae which remains at its position

relative to the Pleuronectidae (see also chapter

5.2.3 and introduction to Pleuronectidae). Of the

other “former” Rhombosoleinae only the genus

Pelotretis (Pelotretis Group) may possibly be relat-

ed and is kept in that subfamily.

Rhombosolea GÜNTHER 1862

Type-species: Rhombosolea monopus GÜNTHER

1862 (syn. R. plebeia)

syn. Bowenia HAAST 1873 (type-species:

B. novaezeelandiae, syn. R. plebeia)

syn. Apsetta KYLE 1900 (type-species: A. thomp-

soni, syn. R. plebeia)

syn. Adamasoma WHITLEY & PHILLIPS 1939

(type-species: Rhombosolea retiaria)

Diagnosis: Rather thin, moderately elongate oto-

liths; ventral and dorsal rims gently and regular-

ly curving, but often intensely ornamented, some-

times with tendency to fenestrate development,

posterior tip usually rounded, anterior tip blunt

or with somewhat projecting rostrum. Index l:h

1.35 to 1.60. Otolith size up to 8 mm. Otoliths

below 4 to 4.5 mm representing a quite distinct

ontogenetic stage (see below).

Ostium slightly wider than cauda and longer.

Index ol:cl 1.45 to 2.25. Ostial opening only slightly

reduced. Cauda moderately short, terminating

not very far from the posterior tip of the otolith.

Sulcus slightly deepened. Colliculi not very well

separated. Circumsulcal depression well devel-

oped, wide, moderately deepened.

Inner face almost flat in the horizontal direc-

tion, but rather strongly convex in the vertical

direction due to the marginal portions of the

ventral and sometimes also dorsal field being

bend outward; outer face concave, rarely flat,

usually intensely ornamented. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

plebeia (adult) 1.45-1.50 3.0 1.60-1.70 1.2-1.3 about 6

plebeia (juv., left) 1.35 4.0 1.90 1.25 nm

plebeia (juv., right) 1.40 4.0 1.70 1.05 nm

leporina (ad.,left) 1.45-1.55 3.5 1.8-1.9 1.2-1.3 about 5

leporina (ad., right) 1.65 4.0 1.60 1.5 about 6

tapirina (ad., left) 1.45-1.50 4.0 2.20-2.25 1.4-1.5 about 5

tapirina (ad., right) 1.60-1.65 4.0 1.60 1.2-1.3 about 5

tapirina (juv., left) 1.45 3.0 (3.3) 1.1 about 7

tapirina (juv., right) 1.40 3.0 1.60 1.3 about 10

retiaria 1.50 3.5 1.80 1.15 about 4

Side dimorphism: Rhombosolea no doubt is one

of the genera with more remarkable side dimor-

phism in otoliths. Furthermore, side dimorphism

in Rhombosolea is special in two aspects – first,

unlike in most flatfishes it is the otolith of the

blind side which departs from the “normal”

morphology in most aspects, and secondly side

dimorphism of subadults is distinctively differ-

ent from that of adults (see also chapters 6.3 and

6.5; figs. 632-635, 638-643). This has best been

studied with otoliths of the species R. tapirina.

In adults otoliths of the blind (left) side (larg-

er than 4 to 4.5 mm) are more compressed, show

a tendency to develop a thin, deep excisura, show

less well separated colliculi, a higher index ol:cl,

and sometimes a lesser index oh:ch.

In smaller otoliths (less than 4 to 4.5 mm) those

of the blind (left) side may show a rostrum and

a clear ostial opening, which those of the right

side may not show. The index ol:cl is higher and

the index oh:ch lesser in otoliths of the blind side.

252

Schwarzhans: Pleuronectiformes

Otoliths of the eyed side show a more flat inner

face.

Ontogeny and variability: Apart from the

change in quality of the side dimorphism there

are some other prominent ontogenetic changes

in otolith morphology as well. Smaller otoliths

(less than 4 to 4.5 mm) have less ornamented

margins, sometimes a well developed postdorsal

angle and the inner face is much less convex in

the vertical direction (i.e. the dorsal and ventral

fields are not as yet bend outward). Also, these

otoliths often show a clear rostrum (at least those

of the left, blind side), which is unknown from

adults (except for the species R. retiaria). (See also

chapter 6.3)

In the light of all these morphological chang-

es it comes as a relief that at least the variability

is not extraordinary. Variations are mainly restrict-

ed to the irregularly ornamented outline of the

otoliths.

Discussion: See entry to group.

Species and distribution: Four species from the

temperate seas of Australia and New Zealand –

R. plebeia, R. leporina, R. tapirina and R. retiaria.

Figs. 626-630: Pelotretis flavilatus WAITE 1911 – 10 ×

Fig. 631: Pelotretis sp. – 10 ×

626a

626b

627a

628

629

630

627b

631a

631b

253

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Rhombosolea plebeia (RICHARDSON 1843)

Figs. 632-635

syn. Rhombosolea monopus GÜNTHER 1862

syn. Bowenia novaezeelandiae HAAST 1873

syn. Apsetta thompsoni KYLE 1900

Investigated otoliths: 4 otoliths from New Zea-

land, 1 (adult right, fig. 632) ZMH Ot. 31.1.1995.1

(leg. ZMH 20106), 1 (adult right, fig. 633) AUG-V

289 (coll. Grenfell), 2 (subadult left and right, figs.

634-635) AIM 2761 (coll. Grenfell).

Discussion: Otoliths of the three species R. ple-

beia, R. leporina and R. tapirina are all very similar

to each other. May be those of R. plebeia are the

most compressed of these.

Distribution: New Zealand and Auckland Is-

lands, records from Australia doubtful as to

NORMAN (1934).

Rhombosolea leporina GÜNTHER 1862

Figs. 636-637

syn. Rhombosolea millari WAITE 1911

Investigated otoliths: 3 otoliths from New Zea-

land, 2 (left) AUG-V 289 (coll. Grenfell), 1 (right)

BMNH 73.12.13.71-3.

Discussion: Very similar to R. tapirina. If there is

any discernable difference between the otoliths

of the two species it is that those of R. leporina

show a more regular outline with a much smooth-

er dorsal rim. In left hand otoliths the ostium is

rather narrow as compared to R. tapirina.

Distribution: Australia and New Zealand.

Rhombosolea tapirina GÜNTHER 1862

Figs. 638-643, 21, 26

syn. Rhombosolea flesoides GÜNTHER 1863

syn. Pleuronectes victoriae CASTELNAU 1872

Investigated otoliths: 8 otoliths, 4 (adult left and

right, figs. 638-641) from New Zealand, AIM 2762

(coll. Grenfell), 2 (subadult left and right, figs.

642-643) from Port Philipp, Australia, ZMH Ot.

31.1.1995.2-3 (leg. ZMH 20107), and 2 (adult re-

versed left and right, figs. 26) from Dunedin, New

Zealand, BMNH 76.3.25.1.

Discussion: Very similar to R. leporina (see re-

spective entry).

Otoliths of this species have been used to

analyze side dimorphism occurring in this genus

as well as ontogenetic changes and the combined

effects of the two (see entry to genus).

Finally, a representative of this species was

selected to analyze effects of reversal on otolith

morphology. The otoliths of the reversed speci-

men were found to be completely out of bounds,

showing very little resemblance to otoliths of

“normal” non-reversed specimens (see chapter

6.4 for detailed discussion).

Distribution: Southern temperate Australia,

New Zealand, Auckland and Campbell Islands.

Rhombosolea retiaria HUTTON 1873

Fig. 644

Investigated otoliths: 1 otolith (left) from New

Zealand, BMNH 1935.3.14.227.

Discussion: Easily recognized by its smooth and

gently curving dorsal rim and the rather massive

and long rostrum. This the only species of Rhom-

bosolea in which otoliths from adults show a dis-

tinct rostrum.

Distribution:

New Zealand, entering fresh water.

Samarinae

7.7.10 Samaris Group

Genera: This group combines three genera of

NORMAN’s Samarinae – Samaris, Samariscus and

Plagiopsetta – plus a fourth genus from his Rhom-

bosoleinae – Azygopus. Geographical distribution

is chiefly the tropical and subtropical Indo-Pacif-

ic, with the exception of Azygopus which is re-

stricted to temperate Australia and New Zealand.

Definition and relationship: The fishes of the

genera placed in the Samaris Group show a

number of unique specializations (except for

Azygopus, which is placed here mainly because of

similarity in otolith morphology). According to

254

Schwarzhans: Pleuronectiformes

NORMAN (1934) these are the expanded hypoc-

oracoids, the loss of the pectoral fins on the blind

side and the reduced number of 4 rays of the

pectoral fin on the eyed side (except for Plagio-

psetta). Several species are specially adapted to

living in a reefoidal environment. In recent liter-

ature the fishes of this group are placed in a fam-

ily of its own – Samaridae (CHAPLEAU 1993 and

NELSON 1994) – but are kept here in subfamily

ranking provisionally until the interrelationship

Figs. 632-635: Rhombosolea plebeia (RICHARDSON 1843) – 10 ×

Figs. 636-637: Rhombosolea leparina GÜNTHER 1862 – 10 ×

632a

632b

632c

634a

635a

636a

633

635b

634b

636b

637

255

Piscium Catalogus, Part Otolithi piscium, Vol. 2

638a

638b

638c

642a

643a

639a

640

643b

639b

642b

641

639c

Figs. 638-643: Rhombosolea tapirina GÜNTHER 1862 – 10 ×

256

Schwarzhans: Pleuronectiformes

of the Pleuronectidae s.l. becomes further re-

vealed.

The otoliths of this group likewise are quite

specialized. They are relatively small and thick-

set and show an extremely deepened sulcus with

a clear ostial opening often associated with an

excisura. Amongst Pleuronectiformes these are

the otoliths with the deepest, v-shaped sulcus.

Outline and separation of colliculi often is barely

visible. They are still recognizable as pleuronec-

tiform otoliths by the well developed and often

very deep circumsulcal depression. This charac-

ter also holds against them representing a plesi-

omorphic otolith morphology which might be

suggested by the other features. In fact, the deep

sulcus and the clear ostial opening may very well

be a secondary specialized development which

could have evolved from similar morphologies

as found in the Verasper and the Microstomus-Pleu-

ronichthys Groups.

It must be noted that at least the species of the

genera Plagiopsetta and Samaris contain two dis-

tinct morphologies which in the following text

will be termed morphology A and B. Whether

Samariscus and Azygopus show a similar phenom-

enon is not as yet known. Also it is not yet known

what may be the cause for the presence of these

two distinct morphologies. Recently, a similar

phenomenon has been reported from certain ophi-

diiform genera, where it correlates with sexual

dimorphism (SCHWARZHANS, 1994). So far, sex-

ual dimorphism in otoliths is extremely rare. Al-

though fishes of the order Pleuronectiformes ex-

hibit a wide spectrum of sexual dimorphism both

in character an intensity, there is no proof so far

that this finds its reflection in otolith morpholo-

gy as well (for further discussion see also chap-

ter 6.5).

Plagiopsetta FRANZ 1910

Type-species: Plagiopsetta glossa FRANZ 1910

Diagnosis: Small, thickset, elongate otoliths;

ventral and dorsal rim very shallow, gently curv-

ing, dorsal rim without conspicuous angles, pos-

terior tip pointed, usually ventrally projecting,

anterior tip rather blunt, with a short, massive

rostrum and a distinct excisura. Index l:h 1.45 to

2.00. Otolith size not exceeding 3 mm at most.

Ostium slightly wider than cauda and not

much longer. Differentiation of ostium and cau-

da very feeble due to poor definition of outline of

colliculi. Sulcus very deep, v-shaped. Ostium

clearly opening anteriorly; excisura present. Cau-

da terminating at moderate distance from the

posterior tip of the otolith. Circumsulcal depres-

sion well developed, narrow, rather deep.

Inner face rather flat to slightly convex, not

smooth; outer face slightly convex or flat and

smooth. Rims smooth and thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

glossa (A, left) 1.50 1.8 about 1.7 1.2 about 3

glossa (A, right) 1.45 2.8 about 2.0 1.1 about 3

glossa (B, left) 1.70 1.9 about 1.4 1.0 about 5

glossa (B, right) 2.00 2.8 about 1.8 1.3 about 5

Side dimorphism: Otoliths of the eyed side are

consistently much more thin than those of the

blind side. Minor differences may also exist in

other otolith and sulcus proportions.

Morphology types: The two morphology types

found in Plagiopsetta certainly would have been

attributed to separate species when studied with

isolated otoliths alone.

Fig. 644: Rhombosolea retiaria HUTTON 1873 – 10 ×

257

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Morphology A (figs. 645-646) shows rather

compressed otoliths with a comparatively short

sulcus and a more strongly convex inner face.

Morphology B (figs. 647-648) contains much

more elongate otoliths with perfectly smooth rims

and a more flat inner face.

Discussion: Otoliths of the genus Plagiopsetta

closely resemble those of the related genera Sa-

maris and Samariscus.

Species and distribution: Plagiopsetta glossa is a

monospecific genus with P. glossa restricted to the

waters around Japan.

Plagiopsetta glossa FRANZ 1910

Figs. 645-648

Investigated otoliths: 4 otoliths (left and right)

from off Kochi, Japan, ZMH Ot. 29.1.1995.30-33

(leg. Sasaki; fishes now in BMNH coll.).

Distribution: Japan.

Samaris GRAY 1831

Type-species: Samaris cristatus GRAY 1831

Diagnosis: Small, thickset, elongate otoliths;

ventral and dorsal rim very shallow, gently curv-

ing, dorsal rim sometimes with postdorsal angle

and predorsal projection, posterior tip rounded

Figs. 645-648: Plagiopsetta glossa FRANZ 1910; figs. 645-646 morphotype A, figs. 647-648 morphotype B – 25 ×

645a

645b

646a

647a

646b

647b

647c

645c

648a

648b

258

Schwarzhans: Pleuronectiformes

or blunt, anterior tip rather blunt, with a short,

massive, sometimes pointed rostrum and usual-

ly distinct excisura. Index l:h 1.55 to 1.65. Otolith

size not exceeding 3 mm at most.

Ostium slightly wider than cauda and not

much longer. Differentiation of ostium and cau-

da very feeble due to poor definition of outline of

colliculi. Sulcus very deep, v-shaped. Ostium

clearly opening anteriorly; excisura present. Cau-

da terminating at moderate distance from the

posterior tip of the otolith. Circumsulcal depres-

sion well developed, narrow, very deep.

Inner face slightly convex, not smooth; outer

face slightly convex or flat and rather smooth.

Rims smooth or slightly undulating, thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

cristatus (A, left) 1.55 2.1 about 1.4 1.0 2.5

cristatus (A, right) 1.65 2.4 about 1.6 1.0 3.0

cristatus (B, left) 1.60 1.8 about 1.5 1.1 2.8

cristatus (B, right) 1.60 2.2 about 1.5 1.1 3.0

†validus 1.70 2.0 about 1.8 1.1 2.5

Side dimorphism: Less well developed than in

the genus Plagiopsetta. Still otoliths from the eyed

side are slightly thinner and their inner face slight-

ly more convex than those of the blind side.

Morphology types: The two morphology types

found in Samaris certainly would have been at-

tributed to separate species when studied with

isolated otoliths alone.

Morphology A (figs. 649-650) shows otoliths

with a flat, horizontal dorsal rim, a pronounced

postdorsal angle, a blunt posterior tip and a rath-

er distinct and pointed rostrum.

Morphology B (figs. 651-652) is characterized

by more ovally shaped otoliths with a gently

curving dorsal rim including a broad predorsal

projection and a rounded posterior tip. Also the

rostrum is shorter and blunt or rounded.

Discussion: Otoliths of the genus Samaris close-

ly resemble those of the related genera Plagiopset-

ta and Samariscus. Those of Samaris are the largest

in size and with a rather characteristic outline in

morpho-type A.

Species and distribution: According to HEEM-

STRA ( 1986) probably a monospecific genus (also

indicated by NORMAN, 1934, who noted 5 nom-

inal species) with S. cristatus widely distributed

in the Indo-Pacific. In a recent publication by

QUERO, HENSLEY & MAUGE (1989), however,

two additional species are listed – S. macrolepis

and S. costae. In addition the fossil species

S. validus is here described from the Lower

Pliocene of New Zealand.

Samaris cristatus GRAY 1831

Figs. 649-652

?syn. Arnoglossus cacatuae OGILBY 1910

syn. Samaris ornatus VON BONDE 1922

syn. Samaris delagoensis VON BONDE 1925

?syn. Samaris macrolepis NORMAN 1927

Investigated otoliths: 8 otoliths, 6 (left and right)

from Hongkong, IRSNB (coll. Nolf, leg. Stinton),

1 (right side) from the Java Sea, BMNH

1931.4.23.28, 1 (left side) from Hinan, China, SMF.

Distribution: From South Africa throughout the

Indian Ocean, to the Chinese seas, Japan, Indo-

nesia and Queensland.

Samaris validus n.sp.

Fig. 653

Name: validus (lat.) = valid, referring to first fossil

record of this group.

Holotype (and unique specimen): Fig. 653, BSP

1984 X 116.

Type locality: Martinborough, New Zealand

northern Island.

Age: Wanganuian, Lower Pliocene.

Diagnosis: Moderately elongate, thickset otoliths

with flat dorsal and ventral rims and prominent

rostrum. Sulcus deep, anteriorly opening, with

distinct excisura. Circumsulcal depression well

developed, rather wide and deep.

Description: Outline: Otolith about 3.5 mm long,

almost rectangular in outline except for the strong-

ly protruding rostrum. Ventral and dorsal rims

flat, practically horizontal and parallel, posterior

rim vertically cut. Excisura broad and deep, anti-

rostrum small. Index l:h 1.7.

Inner face: Moderately convex, not smooth.

Sulcus long, deep, moderately wide, anteriorly

open. Colliculi indistinct, ostium somewhat long-

er than cauda. Circumsulcal depression well de-

veloped, wide and rather deep.

259

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Other views: Otolith compact and thickset,

with smooth and not very sharp rims. Outer face

rather flat and smooth.

Discussion: This otolith is slightly larger than

those of the recent S. cristatus, possibly indicat-

ing that the fossil species was growing to larger

sizes than the recent one. Although in general

very similar to S. cristatus, S. validus differs in the

nearly straight ventral rim and the long and

massive rostrum. It probably represents morpho-

type A. The unique holotype is very well pre-

served and represents the first record of the ge-

nus from New Zealand.

Figs. 649-652: Samaris cristatus GRAY 1831; figs. 649-650 morphotype A, figs. 651-652 morphotype B – 15 ×

Fig. 653: Samaris verus n.sp. – 15 ×

649a

650b

650a

651a

649b

653b

651c

649c

652a

653c

653a

652b

649b

653e

653d

260

Schwarzhans: Pleuronectiformes

Samariscus GILBERT 1905

Type-species: Samariscus corallinus GILBERT 1905

Diagnosis: Small, thickset, moderately elongate

otoliths; ventral and dorsal rims gently curving,

smooth or undulating, posterior tip pointed or

rounded, anterior tip rather blunt, with a short,

massive rostrum and a more or less distinct ex-

cisura. Index l:h 1.25 to 1.75. Otolith size not ex-

ceeding 2.5 mm at most. Otoliths smaller than 1

to 1.5 mm probably not diagnostically mature.

Ostium slightly wider than cauda and not

much longer. Differentiation of ostium and cau-

da very feeble due to poor definition of outline of

colliculi. Sulcus very deep, v-shaped. Ostium

clearly opening anteriorly; excisura present. Cau-

da terminating at moderate distance from the

posterior tip of the otolith. Circumsulcal depres-

sion well developed, narrow, rather deep to very

deep.

Inner face flat to slightly convex, not smooth;

outer face slightly to strongly convex and smooth.

Rims thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

japonicus 1.30-1.50 2.5-3.0 1.5-2.0 1.0-1.2 about 4

sunieri 1.40 2.5 1.6 1.2 about 4

huysmani 1.75 1.5 about 1.5 nm about 4

triocellatus 1.25-1.30 2.2 about 2.0 1.0 about 5

Side dimorphism: Judging from the otoliths of

S. japonicus the degree of side dimorphism is

moderate. Otoliths of the eyed side are more reg-

ularly rounded in outline, slightly more thin with

a slightly more convex inner face, and also the

excisura is usually deeper.

Ontogeny and variability: The otoliths of S. trio-

cellatus are less than 1 mm long and were obtained

from a very small fish. They are probably sub-

adult and in many ways are quite generalized in

appearance. Sulcus and circumsulcal area are not

very deep as yet. Its low index l:h may also reflect

an early ontogenetic stage. Otherwise the otolith

is relatively thickset.

A series of otoliths obtained from S. japonicus

exhibit a moderate degree of variability, mainly

restricted to details of the outline, particularly

concerning the expression of the dorsal rim and

the rostrum.

Morphology types: The only species of which a

larger series of otoliths is available is S. japonicus.

There, no distinction in two otolith morpho-types

can be observed as this is the case in Samaris and

Plagiopsetta. However, this could still be purely

accidental.

Discussion: Closely related to Samaris and Pla-

giopsetta (see respective entries).

Species and distribution: About 17 species (ac-

cording to QUERO; HENSLEY & MAUGE, 1989)

from the tropical and subtropical waters of the

Indo-West-Pacific – S. asanoi, S. corallinus, S. de-

soutterae, S. fasciatus, S. filipectoralis, S. huysmani,

S. inornatus, S. japonicus, S. latus, S. longimanus,

S. luzonensis, S. macrognathus, S. maculatus,

S. nielseni, S. sunieri, S. triocellatus and S. xeni-

cus. Habitat of these fishes is often associated with

reefs or near reef environments, which is rather

untypical for Pleuronectiform fishes.

Samariscus japonicus KAMOHARA 1936

Figs. 654-659

Investigated otoliths: 8 otoliths (left and right)

from off Kochi, Japan, ZMH Ot. 29.1.1995.34-41

(leg. Sasaki).

Discussion: Similar to S. sunieri, but otoliths of

that species have a shallower dorsal rim and a

deeper ventral rim (although resulting index l:h

is the same).

Distribution: Chiefly off Japan.

Samariscus sunieri

WEBER & BEAUFORT 1929

Fig. 660

Investigated otoliths: 1 otolith (left side) from

St. Nikolaas Bay, Bali, BMNH 1933.2.18.17 (para-

type).

Discussion: Similar to S. japonicus (see respec-

tive entry).

Distribution: Chiefly around Bali, Indonesia.

261

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Samariscus huysmani WEBER 1913

Fig. 661

Investigated otoliths: 1 otolith (left side) from

Indonesia, 08°50’S/114°14’E, BMNH 1984.1.1.108.

Discussion: This otolith is readily recognized by

its smooth and gently and regularly curving dor-

sal and ventral rims, the symmetrically pointed

posterior and anterior (rostrum) tips, and the very

thickset appearance. If Samariscus species also

include two morphotypes as observed in Samaris

and Plagiopsetta this otolith would become the

only candidate for a morpho-type B of all the

Samariscus otoliths investigated.

Distribution: Gulf of Martaban and Java Sea.

Samariscus triocellatus WOODS 1984

Figs. 662-663

Investigated otoliths: 2 otoliths (left and right)

from the Eniwetok atoll, Marshall Islands, SMF

20184.

Discussion: These otoliths are very small (about

0.6 mm long) and originate from a small and

possibly subadult fish. They are certainly not

diagnostically mature. Larger specimens have

been recently figured by SMALE et al. (1995). They

are also compressed, resembling in proportions

those of S. japonicus but show a rather narrow

sulcus and a very sharpely pointed rostrum.

Distribution: Marshall Islands, Micronesia.

Figs. 654-659: Samariscus japonicus KAMOHARA 1936 – 25 ×

654a

655b

655a

658

654b

655c

654c

659

657

656

262

Schwarzhans: Pleuronectiformes

Azygopus NORMAN 1926

Type-species: Azygopus pinnifasciatus NORMAN

1926

Diagnosis: Small, thickset, rather compressed

otoliths; ventral rim shallow, gently curving,

dorsal rim with prominent mediodorsal angles,

posterior tip pointed, ventrally projecting, ante-

rior tip with a short, massive, but pointed ros-

trum, situated inframedianly, a distinct excisura,

and a rather sharp and long antirostrum. Index

l:h 1.3. Otolith size not exceeding 3 mm at most.

Ostium about as wide as cauda and not much

longer. Differentiation of ostium and cauda very

feeble due to poor definition of outline of col-

liculi. Sulcus very deep, v-shaped. Ostium clear-

ly opening anteriorly. Cauda terminating at mod-

erate distance from the posterior tip of the oto-

lith. Circumsulcal depression well developed,

narrow, rather deep.

Inner face rather flat, not smooth; outer face

convex and smooth. Rims smooth and moderate-

ly thickset.

Measurements:

l:h h:t ol:cl oh:ch con.o

pinnifasciatus 1.30 2.2-2.5 1.3-1.4 1.0 2.5-3.0

Side dimorphism: Not apparent.

Discussion: Otoliths of the genus Azygopus re-

semble those of the other three genera in the Sa-

maris Group in all principal aspects, such as ha-

bitus and sulcus morphology. This is also the

reason why I have placed Azygopus in this group.

The fish itself, however, does not show all the

specialized characters observed in the three oth-

er genera. But in Plagiopsetta for instance the

number of rays in the pelvic fins also is not re-

duced. Possibly Plagiopsetta and also Azygopus

represent more plesiomorphic genera in this

group.

Species and distribution: Azygopus is a mono-

specific genus with A. pinnifasciatus restricted to

the temperate waters of southern Australia and

New Zealand.

Fig. 660: Samariscus suineri WEBER & BEAUFORT 1929 – 25 ×

Fig. 661: Samariscus huysmani WEBER 1913 – 25 ×

Figs. 662-663: Samariscus triocellatus WOODS 1984 – 25 ×

660a

661b

661a

662b

660b

616c

660c

663

616d

662a

662c

263

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Azygopus pinnifasciatus NORMAN 1926

Figs. 664-665

Investigated otoliths: 2 otoliths (left and right)

from New Zealand, AUG-V 291 (coll. Grenfell).

Distribution: Southern Australia and New Zea-

land.

Poecilopsettinae

7.7.11 Marleyella Group

Genera: A single genus – Marleyella – from the

Indian Ocean.

Definition and relationship: The otoliths of the

genus Marleyella exhibit a rather plesiomorphic

character status, somewhat resembling Cithari-

dae otoliths. This is expressed by the pentagonal

outline of the otolith, the anterior opening of the

sulcus and the low index ol:cl. On the other hand,

and different from Citharidae, the circumsulcal

depression is already complete and well devel-

oped.

It is assumed that the Marleyella Group repre-

sents an early phylogenetical spin-off from the

main Pleuronectid stem or even a pre-pleuronec-

tid stage and has given raise to the Poecilopsetta

Group (see respective entry). NORMAN (1934),

NELSON (1994) and others related Marleyella

closely to Poecilopsetta and had the two groups as

defined here by otoliths in a separate subfamily

Poecilopsettinae. CHAPLEAU (1993) even sug-

gested family ranking.

Marleyella FOWLER 1925

Type-species: Poecilopsetta bicolorata VON

BONDE 1922

Diagnosis: Thin, moderately elongate otoliths;

ventral rim with distinct medioventral angle,

dorsal rim rounded with postdorsal angle and

pronounced mediodorsal projection, anterior and

posterior tips pointed inframedianly. Index l:h

1.5 to 1.6. Otolith size not much exceeding 3.5 mm.

Ostium slightly wider than cauda and not

much longer. Index ol:cl 1.4 to 1.5. Ostium ante-

riorly opened, only very slightly reduced. Cauda

terminating at moderate distance from the poste-

rior tip of the otolith. Sulcus slightly deepened.

Colliculi well separated. Circumsulcal depression

posteriorly well developed, moderately wide and

deepened.

Inner face slightly convex and rather smooth;

outer face flat and smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

bicolorata 1.50-1.60 3.4 1.40-1.50 1.35-1.65 about 5

Side dimorphism: No data.

Discussion: See entry to group.

Species and distribution: Two species – M. bico-

lorata and M. maldivensis – from the Indian Ocean.

Marleyella bicolorata (VON BONDE 1922)

Figs. 666-667

Investigated otoliths: 2 otoliths (left side) from

off Natal, South Africa, ZMH Ot. 29.1.1995.42 (leg.

BMNH 1922.3.27.5-6) and BMNH 1922.3.27.5-6

(syntypes).

Figs. 664-665: Azygopus pinnifasciatus NORMAN 1926 – 15 ×

664a

665b

665a

664b

665c

664c

264

Schwarzhans: Pleuronectiformes

Distribution: Indian Ocean, chiefly South and

East Africa.

7.7.12 Poecilopsetta Group

Genera: Two genera – Poecilopsetta and Nema-

tops – in relatively deep water in tropical and sub-

tropical seas.

Definition and relationship: The two genera of

the Poecilopsetta Group no doubt are closely relat-

ed to Marleyella and probably have derived from

it. Together they form the subfamily Poecilopset-

tinae (see also respective entry).

Their otoliths are easily recognized by their

almost circular outline (except for the short and

massive rostrum) and the clear cut sulcus with

its rather high index ol:cl and the ostial opening.

In habitus they can be confused with similar look-

ing otoliths of certain Bothid groups, such as the

Arnoglossus or the Monolene-Laeops Group.

Poecilopsetta GÜNTHER 1880

Type-species: Poecilopsetta colorata GÜNTHER

1880

syn. Boopsetta ALCOCK 1896 (type-species:

Boopsetta umbrarum, syn. P. praelongo)

syn. Alaeops JORDAN & STARKS 1904 (type-spe-

cies: Alaeops plinthus)

syn. Paralimanda BREDER 1927 (type-species:

Paralimanda inermis)

Diagnosis: Moderately thickset, almost com-

pletely round otoliths; only the massive but short

rostrum sticking out from it, all rims more or less

gently and regularly curving, sometimes undu-

lating or with a rounded postdorsal angle. Index

l:h 1.0 to 1.3. Otolith size not much exceeding

3 mm. Otoliths below 1.5 mm probably not diag-

nostically mature.

Ostium wider than cauda and usually much

longer. Index ol:cl 1.4 to 2.3. Ostium anteriorly

open or just slightly reduced. Cauda short, termi-

nating at some distance from the posterior tip of

the otolith. Sulcus deepened, at least the colliculi

which are well separated. Circumsulcal depres-

sion well developed, wide and somewhat deep-

ened.

Inner face rather flat, not very smooth; outer

face flat to slightly convex, and smooth. Rims

moderately sharp to thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

plinthus 1.25-1.30 2.8-3.1 1.40-1.80 1.2-1.3 5-7

praelongo 1.00-1.10 3.0 2.00-2.30 1.2 about 6

beanii 1.10 nm 2.00 1.2 nm

albomaculatus 1.15 2.5 2.30 1.4 3.5

zanzibarensis 1.10-1.15 2.7-3.0 1.65-1.85 1.2-1.3 4-5

natalensis 1.10-1.15 3.0 1.80 1.3-1.4 3.5

Side dimorphism: Not very strongly developed.

Otoliths of the eyed side tend to develop a more

pronounced postdorsal angle, a more clear cut

ostial opening and sometimes also less well sep-

arated colliculi.

Variability: Variability seems to be rather limit-

ed in most cases. The characters most commonly

affected are details of the outline. Unfortunately,

this also one of the few features useful to distin-

guish amongst the various species, which some-

times may become very difficult or even impos-

sible with otoliths alone.

Figs. 666-667: Marleyella bicolorata (VON BONDE 1922) – 15 ×

667b

667a

667c

666

265

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: Closely related to Nematops which

may have just slightly more regularly rounded

and fragrant otoliths as compared to Poecilopset-

ta. Differentiation of the various species within

the genus Poecilopsetta often is very difficult by

means of otoliths alone.

Figs. 668-670: Poecilopsetta plinthus (JORDAN & STARKS 1904) – 15 ×

Figs. 671-672: Poecilopsetta praelongo ALCOCK 1894 – 15 ×

Fig. 673: Poecilopsetta albomaculata NORMAN 1938 – 15 ×

Fig. 674: Poecilopsetta beani (GOODE 1881) – 15 ×

668b

668a

670a

669

671

671a

670b

672

673b

673a

671c

674

673c

266

Schwarzhans: Pleuronectiformes

Species and distribution: About 13 species from

the deeper tropical and subtropical seas – P. beanii,

P. inermis and P. megalepis from the tropical West

Atlantic, P. hawaiiensis from Hawaii, P. plinthus

from Japan, P. albomaculata, P. albomarginata, P. co-

lorata, P. natalensis, P. normani, P. praelongo, P. vay-

nei and P. zanzibarensis from the Indian Ocean.

Poecilopsetta plinthus

(JORDAN & STARKS 1904)

Figs. 668-670

Investigated otoliths: 3 otoliths, 1 (left side, fig. )

from the Suruga Bay, Japan, BMNH 1931.8.19.8,

2 (left and right, figs.) from Japan, coll. Ohe No

851227-47.

Discussion: The otoliths of P. plinthus are some-

what less compressed than those of most other

species of the genus and are also characterized

by their relatively low index ol:cl.

Distribution: Coasts of Japan.

Poecilopsetta praelongo ALCOCK 1894

Figs. 671-672

syn. Boopsetta umbrarum ALCOCK 1896

Investigated otoliths: 2 otoliths (left and right)

from the Deutsche Tiefsee-Expedition 1898/99

Stat. 209, ZMH Ot. 30.1.1995.1-2 (leg. ZMH 21160).

Discussion: Otoliths of P. praelongo are probably

the most compressed to be found in this genus so

far, together with P. beanii. Also characteristic is

the very small cauda.

Distribution: Bay of Bengal and Andaman Sea.

Poecilopsetta beanii (GOODE 1881)

Fig. 674

Investigated otoliths: 1 otolith (left side),

28°41’N/86°07’W, BMNH 1931.8.19.10.

Discussion: The only investigated otolith is

slightly eroded by formalin. Nevertheless, it is

characterized by the very compressed appearance

and the very narrow sulcus. It closely resembles

P. praelongo.

Distribution: Gulf of Mexico and coast of New

England.

Poecilopsetta albomaculata NORMAN 1938

Fig. 673

Investigated otoliths: 1 otolith (left side) from

the Maldives Islands, BMNH 1939.5.24.1774-6

(paratype).

Discussion: Rather compact and thickset otolith

with a strongly widened ostium and a nearly

straight anterior part of the ventral rim.

Distribution: Maldives Islands.

Poecilopsetta zanzibarensis NORMAN 1938

Figs. 675-678

Investigated otoliths: 4 otoliths (3 left and 1 right)

from Zanzibar, ZMH Ot. 30.1.1995.3-5 (leg. BMNH

1939.5.24.1777-84) and BMNH 1939.5.24.1777-84

(syntypes).

Discussion: Like P. praelongo a species with a

rather strong postdorsal angle and a more point-

ed rostrum. Unlike P. praelongo the index ol:cl is

rather small.

Distribution: East Africa.

Poecilopsetta natalensis NORMAN 1931

Figs. 679-680

Investigated otoliths: 2 otoliths (left and right)

from off South Africa, Vityaz Stat. 2644, ZMH Ot.

30.1.1995.6-7 (leg. ZMUC; specimens obtained

from a unlabeled fish in jar together with Parac-

itharus macrolepis).

Discussion: Rather thin otolith with a wide os-

tium and a high index ol:cl. Similar to P. zanziba-

rensis and P. albomaculatus.

Distribution: South Africa, off Natal and Dela-

goa Bay.

267

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Nematops GÜNTHER 1880

Type-species: Nematops microstoma GÜNTHER

1880

Diagnosis: Moderately thin, almost completely

round otoliths; only the short and not very mas-

sive rostrum sticking out from it, all rims more or

less gently curving, sometimes undulating. In-

dex l:h about 1.2. Otolith size probably not ex-

ceeding 3 mm.

Ostium not wider than cauda but considera-

bly longer. Index ol:cl about 1.6. Ostium anterior-

ly open. Cauda short, terminating at some dis-

tance from the posterior tip of the otolith. Sulcus

slightly deepened, at least the colliculi which are

rather well separated. Circumsulcal depression

well developed, wide and not very deep.

Inner face rather flat and rather smooth; out-

er face slightly convex, and smooth. Rims mod-

erately sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

grandisquama 1.20 3.0 1.60 1.0 4.5

Side dimorphism: No data.

Discussion: The fishes of the genus Nematops are

very rare. The otolith of a single specimen inves-

tigated does not differ greatly from otoliths of the

closely related genus Poecilopsetta. It is thinner

than most Poecilopsetta otoliths and the narrow

sulcus resembles such species as Poecilopsetta bea-

nii.

Figs. 675-678: Poecilopsetta zanzibarensis NORMAN 1938 – 15 ×

Figs. 679-680: Poecilopsetta natalensis NORMAN 1931 – 15 ×

675b

675a

677

678

676a

679a

676b

680

675c

679b

268

Schwarzhans: Pleuronectiformes

Species and distribution: Four species from the

deeper water of the Indo-Australian Archipela-

go – N. chui, N. grandisquama, N. macrochirus and

M. microstoma.

Nematops grandisquama

WEBER & BEAUFORT 1929

Fig. 681

Investigated otoliths: 1 otolith (left side) from

St. Nikolaas Bay, Bali, BMNH 1933.2.18.16 (para-

type).

Distribution: Chiefly coasts of Bali.

7.8 Soleidae

Genera: Unlike Pleuronectoidei and part of Cy-

noglossidae the Soleidae have never been subject

to a comprehensive revision. Soleid genera (and

species) are often poorly defined and in need for

a general revision. Many genera of doubtful def-

inition have been introduced, mostly through the

work of CHABANAUD (div.). I have adopted

here a more generalized attitude, following the

view expressed by HEEMSTRA & GON (1981), I

have lumped a number of nominally valid gen-

era together. Thus the family Soleidae as present-

ed here contains 37 extant genera plus 3 fossil

otolith-based genera. In alphabetical order they

are: Achiropsis, Achirus, Aesopia, Anisochirus, Apio-

nichthys, Aseraggodes, Austroglossus, Bathysolea,

Brachirus, Catathyridium, Dageichthys, Dexillichthys,

Dicologlossa, Gymnachirus, Heterobuglossus, Hetero-

mycteris, Hypoclinemus, Microbuglossus, Microchi-

rus, Monochirus, Nodogymnus, Parachirus, Pardachi-

rus, Peltorhamphus, Phyllichthys, Pnictes, Pseudae-

sopia, Quenselia, Rendahlia, Solea, Soleichthys,

Soleonasus, Synaptura, Trinectes, Typhlachirus, Van-

straelenia, Zebrias – and the fossil Granulithus,

Praearchirolithus, Pseudopardachirolithus. Rhinosolea

FOWLER 1946 was based on a single anomalous

specimen (SASAKI, written communication) and

is here not regarded as a valid genus.

Definition and relationship: Soleidae are the

amalgamation of all right eyed Soleoidei (the Cy-

noglossidae representing the left eyed Soleoidei).

In past literature they have been subdivided to

various degrees into subfamilies. This was car-

ried furthest by CHABANAUD (1939), who di-

vided the Soleidae into Achiridae and Soleidae.

In Achiridae he recognized the Achirinae and the

Apionichthyinae and in Soleidae, the Soleinae,

Pardachirinae and Heteromycterinae. The limits

of the five subfamilies of CHABANAUD (1939)

correspond well to the otolith grouping as pre-

sented here, but I have subdivided the Soleinae

in four genus groups – the Solea, Synaptura, Bra-

chirus and Zebrias Groups. Separation of Achiri-

dae from Soleidae again was promoted in the

phylogenetical analysis of CHAPLEAU (1993)

with the argument that the Achiridae would rep-

resent the plesiomorphic sistergroup of the re-

maining Soleoidei (see also NELSON, 1994). I

have adhered here to the more traditional view

and keep Achiridae as subfamily Achirinae in the

Soleidae (see NELSON 1984).

Otoliths of the Soleidae typically are com-

pressed with a rather regular round or oval shape,

a somewhat reduced sulcus opening and a ten-

dency towards a shallow sulcus and fused or at

least poorly defined colliculi. Often their inner

face is quite convex and smooth which can best

be shown in lateral views. Thus soleid otoliths in

most instances are quite easily recognized and

differentiated from those of other pleuronectiform

families.

Soleid otolith morphologies can readily be

differentiated into three main groups, to which I

have applied subfamily ranking. These are the

Achirinae (Achirus and Apionichthys Groups), the

Soleinae (Solea, Synaptura, Brachirus and Zebrias

Groups) and the Pardachirinae (Pardachirus and

Heteromycteris Groups, the latter including the

genus Peltorhamphus from NORMAN’s (1934)

Rhombosoleinae, a subfamily of the Pleuronecti-

dae).

Otoliths of the Achirinae are characterized by

a rather elongate, regularly oval outline and a

long cauda. The cauda is in fact almost as long as

Fig. 681: Nematops grandisquama WEBER &

BEAUFORT 1929 – 15 ×

269

Piscium Catalogus, Part Otolithi piscium, Vol. 2

the ostium in most genera. This must be regard-

ed as a plesiomorphic feature which supports

CHAPLEAU’s (1993) phylogenetical analysis.

The otoliths of the Soleinae are similar in

appearance, but usually somewhat more com-

pressed and with a reduced cauda. Also in most

instances their inner face is distinctly convex.

Finally, otoliths of the Pardachirinae are usu-

ally even more compressed, often with an index

l:h of about 1.0 or less and with a short cauda.

The sulcus is shallow as is the circumsulcal de-

pression giving the inner face, which is often

markedly convex, a very smooth appearance. In

some genera a certain tendency toward fused

colliculi and a widened cauda can be observed.

These otoliths (specially from the Heteromycteris

Group) closely resemble cynoglossid otoliths, as

do the fishes of the two groups themselves (e.g.

loss of the pectoral fins; incipiently hooked

mouth). Indeed it seems very likely to me that

the Cynoglossidae evolved from near the

Pardachirinae.

NORMAN (1934) noted that some members

of the pleuronectid subfamily Rhombosoleinae

resemble Soleids but concluded that this was mere

analogy. Otolith analysis shows that the Rhom-

bosoleinae, as then understood, very probably

do not form a natural assemblage and it seems

possible that several of ist genera do not belong

to the family Pleuronectidae at all (see entries to

chapters 5.3.2., the Ammotretis Group, Pleuronecti-

dae and the Samaris, Pelotretis and Rhombosolea

Groups). However, in regard to the non-relation-

ship of the Rhombosoleinae to the Soleidae NOR-

MAN was essentially correct, except in respect of

the genus Peltorhamphus. Although my conclu-

sions are entirely based on otolith analysis I feel

very strongly convinced that Peltorhamphus be-

longs with the Soleidae in the vicinity of Hetero-

mycteris and Rendahlia of the Heteromycteris Group.

In the fossil record soleid otoliths are relative-

ly well known from the Oligocene onward. Ear-

liest findings are from the Eocene of France and

represent the subfamily Pardachirinae. This indi-

cates that the origin of the Soleidae occured rel-

atively early in the history of the Pleuronecti-

formes. Even more, the subdivision of the Solei-

dae into the three main branches was already

established at that time, with the Pardachirinae

probably representing the most apomorphic lin-

eage. This also indicates that the dichotomy that

gave raise to the Soleidae may well pre-date, for

instance, the splitting of the main pleuronectoid

stem into Scophthalmidae, Bothidae and Pleu-

ronectidae, and must have occured at about the

citharid-brachypleurid level. In this respect it is

of interest to note the overall resemblance of

brachypleurid otoliths with soleid otoliths (see

respective entries).

Distribution: Soleidae are widely distributed

throughout the shallow warm seas of the world

oceans and several species ascent into rivers or

are entirely adapted to fresh water. The family is

most speciose and diverse in the tropics. Achirin-

iae are restricted to the Americas and are also

commonly found in freshwater. Soleinae and

Pardachirinae, on the other hand, are exclusively

old world subfamilies, the Pardachirinae with

very few exceptions being confined to the Indo-

Pacific.

Achirinae

7.8.1 Achirus Group

Genera: Trinectes, Achirus, Catathyridium, Hy-

poclinemus, Gymnachirus, Nodogymnus. There are

few undeterminable fossil otolith records from

the Miocene of Trinidad and the Dominican Re-

public.

Definition and relationship: Otoliths of the

Achirus Group probably represent the most ple-

siomorphic ones to be found in the Soleidae.

Outline is rather regularly rounded to oval. The

otoliths are relatively robust with only a moder-

ately convex inner face. Most important though

is the plesiomorphic pattern of the sulcus. The

sulcus is somewhat deepened and the cauda is

not much shorter than the ostium. In few genera

(Gymnachirus, Nodogymnus), which form a small

subgroup in this group, the sulcus is considera-

bly deepened and the colliculi are completely

fused, thus resembling certain morphologies

found in the Zebrias Group (see respective entry).

The genera of the Apionichthys Group are con-

sidered to be closely related, but differ in the al-

ready much reduced cauda.

270

Schwarzhans: Pleuronectiformes

Trinectes RAFINESQUE 1832

Type-species: Trinectes scabra RAFINESQUE 1832

(syn. T. maculatus)

Diagnosis: Moderately thickset, ovale otoliths;

ventral rim shallow and gently curving, dorsal

rim likewise but somewhat more irregularly,

anterior rim rounded, posterior rim cut to slight-

ly concave, usually with prominent angles where

it meets the dorsal and ventral rims. Index l:h

1.15 to 1.35. Otolith size up to 4.5 mm.

Sulcus deepened, rather wide, centrally posi-

tioned, terminating with rounded tips at some

distance from anterior and posterior rims. Os-

tium not or just slightly wider than cauda and

not much longer. Dorsal and ventral depressions

rather wide, moderately deep and well connect-

ed around the cauda to form a circumsulcal de-

pression.

Inner face rather flat, not very smooth, some-

times with irregular marginal ornamentation;

outer face flat, sometimes irregularly ornament-

ed. Rims rather thickset, sometimes irregularly

crenulated.

Measurements:

l:h h:t ol:cl oh:ch con.i

maculatus 1.15-1.35 2.4-3.1 1.05-1.10 1.0 3.5

paulistanus 1.15-1.25 2.9 1.25-1.40 1.2-1.3 3.0-3.2

fonsecensis nm nm 1.45 1.0 2.8

Side dimorphism: Not apparent.

Variability: The variability of otoliths in the spe-

cies of this genus seems to be rather limited. As

the figures of T. maculatus show it mostly con-

cerns the index l:h.

Discussion: Very similar to Achirus of which

Trinectes sometimes is regarded as a subgenus.

Trinectes otoliths seem to generally show a flatter

inner face, a deeper circumsulcal depression and

a lower index ol:cl.

Species and distribution: CHABANAUD (1939)

lists 7 nominally valid species – T. maculatus,

T. paulistanus, T. inscriptus, T. microphthalmus from

the Atlantic coast of America and T. fonsecensis,

T. fluviatilis and T. fimbriatus from the Pacific coast

of America.

Trinectes maculatus

(BLOCH & SCHNEIDER 1801)

Figs. 682-683

syn. Achirus fasciatus LACEPEDE 1803

syn. Pleuronectes mollis MITCHILL 1815

syn. Pleuronectes apoda MITCHILL 1815

syn. Trinectes scabra RAFINESQUE 1832

syn. Solea browni GÜNTHER 1862

syn. Achirus comifer JORDAN & GILBERT 1884

Investigated otoliths: 2 otoliths (left side) from

off New York, USA, ZMH Ot. 12.3.1995.1 (leg.

BMNH 1982.11.10.21-26) and BMNH 1982.11.

10.21-26.

Discussion: Otoliths of T. maculatus are recog-

nized by their very low index ol:cl and oh:ch and

the rather wide sulcus.

Distribution: Atlantic coast of North America

from Massachusetts to the Caribbean.

Figs. 682-683: Trinectes maculatus (BLOCH & SCHNEIDER 1801) – 15 ×

682b

682a

682c

683a

683b

271

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Trinectes paulistanus (RIBEIRO 1915)

Figs. 684-685

syn. Achirus austrinus CHABANAUD 1928

Investigated otoliths: 2 otoliths (left and right)

from British Guiana, ZMH Ot. 12.3.1995.2 (leg.

BMNH 1950.5.15.47-49) and BMNH 1950.5.15.

47-49.

Discussion: Very similar to T. maculatus but with

shorter and narrower cauda.

Distribution: Atlantic coast of South America

from the Guianas to Rio de Janeiro.

Trinectes fonsecensis (GÜNTHER 1862)

Figs. 686

syn. Solea panamensis STEINDACHNER 1876

syn. Solea fischeri STEINDACHNER 1879

Investigated otoliths: 1 dorsally eroded otolith

from the Pacific coast of Panama, BMNH

1903.5.15.249-50.

Distribution: Pacific coast of America in the Gulf

of Panama.

Achirus LACAPEDE 1803

Type-species: Pleuronectes achirus LINNAEUS

1758

syn. Grammichthys KAUP 1858 (type-species:

Pleuronectes lineatus)

syn. Baiostoma BEAN 1882 (type-species: B. bra-

chialis, syn. A. lineatus)

syn. Anathyridium CHABANAUD 1928 (type-

species: Solea gronovii, syn. Achirus achirus)

Diagnosis: Moderately thickset oval to round-

ish otoliths; ventral rim moderately shallow to

deeply and gently curving, dorsal rim shallow,

often somewhat more irregular, anterior rim

rounded, posterior rim broadly rounded or blunt,

but not concave, usually with prominent angles

where it meets the dorsal rim. Index l:h 1.05 to

1.30. Otolith size up to 4.5 mm.

Sulcus somewhat deepened, not very wide,

centrally positioned, terminating with rounded

tips at some distance from anterior and posterior

Figs. 684-685: Trinectes paulistanus (RIBEIRO 1915) – 15 ×

Fig. 686: Trinectes fonsecensis (GÜNTHER 1862) – 10 ×

684b

684a

684c

685a

685b

686b

686a

686c

272

Schwarzhans: Pleuronectiformes

rims. Ostium not or just slightly wider than cau-

da but somewhat longer. Dorsal and ventral de-

pressions rather wide, not very deep and well

connected around the cauda to form a circumsul-

cal depression.

Inner face moderately convex, moderately

smooth, sometimes with irregular marginal or-

namentation; outer face flat to concave, some-

times irregularly ornamented. Rims moderately

thickset sometimes rather sharp and irregularly

crenulated.

Measurements:

l:h h:t ol:cl oh:ch con.i

achirus 1.25-1.30 3.8 1.20-1.40 1.0 3.8

declivis 1.10-1.20 3.0 1.15-1.30 0.9-1.1 2.8-3.4

mazatlanus 1.15-1.25 3.1 1.50-1.80 1.1-1.3 3.4

scutum 1.05-1.10 3.2 1.35-1.45 1.2 2.7

garmani 1.10 3.0 1.25 1.45 2.5

Side dimorphism: Not apparent.

Variability and ontogeny: The level of variabil-

ity is rather restricted and so is the level of on-

togenetic changes as can be seen from the figures

of A. mazatlanus. The critical diagnostic size seems

to be reached with 2 mm of length.

Discussion: Very similar to Trinectes. Achirus oto-

liths usually are more compressed with a more

convex inner face and a shorter cauda.

Species and distribution: At least 14 nominally

valid species – A. achirus, A. declivis, A. garmani,

A. lorentzi, A. lineatus, A. microphthalamus, A. no-

vae, A. opercularis, A. trichospilus, A. zebrinus from

the Atlantic coast of America and A. barnharti,

A. klunzingeri, A. mazatlanus, A. scutum from the

Pacific coast of America.

Achirus achirus (LINNAEUS 1758)

Figs. 687-688

syn. Solea gronovii GÜNTHER 1862

syn. Solea indica GÜNTHER 1862

Investigated otoliths: 2 otoliths from British

Guiana, ZMH Ot. 12.3.1995.3 (leg. ZMH H 871,

fig. 687) and BMNH 1984.8.8.338-344 (fig. 688).

Discussion: Otoliths of A. achirus is immediate-

ly differentiated from other species of the genus

by its more elongate otoliths. In this respect it is

more difficult to distinguish it from species of the

related genera Trinectes and Catathyridium.

Distribution: Tropical Atlantic coast of America.

Achirus declivis CHABANAUD 1940

Figs. 689-692

Investigated otoliths: 4 otoliths (3 left, 1 right)

from Trinidad, ZMH Ot.19.3.1995.1-3 (leg. BMNH

1932.5.9.20-23) and BMNH 1932.5.9.20-23.

Discussion: Otoliths with the typical com-

pressed, roundish outline to be found in this

genus, but with a rather small and narrow sul-

cus.

Distribution: Caribbean.

Figs. 687-688: Achirus achirus (LINNAEUS 1758) – 10 ×

687b

687a

687c

688

273

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Achirus scutum (GÜNTHER 1862)

Figs. 695-696

Investigated otoliths: 2 otoliths (left and right)

from the Pacific coast of Panama, ZMH Ot.

19.3.1995.5 (leg. BMNH 1930.9.2.36) and BMNH

1930.3.1995.5.

Discussion: Otoliths are rather easily recognized

by their more thin appearance and the wide and

somewhat deepened sulcus.

Distribution: Pacific coast of Panama.

Achirus mazatlanus (STEINDACHNER 1869)

Figs. 693-694

syn. Solea pilosa PETERS 1869

Investigated otoliths: 2 otoliths (left side) from

the Mazatlan lagoon, Pacific coast of Mexico,

ZMH Ot. 19.3.1995.4 (leg. BMNH 1982.8.19.2306-

20) and BMNH 1982.8.19.2306-20).

Discussion: Similar to A. declivis, but with more

or less straight dorsal and posterior rims.

Distribution: Tropical coast of Pacific America.

Figs. 689-692: Achirus declivis CHABANAUD 1940 – 15 ×

690b

692

691c

691a

691b

689

690a

274

Schwarzhans: Pleuronectiformes

Achirus garmani JORDAN 1889

Fig. 697

syn. Catathyridium grandiviri (CHABANAUD

1928)

Investigated otoliths: 1 otolith (right side) from

Rio Grande do Sul, Brazil, BMNH 85.2.3.75-76.

Discussion: The sulcus is wide and rather deep

as in A. scutum but the otolith is more thickset.

All rims are rather smooth and gently curved.

Distribution: Southern coasts of Brazil.

Catathyridium CHABANAUD 1928

Type-species: Solea jenynsi GÜNTHER 1862

Diagnosis: Moderately thickset ovale otoliths;

ventral rim shallow and gently curving, dorsal

rim likewise but somewhat more irregularly,

Figs. 693-694: Achirus mazatlanus (STEINDACHNER 1869) – 15 ×

Figs. 695-696: Achirus scutum (GÜNTHER 1862) – 15 ×

Fig. 697: Achirus garmani JORDAN 1889 – 15 ×

694b

696

694c

695a

695b

693

694a

695c

697a

697b

275

Piscium Catalogus, Part Otolithi piscium, Vol. 2

anterior rim rounded, posterior rim cut or also

rounded, sometimes with postdorsal angle. In-

dex l:h 1.25 to 1.45. Otolith size up to 4 mm.

Sulcus deepened, rather wide and long, cen-

trally positioned, terminating with rounded tips

not very far from anterior and posterior rims.

Ostium not or just slightly wider than cauda and

not much longer. Dorsal and ventral depressions

rather wide, shallow and well connected around

the cauda to form a circumsulcal depression.

Inner face moderately convex, irregularly

ornamented, particularly near the otolith mar-

gins; outer face flat, slightly and irregularly orna-

mented. Rims rather thin, irregularly crenulated.

Measurements:

l:h h:t ol:cl oh:ch con.i

jenynsi 1.25-1.45 2.8 1.20-1.25 1.0-1.2 2.8

Side dimorphism: No data.

Variability and ontogeny: Details of the outline

and in particularly strength and nature of the

marginal ornamentation seem to be quite variable.

Smaller specimens of less than 2.5 mm are more

compressed than those of 3 mm and more. Thus

specimens below 2.5 mm may not have devel-

oped all pertinent diagnostically valid characters.

Discussion: Otoliths of Catathyridium closely

resemble those of the genus Achirus, in particular

those of its type-species A. achirus. Characteristic

is the more elongate shape and the rather long

sulcus.

Species and distribution: Catathyridium proba-

bly is a monospecific genus since C. grandiviri

CHABANAUD 1928 may represent a synonym

of Achirus garmani JORDAN 1889 (see respective

entry). C. jenynsi is known from the Atlantic coast

of southern America and in the La Plata and

Paraguay river systems.

Catathyridium jenynsi (GÜNTHER 1862)

Figs. 698-700

Investigated otoliths: 3 otoliths (left side) from

the Paraguay river, ZMH Ot. 19.3.1995.6-8 (leg.

ZMH H878).

Distribution: Atlantic coast of South America,

La Plata and Paraguay rivers.

Hypoclinemus CHABANAUD 1928

Type-species: Hypoclinemus paraguayensis CHA-

BANAUD 1928

Diagnosis: Moderately thickset oval otoliths;

ventral rim gently curving, smooth, dorsal rim

likewise but somewhat irregularly undulating,

anterior rim rounded or slightly pointed, poste-

rior rim bluntly rounded, postdorsal angle may

be present. Index l:h 1.30 to 1.45. Otolith size up

to 3.5 mm.

Sulcus rather deep and wide, centrally posi-

tioned, terminating with rounded tips at some

distance from anterior and posterior rims. Os-

Figs. 698-700: Catathyridium jenynsi (GÜNTHER 1862) – 15 ×

698b

700

699

698a

698c

276

Schwarzhans: Pleuronectiformes

tium and cauda almost fused. Ostium not or just

slightly wider than cauda and not much longer.

Dorsal and ventral depressions rather wide,

moderately deep and well connected around the

cauda to form a circumsulcal depression.

Inner face rather flat, smooth; outer face slight-

ly convex, smooth. Rims rather thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

mentalis 1.30-1.45 2.5 1.20-1.35 1.0-1.1 about 4

Side dimorphism: No data.

Variability: Judging from the two specimens

investigated it seems that the variations are quite

remarkable as far as the outline of the otoliths is

concerned and the index l:h.

Discussion: Otoliths of Hypoclinemus are quite

easily recognized by their deep sulcus with the

nearly fused colliculi. In this respect they resem-

ble otoliths of Gymnachirus and Nodogymnus. The

latter, however, are more thin with a more con-

vex inner face, and show a thinner, anteriorly

pointed sulcus with completely fused colliculi.

Species and distribution: Two species along the

Atlantic shores of South America entering the

Amazonas and Paraguay river systems – H. men-

talis and H. paraguayensis.

Hypoclinemus mentalis (GÜNTHER 1862)

Figs. 701-702

Investigated otoliths: 2 otoliths (left side) from

the Amazonas upstream in Peru, ZMH Ot.

19.3.1995.9-10 (ZMH H879).

Distribution: Atlantic coast of South America

and entering into the Amazonas river system

upstream to Peru.

Gymnachirus KAUP 1858

Type-species: Gymnachirus nudus KAUP 1858

Diagnosis: Rather thin ovale otoliths; ventral rim

shallow, posteriorly almost straight and anterior-

ly steeply ascending to a pointed tip, dorsal rim

more gently curving somewhat irregularly un-

dulating, with a slight concavity towards the

pointed anterior tip, posterior rim cut to slightly

concave, usually with prominent angles where it

meets the dorsal and ventral rims. Index l:h 1.2 to

1.35. Otolith size up to 3.5 mm.

Sulcus deep, rather wide, with completely

fused colliculi, centrally positioned, terminating

with a rounded tip at some distance from poste-

rior rim, but anteriorly pointed and close to the

anterior tip of the otolith. A small ventral inden-

tation of the fused colliculum indicates ostium

and cauda. Ostium not or just slightly wider than

cauda and not much longer. Dorsal and ventral

depressions rather wide, moderately deep and

well connected around the cauda to form a cir-

cumsulcal depression.

Inner face slightly convex, rather smooth ex-

cept for the deep sulcus; outer face flat, smooth.

Rims rather thin.

Measurements:

l:h h:t ol:cl oh:ch con.i

melas 1.20-1.35 3.8 1.35-1.40 nm 3.5

Side dimorphism: No data.

Discussion: The characteristic outline of the oto-

liths and the very deep sulcus with the complete-

Figs. 701-702: Hypoclinemus mentalis (GÜNTHER 1862) – 15 ×

702b

701

702a

702c

277

Piscium Catalogus, Part Otolithi piscium, Vol. 2

ly fused colliculi readily distinguishes otoliths of

the genus Gymnachirus (and those of the related

genus Nodogymnus) from all other achirin gen-

era. In this respect they do resemble certain gen-

era of the Zebrias Group (see respective entry) but

this probably represents parallel evolution or

functional morphological adaption.

CHABANAUD (1940, 1949) not only regard-

ed Nodogymnus as a synonym of Gymnachirus but

also suggested that the two species of Gymnach-

irus and the 5 nominal species of Nodogymnus

(see CHABANAUD, 1939) would represent just

one single species – G. nudus. Apparently, this

view has not been shared in more recent litera-

ture. Knowledge of otoliths from the two nomi-

nal genera is as yet not sufficient to comment.

Species and distribution: Two species – G. nudus

from the Atlantic coast of South America and

G. melas from the Atlantic coast of North America.

Gymnachirus melas NICHOLS 1916

Figs. 703-704

Investigated otoliths: 2 otoliths (left and right)

from off Georgia, USA, ZMH Ot. 9.3.1995.11-12

(leg. Fitch).

Discussion: See entry to genus and to Nodogym-

nus texae.

Distribution: Atlantic coast of North America

and the Bahamas.

Nodogymnus CHABANAUD 1928

Type-species: Gymnachirus fasciatus GÜNTHER

1862

Diagnosis: Rather thin otoliths with nearly rec-

tangular outline; ventral rim shallow, undulat-

ing, posteriorly almost straight and anteriorly

steeply ascending to a pointed tip, dorsal rim more

gently curving and more strongly undulating,

with a slight concavity towards the pointed ante-

rior tip, posterior rim nearly vertically cut, with

prominent angles where it meets the dorsal and

ventral rims. Index l:h about 1.2. Otolith size

probably more than 3 mm.

Sulcus moderately deep, narrow, with com-

pletely fused colliculi, centrally positioned, ter-

minating with a rounded tip at some distance

from posterior rim, anteriorly somewhat nar-

rowed and close to the anterior tip of the otolith.

A small ventral indentation of the fused collicu-

lum indicates ostium and cauda. Ostium just

slightly wider than cauda and somewhat longer.

Dorsal and ventral depressions rather wide,

moderately deep and well connected around the

cauda to form a circumsulcal depression.

Inner face nearly flat, moderately smooth;

outer face flat, slightly ornamented. Rims rather

thin.

Measurements:

l:h h:t ol:cl oh:ch con.i

texae 1.20 3.8 1.55-1.70 1.15 about 4

Side dimorphism: Not apparent.

Discussion: CHABANAUD (1928) suggested

that the two species of Gymnachirus and the five

nominal species of Nodogymnus represent but a

single species – Gymnachirus nudus (see also en-

try to Gymnachirus and Nodogymnus texae).

Species and distribution: According to CHABA-

NAUD (1939) there are five nominal species in

Nodogymnus – N. fasciatus, N. nicholsi, N. williamso-

ni, N. texae from the Atlantic coast of North Amer-

ica and N. zebrinus from the Atlantic coast of South

America.

Nodogymnus texae GUNTER 1936

Figs. 705-706

Investigated otoliths: 2 otoliths (left and right)

from Port Aransas, Texas, ZMH Ot. 19.3.1995.13

(leg. BMNH 1948.8.6.1455-59) and BMNH 1948.8.

6.1455-59.

Discussion: The two otoliths investigated from

N. texae differ from those of Gymnachirus melas in

the more rectangular outline, the undulating

margins and the rather narrow and not so deep

sulcus. Since the specimens investigated are con-

siderably smaller than those of Gymnachirus melas

it is difficult to say how much of these differences

are due to allometric ontogeny (see also entry to

Gymnachirus and Nodogymnus).

Distribution: Coasts of Texas.

278

Schwarzhans: Pleuronectiformes

7.8.2 Apionichthys Group

Genera: Following CHABANAUD (1939) 4 most-

ly monospecific genera from the Atlantic coast of

South America and its rivers are placed in this

group, also otoliths are only known from one of

them. The 4 genera are – Apionichthys, Achiropsis,

Soleonasus and Pnictes.

Definition and relationship: Since CHABA-

NAUD’s review of the Achirinae (1928) the four

genera making up the Apionichthys Group are

thought to be closely related to those of the Achirus

Group. In 1939 CHABANAUD separated them

from the Achirinae in a subfamily of there own,

the Apionichthyinae in the then family Achiridae.

Otoliths have only been available from one

genus of these rare fishes, and any conclusions to

possible relationships are difficult to draw. Nev-

ertheless, this otolith differs from those in the

Achirus Group in two main features. That is the

rather short and reduced cauda and the rather

strongly convex and smooth inner face with the

shallow sulcus. In this respect it much closer re-

sembles otoliths of the Solea Group. Anyhow, more

material has to be awaited for further discussions

of this matter.

Apionichthys KAUP 1858

Type-species: Apionichthys dumerili KAUP 1858

syn. Soleotalpa GÜNTHER 1862 (type-species:

Soleotalpa unicolor, syn. A. dumerili)

Diagnosis: Moderately thickset roundish oto-

liths; ventral rim moderately deep, gently curv-

ing, with rounded postventral angle, dorsal rim

more shallow, with broadly rounded pre- and

postdorsal angles and a wide middorsal notch,

anterior rim broadly rounded, posterior rim near-

ly vertically cut with median notch. Index l:h 1.15.

Otolith size small, probably not exceeding much

2 mm.

Sulcus shallow, rather narrow, centrally posi-

tioned, with rounded terminations anteriorly

Figs. 703-704: Gymnachirus melas NICHOLS 1916 – 15 ×

Figs. 705-706: Nodogymnus texae GUNTER 1936 – 15 ×

703b

704

703a

703c

705b

705a

706b

706a

706c

279

Piscium Catalogus, Part Otolithi piscium, Vol. 2

close to the anterior rim of the otolith. Ostium

not or just slightly wider than cauda, but much

longer. Dorsal and ventral depressions narrow,

rather shallow, but well connected around the

cauda to form a circumsulcal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims rather thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

dumerili 1.15 2.1 2.7 1.15 2.5

Side dimorphism: No data.

Ontogeny: The only investigated otolith of this

genus is less than 1.5 mm long and probably does

not represent a fully adult specimen. Neverthe-

less, its appearance is quite characteristic and I

therefore assume that in this case even very small

otoliths may be diagnostically mature.

Discussion: See entry to group.

Species and distribution: A single species –

A. dumerili – from the coast of the Guianas, South

America.

Apionichthys dumerili KAUP 1858

Fig. 707

syn. Soleotalpa unicolor GÜNTHER 1862

syn. Apionichthys ottonis STEINDACHNER 1868

syn. Apionichthys nebulosus PETERS 1869

syn. Apionichthys bleekeri HARST 1879

Investigated otoliths: 1 otolith (left side) from

British Guiana, BMNH 1984.8.8.336-337.

Distribution: South America, coasts of the Guia-

nas.

Achiropsis STEINDACHNER 1876

Type-species: Achiropsis nattereri STEINDACHN-

ER 1876

Remarks: A specimen of A. nattereri in the ZMUC

collection was x-rayed and revealed that otoliths

have been dissolved (by formalin).

Species and distribution: Two species from the

Atlantic coast of South America – A. nattereri and

A. normani.

Soleonasus EIGENMANN 1912

Type-species: Soleonasus finis EIGENMANN 1912

Remarks: Soleonasus is a monospecific genus –

S. finis. Otoliths of this rare species from the coasts

and rivers of British Guiana have not been avail-

able for investigation.

Pnictes JORDAN 1918

Type-species: Achiropsis asphyxiatus JORDAN &

GOSS 1886

Remarks: Pnictes is a monospecific genus –

P. asphyxiatus. Otoliths of this rare species from

the coast of Brazil and the Amazonas river sys-

tem have not been available for investigation.

Soleinae

7.8.3 Solea Group

Genera: Microchirus, Monochirus, Dicologlossa,

Quenselia, Solea, Dageichthys, Microbuglossus, Bath-

ysolea, Vanstraelenia. This group is also well known

from the fossil record of Europe since Oligocene

times.

Definition and relationship: The genera incor-

porated in this group represent the core of the

Soleinae that probably has given rise to the more

advanced groups of the subfamily discussed lat-

er. Their otoliths come closest to what could be

described as the typical Soleid pattern. They are

roundish, compressed, with a deep ventral and a

shallow dorsal margin. Except for Bathysolea and

Vanstraelenia the inner face is distinctly convex,

the outer face flat or slightly convex. The sulcus

Fig. 707: Apionichthys dumerili KAUP 1858 – 15 ×

280

Schwarzhans: Pleuronectiformes

generally is rather shallow (although the cauda

may be somewhat deepened) anteriorly reaches

close to the rim and is indistinctly separated into

an ostium and a cauda, the latter being some-

what shorter. The circumsulcal depression is well

developed and well connected around the cauda.

As already stated a number of more special-

ized groups may have originated from near the

Solea Group. First to mention is the Synaptura

Group with its characteristic elongated otoliths

and the tendency to develop a bipartite ostium.

Also the Brachirus Group is closely related and its

limits to the Solea Group in fact are somewhat

fluent. Typical members of the Brachirus Group

are characterized by their distinctive otolith out-

line which in fact resembles the Achirinae (see

respective entry). Finally, the Zebrias Group may

have developed from the Brachirus Group. Its

members are characterized by the tendency to

fused colliculi and a deepened sulcus. The Solea

Group thus is regarded as the most plesiomor-

phic unit of the Soleinae.

Microchirus BONAPARTE 1833

Type-species: Pleuronectes microchirus DELARO-

CHE 1809 (syn. M. variegatus)

syn. Buglossus GÜNTHER 1862 (type-species:

Pleuronectes variegatus)

syn. Buglossidium CHABANAUD 1930 (type-spe-

cies: Solea lutea)

syn. Microchiropsis CHABANAUD 1956 (type-

species: Solea boscanion)

Diagnosis: Moderately thickset to thickset com-

pressed otoliths; ventral rim deeply and regular-

ly curving, dorsal rim more shallow, with broad-

ly rounded postdorsal angle, anterior rim broad-

ly rounded, posterior rim blunt, nearly vertically

cut or broadly rounded. Index l:h 1.00 to 1.35.

Otolith size up to 4 mm, diagnostic maturity

reached at about 1.5 to 2.0 mm.

Sulcus rather shallow and narrow, position

slightly supramedian, anteriorly reaching close

to the anterior rim of the otolith. Ostium not wider

than cauda, sometimes more narrow, and not

much longer. Dorsal and ventral depressions rath-

er wide, somewhat deepened and well connect-

ed around the cauda to form a circumsulcal de-

pression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims mostly thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

variegatus 1.05-1.20 2.8-3.5 1.2-1.4 1.0 2.8-3.3

luteus 1.20-1.25 2.3 1.4-2.0 1.0-1.1 3.2-3.5

boscanion 1.15-1.20 3.0 1.1-1.2 1.0 3.0-3.5

†frequens 1.05-1.15 2.5-2.7 1.1-1.4 0.8-1.0 2.0

†kirchbergeanus 1.20-1.35 2.5-3.0 1.1-1.3 1.0 2.8-3.3

†latior 1.00-1.15 2.5 1.2-1.3 1.0 2.5

†wienrichi (ad.) 1.25-1.35 2.3-2.5 1.1-1.3 0.9-1.0 4.0-4.3

†wienrichi (juv.) 1.10-1.20 2.7-3.5 1.1-1.5 0.9-1.2 2.8-3.5

Side dimorphism: Side dimorphism is very fee-

ble in the species of this genus or else submerges

in the considerable variability. Sometimes otoliths

of the right side show less separated colliculi and

some radial furrows within the circumsulcal de-

pression.

Ontogeny and variability: Usually, specimens

below a size of 1.5 to 2 mm do not exhibit all

pertinent diagnostically valid features. They are

so generalized in appearance that they can hard-

ly be separated on species level. An exception

from this is the fossil species M. wienrichi which

shows some special morphological development

in juveniles (see respective entry).

Variability in this genus is rather strong and

mostly concerns the outline of the otoliths and

the proportions of sulcus and otolith. Since the

overall morphological pattern is rather simple, it

can become difficult at times even with adult

specimens to distinguish between related species.

In fossils this means that at times phenotypical

species could in fact represent species groups and

they should be dealt with accordingly and care-

fully.

Discussion: Closely related genera are Monochi-

rus, Dicologlossa and Quenselia. The latter has usu-

ally been placed in synonymy with Microchirus

in recent literature. The typical thin appearance

of the otoliths, however, have led me to regard

Quenselia as a separate genus, morphologically

intermediate between Microchirus and Dicologlos-

sa. Probably even more closely related or synon-

ymous is Monochirus. Also, the two specialized

genera Bathysolea and Vanstraelenia may have

originated from near Microchirus. They are both

characterized by the flat inner face and the mas-

sive convex outer face.

There has been some confusion about the

nature of the genus Buglossidium in literature and

the delimitation of its species as to those of Micro-

chirus. M. boscanion has been regarded at times as

synonym of Buglossidium luteum (TORCHIO

281

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Microchirus. On the other hand she does include

M. (Z.) hexophthalma which is placed here in the

related genus Dicologlossa (although placement

in the genus Quenselia would be a viable alterna-

tive according to otoliths; see respective entries).

Buglossidium was regarded by DESOUTTER as a

valid monospecific genus.

Species and distribution: Regarding Buglossidi-

um as synonymy of Microchirus there are at least

three recent species to be placed in this genus –

M. variegatus, M luteus and M. boscanion – all from

the shores of Europe and North Africa. The ge-

neric status of two further North African species

usually placed in Microchirus – M. wittei and

M. frechkopi – remains uncertain at the time. DE-

SOUTTER (1994) has them in her subgenus Micro-

chirus (see above). They could also be represent-

atives of the genus Quenselia. In addition there

1973), suspected as hybrid of Buglossidium luteum

and M. variegatus (CHABANAUD 1939, but ruled

out by observations of NIELSEN, 1963), or been

placed in Microchirus (DESOUTTER 1994). Hav-

ing studied otolith of the three species in ques-

tion, I must in deed agree that they are very sim-

ilar to each other, in particular so M. luteus and

M. boscanion. The conclusion I have drawn is such

that there does not seem to be much good reason

to keep both genera separate. Based on otolith

analysis I therefore suggest to regard Buglossidi-

um as a junior synonymy of Microchirus.

Recently, the genus Microchirus and related

genera have been revised by DESOUTTER (1994).

In her review Microchirus is split into two sub-

genera – Microchirus and Zevaia. The latter corre-

sponds to the genus Quenselia as presented here,

only that its type-species – Q. ocellata – is exclud-

ed by DESOUTTER and left in her subgenus

Figs. 708-712: Microchirus variegatus (DONOVAN 1808) – 10 ×

708b

712

708a

708c

711b

711a

709b

709a

711c

710b

710a

282

Schwarzhans: Pleuronectiformes

are four fossil species representing the genus from

the Oligocene and Miocene of Europe – M. fre-

quens, M. kirchbergeanus, M. latior and M. wienrichi.

Microchirus variegatus (DONOVAN 1808)

Figs. 708-712

syn. Pleuronectes microchirus DELAROCHE 1809

syn. Pleuronectes mangili RISSO 1810

syn. Pleuronectes fasciatus NARDO 1827

syn. Monochirus lingula COSTA 1847

Investigated otoliths: 3 otoliths from recent spec-

imens (2 left side and 1 right side) from Plymouth,

England, 2 otoliths (figs. 708-709) ZMH Ot.7.5.

1995.1-2 (leg. BMNH 1988.10.11.278-292), 1 oto-

lith (fig. 710) BMNH 1988.10.11.278-292; 2 fossil

otoliths (figs. 711-712) from the Lower Pliocene

of Belgium, harbor of Antwerp, coll. Schwarzhans.

Variability: Morphological variations within this

species like in most species of the genus are quite

considerable concerning outline of the otolith as

well as certain proportions of the otolith and the

sulcus. At the same time the otolith pattern is

very simplified, and therefore distinction from re-

lated species may not always be possible (see

below).

Discussion: Otoliths of M. variegatus are very

similar to those of the two other recent species

investigated – M. boscanion and M. luteus – in most

aspects. Those of M. luteus usually are a bit more

thickset with a higher ol:cl index and those of

M. boscanion show a lower ol:cl index. Of the fos-

sil species M. frequens and M. latior resemble clos-

est. Both are more gently rounded in outline and

show a more strongly convex inner face. Also the

predorsal portion is usually more pronounced

than is the case with M. variegatus. M. frequens

differs further in the unusually low index oh:ch

(less than 1.0) indicating that the cauda is wider

than the ostium. However, differentiation of all

these species by otoliths alone may not always be

possible.

Distribution: Recent in the Mediterranean and

the Northeast-Atlantic from Senegal to North of

the British Isles at depth between 80 and 400 m.

Also known as fossil from the Pliocene and Pleis-

tocene of Belgium. Other fossil records of this

species from the Pliocene of France and the Mid-

dle Miocene of Poland are probably erroneous

(see chapter 4.2).

Microchirus luteus (RISSO 1810)

Figs. 716-717

syn. Monochirus minutus PARNELL 1837

Investigated otoliths: 2 otoliths (left side) from

Plymouth, England, ZMH Ot.7.5.1995.3 (leg.

BMNH 1988.10.11.176-8) and BMNH 1988.10.11.

176-8

Variability: The two specimens figured and those

depicted in various previous publications indi-

cate that the morphological variability found in

this species is even bigger than in M. variegatus,

especially as far as the outline of the otoliths are

concerned.

From this it seems doubtful that otoliths of

M. luteus could always be differentiated from

those of the two related species M. variegatus and

M. boscanion. In fact, the fishes themselves also

seem to be difficult to be distinguished and in the

past obviously have been confused to a certain

extent.

Discussion: See entry to M. variegatus.

Distribution: Mediterranean to western Black

Sea and Northeast-Atlantic from Scotland to

southern Morocco.

Microchirus boscanion (CHABANAUD 1926)

Figs. 713-715

syn. Microchirus australis CHABANAUD 1950

Investigated otoliths: 3 otoliths (2 left side, 1 right

side) from West Africa, 14°W/8°N, ZMH

Ot.7.5.1995.4-5 (leg. BMNH 1956.7.12.16-19) and

BMNH 1956.7.12.16-19.

Variability: Unlike the other two recent species

described above, the variability in M. boscanion

seems to be rather limited.

Discussion: See entry to M. variegatus. – M. bos-

canion at various times has been regarded as a

283

Piscium Catalogus, Part Otolithi piscium, Vol. 2

synonym of M. luteus or as a hybrid of M. luteus

and M. variegatus. Both assumptions are not sub-

stantiated by otolith analysis.

Distribution: West African coast from the

Straight of Gibraltar to Angola, in the North over-

lapping with both M. variegatus and M luteus.

Figs. 713-715: Microchirus boscanion (CHABANAUD 1926) – 15 ×

Figs. 716-717: Microchirus luteus (RISSO 1810) – 15 ×

713b

715

713a

713c

716b

716a

714b

714a

716c

717b

717a

284

Schwarzhans: Pleuronectiformes

Microchirus frequens (STEURBAUT 1984)

Figs. 718-724

[?syn.Solea approximata KOKEN 1891 – KOKEN

1891: pl. 5, fig. 13 – holotype lost, figure

and description of holotype inconclusive,

species rejected]

syn. Solea approximata – WEILER 1942: pl. 4, figs.

44-46

?syn. Solea approximata – WEILER 1942: pl. 4, figs.

47-49, 51,

non fig. 50

?syn. Solea approximata – HEINRICH 1969: pl. 13,

figs. 1,3,5

syn. Solea approximata – SCHWARZHANS 1974:

fig. 57, pl. 3, fig. 15

syn. Microchirus sp. – NOLF & STEURBAUT

1979: pl. 5, figs. 27-29

syn. Solea approximata – MENZEL 1980: pl.

2, fig. 6

syn. Solea approximata – MENZEL 1982: pl. 2,

fig. 5

?syn. Buglossidium aff. approximatum – GAEMERS

& SCHWARZHANS 1982: pl. 2, figs. 12,

24-26, pl. 10, fig. 5

?syn. Soleidarum sp. – GAEMERS & SCHWARZ-

HANS 1982: pl. 10, fig. 4

syn. Solea approximata – MENZEL 1983: pl. 4,

fig. 6

syn. Buglossidium frequens STEURBAUT 1984 –

STEURBAUT 1984: pl. 35, figs. 9-18

syn. Buglossidium approximatum – MÜLLER

1990: pl. 5, fig. 8

syn. Buglossidium approximatum – MÜLLER

1994: pl. 10, figs. 6, 7, 12, 14, 17

syn. Solea approximata – SCHWARZHANS 1994:

figs. 525-528

Figs. 718-724: Microchirus frequens (STEURBAUT 1984) – 15 ×

718b

723

718a

718c

721b

721a

719

720

721c

722

724

285

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Remarks: Practically all publications dealing

with fossil otoliths from the Oligocene and Mio-

cene of the North Sea Basin have cited only one

soleid species – Solea approximata KOKEN 1891.

After having reviewed the type specimens of Bu-

glossidium frequens STEURBAUT 1984 from the

Lower Miocene of France it has become obvious

that this nominal species is identical with those

otoliths described as S. approximata from the

Upper Oligocene of the North Sea Basin. It is not

yet certain whether or not this species also ex-

tends into the Lower Miocene of the North Sea

Basin. Those otoliths I have investigated from the

Miocene of the North Sea Basin all represent a

different species described in the following as

M. wienrichi.

KOKEN (1891) based Solea approximata on a

single and small specimen from the Middle Mio-

cene of Northern Germany. The holotype must

now be regarded as lost. His drawing is so gen-

eralized that it is impossible to judge the nature

of the species from it. It is to remind that a both-

id – Arnoglossus holleri – occurs parallelly and his

drawing is such that it could even represent this

species.

Despite the apparent priority of KOKEN’s

description and the wide usage of Solea approxi-

mata in past literature I therefore propose to re-

ject this species in favor of M. frequens and

M. wienrichi respectively.

Investigated otoliths: Numerous specimens

from the Upper Oligocene of northern Germany;

figured specimens are from Kassel (fig. 722, coll.

Schwarzhans), Meerbusch-Osterath near Düssel-

dorf (fig. 721, coll. Neumann) and Krefeld Kem-

pener Feld (figs. 723-724, coll. Neumann and coll.

Schwarzhans). In addition the type material of

Buglossidium frequens from the Lower Miocene

(Burdigalian) of Paillou (Aqutaine Basin, France)

was reviewed; figured specimens are the holo-

type (IRSNB-P 4251, fig. 718) and two paratypes

(IRSNB-P 4252-53, fig. 719; IRSNB-P 4254-59,

fig. 720).

Ontogeny and variability: Otoliths of less than

2.0 mm (figs. 723-724) are somewhat generalized

in morphology and may not exhibit all pertinent

diagnostic features. In particular the widening of

the cauda, characteristic for this species, may not

be completed.

Like in most species of the genus Microchirus

variability is considerable and concerns detail of

the outline as well as certain proportions of the

sulcus.

Discussion: M. frequens differs from the recent

M. variegatus in the more gently rounded outline,

the pronounced predorsal portion, the more

strongly convex inner face and the rather wide

cauda. M. kirchbergeanus from the Miocene of the

Paratethys is more elongated and M. latior, also

from the Miocene of the Paratethys lacks the

widened cauda and at least in adults is more

compressed. M. wienrichi, finally, from the Mio-

cene of the North Sea Basin is characterized by its

peculiar outline of the otolith, the rather short

sulcus and (in adults) the rather flat inner face.

Distribution: Upper Oligocene and Lower Mi-

ocene of France (Aquitaine Basin), Upper Oli-

gocene (?to Middle Miocene) of northern Germa-

ny, Belgium and the Netherlands. Most if not all

records from the Miocene of the North Sea Basin

represent the species M. wienrichi described as

new in the following.

It is assumed that M. frequens represents an

indigenous species of the North Sea Basin during

Upper Oligocene and with the beginning of Mio-

cene invaded the Northeast Atlantic through the

then opening connection north of the British Isles.

Microchirus kirchbergeanus (H.v.MEYER 1852)

Figs. 725-729

syn. Solea kirchbergeana H.v.MEYER 1852 –

H.v.MEYER 1852: pl. 17, figs. 2-3

syn. Solea antiqua H.v.MEYER 1852 – H.v.MEYER

1852: pl.17, figs. 4-7 (according to WEILER

1955)

syn. Solea subvulgaris SCHUBERT 1906 – SCHU-

BERT 1906: pl. 5, fig. 53,55

syn. Solea kirchbergeana – WEILER 1955: figs. 9-10

(otoliths found in situ)

syn. Solea approximata – JONET 1973: pl. 4, figs.

140-141

?syn. Solea approximata – JONET 1979: pl. 2, fig. 17

syn. Solea kirchbergeana – REICHENBACHER

1988: pl. 1, figs. 5-6

?syn. Dicologlossa sp. – BRZOBOHATY 1989: pl.

2, fig. 7

syn. Dicologlossa aff. cuneata – RADWANSKA

1992: pl. 38, fig. 8

syn. Buglossidium sp. – BRZOBOHATY 1994: pl.

1, fig. 11

286

Schwarzhans: Pleuronectiformes

Remarks: M. kirchbergeanus is the only fossil Pleu-

ronectiform from which otoliths have been de-

scribed in situ (WEILER, 1955). Synonymization

with Solea subvulgaris described by SCHUBERT

(1906) is mainly based on WEILER’s excellent

drawing of the otolith found in situ although it

shows a somewhat atypical undulating outline.

Apparently, WEILER’s specimen was rather

small. Recently, this interpretation has been con-

firmed by two isolated otolith findings of this

species at the type-locality described by RE-

ICHENBACHER (1988).

Investigated otoliths: 6 otoliths, the lectotype

(GBW 1906/1/47a, fig. 727) and 2 paralectotypes

(GBW 1906/1/47c, fig. 726 and GBW 1906/1/47b)

of Solea subvulgaris from the Middle Miocene

(Badenian) of Bad Vöslau, Austria, 1 otolith

(fig. 725) from the Middle Miocene (Badenian) of

Poland (ZPalUW RaK-454, described by RAD-

WANSKA, 1992 as Dicologlossa aff. cuneata) and 2

otoliths (figs. 728-729) from the Lower Miocene

(Burdigalian) from Costa da Caparica, Portugal

(coll. Schwarzhans)

Discussion: Otoliths of M. kirchbergeanus are

more elongate than those of other recent or fossil

species of the genus except for M. wienrichi which,

however, differs in a number of other specialized

features (see respective entry). Other than that

otoliths of M. kirchbergeanus are very generalized

in appearance and not very characteristic.

M. kirchbergeanus is regarded here in rather

wide limits and it may not in fact represent a

single species but possibly a group of two or more

related species that cannot be distinguished by

means of otoliths. This conspicuousness is build

on the very simplified morphology that it exhib-

its, the high variability and the wide distribution

pattern. May be once, when large amounts of data

(from adult specimens) from the various locations

and time intervals have been gathered it could

become possible to distinguish more than one

species. Until such fictional date one should be

aware that M. kirchbergeanus represents a pheno-

typic species or species group.

Distribution: Known from otoliths and skeletons

with otoliths “in situ” from the Middle Miocene

of Bavaria, otoliths alone from Austria, Poland

and the Lower Miocene of Portugal

Figs. 725-729: Microchirus kirchbergeanus (H.v.MEYER 1852) – 15 ×

725b

727a

725a

726c

726a

729

727b

728

726b

287

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Microchirus latior (SCHUBERT 1906)

Figs. 730-733

syn. Solea latior SCHUBERT 1906 – SCHUBERT

1906: pl. 6, figs. 12-14

?syn. Solea latior – ANFOSSI & MOSNA 1979: pl.

4, fig. 14

syn. Microchirus aff. variegatus – BRZOBOHATY

1989: pl. 2, fig. 8

syn. Buglossidium frequens – BRZOBOHATY 1989:

pl. 2, fig. 9

syn. Microchirus aff. variegatus – RADWANSKA

1992: pl. 38, fig. 9

Investigated otoliths: 5 otoliths, the lectotype

(GBW 1906/1/58b, fig. 731) and 2 paralectotypes

(GBW 1906/1/58a, fig. 732, GBW 1906/1/58c)

from the Middle Miocene (Badenian) of Bad

Vöslau, Austria, 1 otolith (fig. 733) from the Mid-

dle Miocene (Badenian) of Poland (ZPalUW RaNi-

448, described as Microchirus aff. variegatus by

RADWANSKA, 1992), 1 otolith (fig. 730) from the

Lower Miocene (Eggenburgian) of Mold, Austria

(coll. Schwarzhans).

Discussion: Very close to M. variegatus, but dif-

fering in the more regularly and gently curving

outline and the more convex inner face. M. latior

shows the most compressed otoliths of all Micro-

chirus species, at least in adults.

Distribution: Lower and Middle Miocene of

Austria, Czechoslovakia and Poland.

Microchirus wienrichi n.sp.

Figs. 734-741

?syn. Solea approximata – WEILER 1958: pl. 3,

fig. 17-19

syn. Solea approximata – GAEMERS 1971: pl. 3,

fig. 16, pl. 9, fig. 5

syn. Solea approximata – NOLF 1976: pl. 17, figs.

21-23

syn. Buglossidium approximatum – HUYGHE-

BAERT & NOLF 1979: pl. 6, figs. 22, 23, ?24

syn. Soleidarum sp. 2 – GAEMERS & SCHWARZ-

HANS 1982: pl. 2, fig. 24

Name: In honor of Günther Wienrich (Weetze,

NW-Germany), who has collected most of the

type-material.

Holotype: Fig. 737, SMF P 9321.

Type locality: Water well Lüllingen near Keve-

laer, NW-Germany.

Age: Reinbekian, lower Middle Miocene.

Paratypes: 9 otoliths, 7 topo- and stratitypic (figs.

736, 738-741, SMF P 9322), 1 Reinbekian of Din-

gden near Bocholt (fig. 734, SMF P 9323) and 1

Hemmoorian (fig. 735), Lower Miocene from

Miste near Winterswijk (Netherlands) (SMF P

9324).

Diagnosis: Compressed, moderately small oto-

liths with almost circular outline. Predorsal projec-

tion angular, but not very strong, postdorsal pro-

jection strong, postventral angle shifted far back-

wards, posterior rim undulating in juveniles.

Figs. 730-733: Microchirus latior (SCHUBERT 1906) – 15 ×

732

731a

731c

733

730

731b

288

Schwarzhans: Pleuronectiformes

Sulcus rather short, terminating at considerable

distance from the posterior rim of the otolith.

Otoliths thin and inner face convex in juveniles,

more thickset and with flattened inner face in

adults.

Description: Outline: Otoliths small (not exceed-

ing 3 mm) with compressed, roundish outline.

Dorsal rim often with angular but not very strong

predorsal projection and massive rounded post-

dorsal projection, postventral portion sometimes

angular, shifted far backwards; anterior and pos-

terior tips blunt, the latter often undulating. Oto-

liths moderately thickset.

Inner Face: Convex in juveniles, rather flat in

adults, smooth. Sulcus rather short, terminating

at considerable distance from the posterior tip of

the otolith, rather narrow and moderately deep.

Ostium not much longer than cauda and usually

not wider, too. Colliculi indistinctly separated and

somewhat deepened. Circumsulcal depression

well developed and rather wide.

Other views: Rims smooth, sharp in juveniles,

thickset in adults. Outer face smooth, almost flat

in juveniles, convex in adults.

Side dimorphism: Not apparent.

Figs. 734-741: Microchirus wienrichi n.sp. – 15 ×

736b

738a

735a

734c

734a

737a

735b

736a

734b

736b

738a

737a

739

740b 740a

741

289

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Ontogeny and variability: M. wienrichi is a spe-

cies with a rather unusual high degree of ontoge-

netic changes. Smaller otoliths to approximately

1.7 mm (figs. 738-741) are more compressed, show

a more undulating outline, are rather thin with a

convex inner face and a nearly flat outer face and

exhibit a more narrow sulcus. Larger otoliths

above 2.0 mm (figs. 734-736) are slightly more

elongate, much more thickset with a flattened

inner face and a convex outer face and show a

wider sulcus and a smoothed outline. In fact this

is one of the rare instances where juvenile oto-

liths can be identified easier than adults.

Variability in this species is moderate, mostly

concerning details of the outline and the width of

the sulcus. Anyhow, specimens of M. wienrichi

remain more characteristic than those of most

other species of Microchirus.

Discussion: The diagnostic pattern of M. wien-

richi distinguishes it well from other otoliths of

the genus including M. frequens from the Upper

Oligocene of the area.

Remarks: The reason for rejection of the species

Solea approximata, which otherwise could be in

conflict with M. wienrichi, is given in the descrip-

tion of M. frequens.

Distribution: Lower and Middle Miocene of

northern Germany, Belgium and the Netherlands.

Monochirus RAFINESQUE 1814

Type-species: Monochirus hispidus RAFINESQUE

1814

Diagnosis: Moderately thin, rather elongate oto-

liths; ventral rim moderately deep and regularly

curving, dorsal rim more shallow, with somewhat

anteriorly projecting predorsal angle, anterior rim

inclined, posterior rim rounded. Index l:h 1.30 to

1.35. Otolith size small, not exceeding 3 mm.

Sulcus not much deepened and rather nar-

row, position slightly supramedian, anteriorly

reaching close to the anterior rim of the otolith.

Ostium not wider than cauda, but much longer.

Colliculi poorly defined and poorly separated.

Dorsal and ventral depressions rather wide, some-

what deepened and well connected around the

cauda to form a circumsulcal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims rather sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

hispidus 1.30-1.35 2.8-3.0 1.6 1.0 2.8-3.0

Side dimorphism: Otoliths of the right (eyed)

side show a narrower sulcus, a complete lack of

the separation of the colliculi and some radial

furrows in the zone near to the circumsulcal de-

pression.

Discussion: Monochirus apparently is closely re-

lated to Microchirus and in fact judging from the

otoliths the latter could even be placed included

as a synonymy. Main differences are the more

elongate shape of the otolith and the poorly de-

fined separation of the colliculi.

Species and distribution: Monochirus is a mon-

ospecific genus with M. hispidus distributed

throughout the Mediterranean and in the North-

east-Atlantic from Portugal to Ghana.

Monochirus hispidus RAFINESQUE 1814

Figs. 742-744

syn. Pleuronectes trichodactylus NARDO 1827

syn. Monochirus atlanticus CHABANAUD 1949

Investigated otoliths: 3 otoliths (2 left side, 1 right

side) without location, IRSNB (coll. Nolf, leg.

Chaine).

Distribution: Mediterranean and NE-Atlantic

from Portugal to Ghana at depth down to 250 m.

Quenselia JORDAN 1889

Type-species: Pleuronectes ocellatus LINNAEUS

1758

syn. Echinosolea CHABANAUD 1927 (type-spe-

cies: Pleuronectes ocellatus)

syn. Zevaia CHABANAUD 1943 (type-species:

Solea azevia)

Diagnosis: Thin otoliths with very regular round-

ish outline; ventral rim deeply and very regular-

ly curving, dorsal rim also regularly rounded,

but sometimes with pre- and/or postdorsal an-

gles, anterior and posterior rims broadly round-

ed. Index l:h 1.15 to 1.25. Otolith size up to 5 mm,

diagnostic maturity reached relatively early at

290

Schwarzhans: Pleuronectiformes

about 1.5 mm.

Sulcus shallow, narrow and rather long, posi-

tion slightly supramedian, anteriorly reaching

close to the anterior rim of the otolith. Ostium

not wider than cauda, sometimes more narrow,

but much longer (except for the fossil Q. cornuta,

the only Soleid in which the cauda is longer than

the ostium). Dorsal and ventral depressions nar-

row, not very deep and well connected around

the cauda to form a circumsulcal depression.

Inner face markedly convex, smooth or deli-

cately ornamented towards the rims; outer face

flat to slightly concave, smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

ocellata 1.25 3.7-4.0 1.2-1.5 0.9-1.0 3.0

azevia 1.25 4.2-4.6 1.3-1.5 0.9 3.0-3.5

†cornuta 1.05-1.15 3.0-3.2 0.5-0.7 1.0 2.5-2.7

Side dimorphism: Side dimorphism is very fee-

ble in the species of this genus or else submerges

in the variability.

Ontogeny and variability: Smaller otoliths are

only known from the somewhat peculiar fossil

species. However, even small specimens below

1.5 mm are quite characteristic and unmistakable.

Also the level of variability in this genus is

rather restricted, mainly concerning details of the

outline of the otolith and the ornamentation on

the inner face.

Discussion: In recent ichthyological literature

Quenselia is usually understood as a junior syno-

nym of Microchirus. The otolith pattern, however,

has let me to regard Quenselia as a valid genus

and separate it from Microchirus. Quenselia oto-

liths are characterized by their very thin appear-

ance and the very regular ovale outline.

Morphologically, they are intermediate be-

tween those of Microchirus and the related genus

Dicologlossa, probably representing a lineage of

specialization. Dicologlossa otoliths are more elon-

gate and show a tendency to enlarge their caudal

colliculum. (This is a similar trend as is observed

in the peculiar fossil Q. cornuta.) Dicologlossa

hexophthalma represents an almost perfect link be-

tween the two genera (see respective entry).

In a recent review of the genus Microchirus

DESOUTTER (1994) regarded Quenselia as a syn-

onym, discriminating two subgenera – Microchirus

and Zevaia (for more details see entry to Micro-

chirus). Otolith analysis does not support DE-

SOUTTER’s view of the type-species – Q. ocellata –

to represent a member of the genus Microchirus.

Figs. 742-744: Monochirus hispidus RAFINESQUE 1814 – 15 ×

742b

742a

742c

743

742d

744b

744a

291

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Species and distribution: There are at least two

recent species in the genus Quenselia – Q. ocellata

and Q. theophila – known from the Mediterrane-

an and the Northeast Atlantic. The generic status

of two further African species usually placed in

Microchirus – M. wittei and M. frechkopi – remains

uncertain at the time (see also entry to Microchi-

rus). Although placed into Microchirus by DE-

SOUTTER (1994), they have also been regarded

as representatives the genus Quenselia by

CHABANAUD (1955). In addition, there is one

fossil species placed in this genus – Q. cornuta –

from the Lower Pliocene of NW-Morocco.

Figs. 745-748: Quenselia ocellata (LINNAEUS 1758) – 10 ×

Figs. 749-750: Quenselia theophila (RISSO 1810) – 10 ×

746b

745a

745c

747

746a

745b

748

750b

749a

749c

750a

749b

292

Schwarzhans: Pleuronectiformes

Quenselia ocellata (LINNAEUS 1758)

Figs. 745-748

syn. Solea quadriocellata von BONDE 1922

Investigated otoliths: 4 otoliths (2 left side and

2 right side) from Teneriffa, Canary Islands, ZMH

Ot.9.5.1995.1-4 (coll. Schwarzhans).

Discussion: Very similar to Q. azevia, but may

be less thin and less ornamented on the inner

face. Distinction of the two species by otoliths

alone, however, will be very difficult.

Distribution: Mediterranean and Northeast-At-

lantic from Spain to Mauritania and including

Madeira and the Canary Islands from shallow

depth to 300 m.

Quenselia theophila (RISSO 1810)

Figs. 749-750

syn. Quenselia azevia (CAPELLO 1867)

Investigated otoliths: 2 otoliths (left and right

side) from Portugal, ZMH Ot.9.5.1995.5 (leg.

BMNH 1867.7.23.8) and BMNH 1867.7.23.8.

Discussion: Very similar to Q. ocellata but even

more thin and with intense delicate ornamenta-

tion on the inner face.

Distribution: Western Mediterranean and North-

east-Atlantic from Portugal to Senegal.

Quenselia cornuta n.sp.

Figs. 751-758

Name: cornutus (lat.) = horn bearing, referring

to the hornlike predorsal projection.

Holotype: Fig. 752, SMF P 9325.

Type locality: River banks of the Oued Beth due

South of Dar Bel Hamri, northern Morocco.

Age: Zanclian, Lower Pliocene.

Paratypes: 6 otoliths (figs. 751, 753-757), topo-

and stratitypic, SMF P 9326.

Figs. 751-758: Quenselia cornuta n.sp. – 15 ×

752b

751a 752c

754

752a

751b

755

753b

758a

757

756

753a

758b

293

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Diagnosis: Small roundish otoliths with convex

inner face. Predorsal projection hornlike. Caudal

colliculum about twice as long as ostial colliculum.

Description: Outline: Otoliths small (less than

2.5 mm), with compressed, irregularly roundish

outline. Dorsal rim with prominent predorsal

hornlike projection, postdorsally broadly round-

ed; ventral rim deeply curving; anterior and pos-

terior rims broadly rounded, the posterior one

more blunt so. Otoliths rather thin.

Inner face: Rather strongly convex and

smooth. Sulcus rather short and narrow, with

slightly supramedian position and not much

deepened. This is the only Soleid species in which

the caudal colliculum is considerably longer than

the ostial colliculum (about two times). The sep-

aration of the colliculi is rather distinct. Circum-

sulcal depression narrow, shallow, but well con-

nected around the caudal tip of the sulcus.

Other views: Outer face smooth, almost flat.

Rims sharp.

Side dimorphism: In otoliths of the right side

the hornlike predorsal projection seems to be

generally less well developed.

Ontogeny and variability: Specimens are present

down to about 1 mm in size but do not show any

major ontogenetic changes.

Variability likewise is rather moderate, re-

stricted mainly to details of the outline and pro-

portions of the sulcus.

Discussion: This species is immediately recog-

nized by its unusually long cauda which is about

two times as long as the ostium, a unique charac-

ter amongst otoliths of the Soleidae. This and the

compressed outline with the hornlike predorsal

projection result in a very typical morphology

which only tentatively is placed in the genus

Quenselia. A single finding of a similar otolith from

the Upper Miocene (Tortonian) of Cacela in south-

ern Portugal (fig. 758, coll. Schwarzhans) differs

in the lack of the extended cauda. It is referred to

as Q. aff. cornuta. If this otolith represents the

predecessor of Q. cornuta, as it seems likely, this

would be an indication that the peculiar expan-

sion of cauda and caudal colliculum is a derived

feature not to be mistaken with the plesiomor-

phic long cauda found in members of the Psetto-

didae and the Tephrinectes, Paralichthodes and

Ammotretis Groups.

Dicologlossa CHABANAUD 1927

Type-species: Solea cuneata MOREAU 1881

syn. Xenobuglossus CHABANAUD 1950 (type-

species: X. elongatus)

Diagnosis: Thin and rather elongate otoliths;

ventral rim shallow and regularly curving, dor-

sal rim also shallow, with broadly rounded pre-

and postdorsal angles, anterior and posterior rims

broadly rounded. Index l:h 1.20 to 1.70. Otolith

size up to 5 mm, diagnostic maturity reached at

about 1.5 mm.

Sulcus rather shallow and narrow, position

almost median, anteriorly reaching close to the

anterior rim of the otolith. Ostium not wider than

cauda, sometimes more narrow, and about equal

in length. Dorsal and ventral depressions rather

narrow, somewhat deepened and well connected

around the cauda to form a circumsulcal depres-

sion.

Inner face convex, smooth; outer face almost

flat, smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

hexophthalma 1.40-1.45 4.5 0.85-1.05 0.8-0.9 5.5

cuneata (left) 1.45-1.70 3.2-3.7 1.60-1.80 1.0 3.5-4.0

cuneata (right) 1.45-1.55 3.2-3.7 1.05-1.10 1.0 3.5-4.0

†patens 1.20-1.35 3.0 1.60-1.70 1.1 2.5-2.8

Side dimorphism: Only apparent in D. cuneata.

There, otoliths of the right side have a much more

expanded cauda, almost to the size of the ostium,

whereas in otoliths of the left side the cauda is

much shorter than the ostium.

Ontogeny and variability: As in the related ge-

nus Quenselia ontogenetic changes seem to be

rather small.

Variability is quite changeable in the species

of this genus. In D. hexophthalma it remains at a

low level, in the fossil D. patens it is moderate,

but in D. cuneata it is considerable. There, mostly

features of the outline and proportions of the oto-

liths are concerned.

Discussion: Dicologlossa is closely related to

Quenselia and marks the final stage of lineage

probably having originated from near Microchi-

rus. Like the fossil Quenselia cornuta, otoliths of

the genus Dicologlossa show a tendency to en-

large its cauda (but not as much – only to about

the length of the ostium).

294

Schwarzhans: Pleuronectiformes

Species and distribution: Two recent species –

D. hexophthalma and D. cuneata – from the Medi-

terranean and the Northeast-Atlantic and one

fossil species – D. patens – from the Miocene of

Italy, Austria, France and Portugal. D. hexophthal-

ma was regarded by DESOUTTER (1994) as a

member of the genus Microchirus subgenus Zevaia

(here as Quenselia; see also entry to Microchirus).

Dicologlossa hexophthalma

(BENNETT 1831)

Figs. 759-762

Investigated otoliths: 4 otoliths (2 left side and

2 right side), 2 from Lagos, Portugal and 2 from

Teneriffa, Canary Islands, ZMH Ot.9.5.1995.6-9

(coll. Schwarzhans).

Discussion: Otoliths of D. hexophthalma are less

elongate than those of D. cuneata and also show

always an extended cauda to about the size of the

ostium. They also resemble otoliths of the genus

Quenselia in habitus, differing mainly in being

more elongate. Thus C. hexophthalma is morpho-

logically intermediate between Quenselia and

C. cuneata.

Distribution: Northeastern Atlantic from Portu-

gal to Angola including Madeira and the Canary

Islands.

Dicologlossa cuneata

([DE LA PYLAIE 1835] MOREAU 1881)

Figs. 763-766, 23

syn. Solea angulosa KAUP 1858

syn. Solea clerveleyi GILCHRIST 1906

syn. Solea senegalensis mbaoensis PELLEGRIN 1907

syn. Xenobuglossus elongatus CHABANAUD 1950

Investigated otoliths: 8 otoliths (4 left and 4 right

side), 4 from Portugal and 4 from La Rochelle,

France, ZMH Ot.9.5.1995.10-17 (coll. Schwarz-

hans).

Side dimorphism: Otoliths of the right side ex-

hibit an enlarged cauda, whereas those of the left

side do not.

Variability: Variability in this species is consid-

erable and concerns the outline and the propor-

tions of the otoliths. Occasionally, the posterior

rim is expanded dorsally and pointed (fig. 766).

Figs. 759-762: Dicologlossa hexophthalma (BENNETT 1831) – 10 ×

761

759c

759a

759b

762

760

295

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: See entry to D. hexophthalma.

Distribution: Western Mediterranean and North-

east-Atlantic from the Bay of Biscay to the Cape

of Good Hope.

Dicologlossa patens (BASSOLI 1906)

Figs. 767-769

syn. Solea patens BASSOLI 1906 – BASSOLI 1906:

pl. 2, fig. 4

syn. Solea kokeni SCHUBERT 1906 – SCHUBERT

1906: pl. 20, fig. 8

syn. Solea kokeni – JONET 1973: pl. 4, fig. 144

syn. Pegusa sp. – NOLF & STEURBAUT 1979:

pl. 5, fig. 30

syn. Solea kokeni – ANFOSSI & MOSNA 1979:

pl. 4, fig. 15

syn. Solea aff. kokeni – JONET 1980: pl. 2, fig. 21

syn. Solea patens – STEURBAUT & JONET 1981:

pl. 4, fig. 7

syn. Dicologlossa cuneata – STEURBAUT & JONET

1981: pl. 4, figs. 10-11

syn. Solea patens – STEURBAUT 1984: pl. 36,

figs. 1-4

syn. Solea solea – RADWANSKA 1992: pl. 38,

figs. 13-14

Investigated otoliths: 6 otoliths, the holotype of

Solea kokeni (GBW 1906/1/55, fig. 768) from the

Middle Miocene, Badenian of Bad Vöslau, Aus-

tria, 1 otolith from the Burdigalian, Lower Mio-

cene of Costa da Caparica, Portugal (coll.

Schwarzhans, fig. 769), 3 otoliths from the Bade-

nian, Middle Miocene of Poland (ZPalUW RaK-

447,452,453; described by Radwanska as Solea

solea; fig. 767).

Discussion: Otoliths of D. patens are more com-

pressed and more robust than those of the two

recent species and also do not show an extended

cauda. Quite clearly, they exhibit the most plesi-

omorphic otolith pattern in this genus.

Distribution: Lower to Upper Miocene of Italy,

Austria, France and Portugal

Solea QUENSEL 1806

Type-species: Solea vulgaris QUENSEL 1806

syn. Pegusa GÜNTHER 1862 (type-species: Solea

pegusa, syn. S. lascaris)

syn. Synapturichthys CHABANAUD 1927 (type-

species: Synaptura sauvignyi, syn. S. kleini)

syn. Barnardichthys CHABANAUD 1927 (type-

species: Solea fulvomarginata)

Diagnosis: Moderately thickset to thickset, com-

pressed to elongate otoliths; ventral rim moder-

ately deep to deeply and regularly curving, dor-

sal rim more shallow, anteriorly broadly round-

ed, but posterior-dorsal portion usually extended

and pointed, anterior rim broadly rounded, pos-

terior rim blunt, often nearly vertically cut and

with distinct concavity. Index l:h 1.10 to 1.50.

Otolith size up to 4 mm, rarely up to 5.5 mm,

diagnostic maturity reached at about 1.5 mm.

Sulcus somewhat deepened and rather nar-

row, position slightly supramedian, anteriorly

reaching close to the anterior rim of the otolith.

Ostium not or only slightly wider than cauda and

much longer. Dorsal and ventral depressions

moderately wide, somewhat deepened and well

connected around the cauda to form a circumsul-

cal depression.

Inner face markedly convex, not very smooth;

outer face flat to slightly concave, smooth. Rims

thin to moderately thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

senegalensis 1.40 3.0-3.3 1.7-2.1 1.0 3.3-3.7

triophthalma 1.45-1.50 3.5 1.9-2.2 1.1-1.2 3.0

aegyptiaca 1.25 3.3 1.8 1.1 3.3

†rotunda 1.15-1.25 2.0-2.5 1.5-2.3 1.0-1.2 1.7-2.2

vulgaris 1.20 3.0-3.2 1.4-1.7 1.1-1.2 2.3-2.5

lascaris 1.10 3.1-3.3 1.8-1.9 1.1-1.3 2.4-2.5

nasuta 1.15-1.20 3.0 2.3-2.4 1.1 2.3

kleini 1.10 3.6 1.7 1.0 3.0

Side dimorphism: Only occasionally apparent.

In some species the otoliths of the right side show

a more strongly convex inner face than those of

the left side.

Ontogeny and variability: Both ontogenetic

changes and intraspecific variability in the species

of this genus seem to be at rather moderate level.

296

Schwarzhans: Pleuronectiformes

Discussion: Most species of the genus Solea share

the following features that readily distinguishes

them from other genera of the group. This is the

combine of a rather strongly convex inner face,

the concave posterior rim and the rather high

ol:cl index. Only few species, such as

S. triophthalmus, S. aegyptiaca and possibly also

S. bleekeri lack the concavity of the posterior rim.

In most recent literature several of the species

listed here under the genus Solea are being placed

in a separate genus – Pegusa – based on the en-

larged and specialized nostril on the blind side.

However, otolith analysis does not seem to fol-

low the same tracks. I have therefore chosen

TORCHIO’s (1973) view and regard Pegusa as a

junior synonym of Solea. Nevertheless, the oto-

lith morphologies found in Solea can be differen-

tiated into three distinctive groups, which if ver-

ified by other ichthyological methods should be

given generic or subgeneric ranking. The three

groups are characterized as follows.

Otoliths of S. senegalensis differ from all other

members of the genus in the combination of be-

ing more elongate and showing a more flat inner

face. They are also the ones growing to the larg-

est size. There is quite some overall resemblance

to otoliths of the genus Austroglossus the most

plesiomorphic genus in the Synaptura Group and

maybe this is from near where the Synaptura

Group could have developed.

The second group contains those species with-

out the concavity at the posterior rim – S. trioph-

thalma, S. aegyptiaca and probably also S. bleekeri

(judging from a very eroded otolith investigated).

Figs. 763-766: Dicologlossa cuneata (DE LA PYLAIE 1835) – 10 ×

Figs. 767-769: Dicologlossa patens (BASSOLI 1906) – 15 ×

765b

763a

763c

767a

765a

763b

767b

766

768b

768c

768a

764

769

297

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Finally, the third and largest group contains

those species with a compressed outline, a strong-

ly convex inner face and most notably a concave

posterior rim. To this group belong all those spe-

cies traditionally placed in the genus Pegusa such

as S. lascaris, S. nasuta and S. kleini, but also the

type-species of the genus Solea – S. vulgaris. In

addition, the fossil S. rotunda belongs to this group

as well.

Species and distribution: There are at least 11

valid recent species in Solea distributed through

the Mediterranean and the eastern Atlantic all

the way from Europe to the tip of South Africa –

S. aegyptiaca, S. bleekeri, (otoliths figured in

SMALE et al. 1995), S. fulvomarginata, S. impar,

S. kleini, S. lascaris, S. nasuta, S. senegalensis, S. stan-

alandi, S. vulgaris and S. triophthalma. Of all the

fossil species formally recorded for Solea (more in

the sense of a Soleidae) only one – S. rotunda –

from the Miocene of France and Poland may re-

main in it.

Solea senegalensis KAUP 1858

Figs. 770-771

syn. Solea melanochira MOREAU 1874

Investigated otoliths: 2 otoliths (left and right

side) from off Mauritania, ZMH Ot.9.5.1995.18-

19 (coll. Schwarzhans, leg. W. Schmidt).

Discussion: Otoliths of S senegalensis are easily

recognized by their elongate shape, the relatively

flat inner face and the presence of a slight con-

cavity at the posterior rim.

Distribution: Northeast Atlantic from Portugal

to Senegal at shallow depth down to 80 m.

Solea triophthalma BLEEKER 1863

Figs. 772-773

Investigated otoliths: 2 otoliths (left and right

side) from tropical West Africa, ZMH

Ot.9.5.1995.20 (leg. BMNH 1953.6.22.2) and

BMNH 1953.6.22.2.

Discussion: Otoliths of S. triophthalma are recog-

nized by the elongate shape, the lack of the pos-

terior concavity and the very thin appearance with

a convex inner and a concave outer face.

Distribution: Tropical West Africa.

Solea aegyptiaca CHABANAUD 1927

Fig. 784

Investigated otoliths: 1 otolith (left side) from

the Suez Channel, Egypt, BMNH 1925.9.19.142.

Figs. 770-771: Solea senegalensis KAUP 1858 – 10 ×

770a

770b

771b

770c

771a

298

Schwarzhans: Pleuronectiformes

Discussion: Similar to S. triophthalma but more

compressed.

Distribution: Mediterranean coast of North Af-

rica and entering into the Suez Channel.

Solea rotunda (PRIEM 1914)

Figs. 774-777

syn. Gobius rotundus PRIEM 1914 – PRIEM 1914:

fig. 66

syn. Solea rotunda – STEURBAUT 1984: pl.36,

figs. 5-8

syn. Solea solea – RADWANSKA 1992: pl. 38,

figs. 10-12

Investigated otoliths: 5 otoliths, 2 from the Bur-

digalian (Lower Miocene) of Pont Pourquey,

Aquitaine Basin, France (IRSNB P 4272, 4273; figs.

774-775) and 3 from the Badenian, Middle Mio-

cene of Poland (ZPalUW RaR-449, RaK-450, RaNi-

451; described by RADWANSKA, 1992 as Solea

solea; figs. 776-777).

Discussion: Also somewhat variable in expres-

sion otoliths of this species are best recognized

by their near circular outline. The posterior rim,

however, is still concave.

Distribution: Lower Miocene of France (Aqui-

taine Basin), Middle Miocene of Poland.

Figs. 772-773: Solea triophthalmua BLEEKER 1863 – 10 ×

Figs. 774-777: Solea rotunda (PRIEM 1914) – 15 ×

772b

772a

772c

777

774a

774b

776c

776a

776b

774c

775a

773

775b

299

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Solea vulgaris QUENSEL 1806

Figs. 782-783

?syn. Pleuronectes solea LINNAEUS 1758

Investigated otoliths: 4 otoliths (2 left and 2 right

side) from the German North Sea, ZMH

Ot.9.5.1995.21-24 (coll. Schwarzhans).

Discussion: Very similar to S. lascaris, but gener-

ally somewhat more elongate and with a wider

sulcus. A large series of otoliths of this species

was also figured by CHAINE (1936).

Distribution: North Sea, western Baltic Sea,

Northeast-Atlantic from Mid-Norway to Senegal,

European coast of the Mediterranean and west-

ern Black Sea.

Solea lascaris (RISSO 1810)

Figs. 778-779

syn. Solea pegusa YARELL 1829

syn. Solea aurantiaca GÜNTHER 1862

syn. Solea margaritifera GÜNTHER 1862

Investigated otoliths: 2 otoliths (left side) from

Plymouth, England, ZMH Ot.9.5.1995.25 (leg.

BMNH 1988.10.11.334) and BMNH 1988.10.11.334.

Discussion: Otoliths of S. lascaris are somewhat

more compressed than those of S. vulgaris due to

the deeper ventral rim and less rounded in out-

line than those of S. nasuta. A large series of oto-

liths of this species was also figured by CHAINE

(1936).

Distribution: Mediterranean, southern North

Sea and East-Atlantic from SW of Great Britain to

South Africa at depth from 30 to 350 m.

Solea nasuta (PALLAS 1811)

Figs. 780-781

Investigated otoliths: 2 otoliths (left and right

side) from the Black Sea off Rumania, ZMH Ot.

9.5.1995.26 (leg. BMNH 1964.12.7.3) and BMNH

1964.12.7.3.

Discussion: Very similar to S. lascaris but more

circular in outline. Probably very difficult to dis-

tinguish.

Figs. 778-779: Solea lascaris (RISSO 1810) – 10 ×

Figs. 780-781: Solea nasuta (PALLAS 1811) – 10 ×

778b

779a

778c

781

778a

780c

780a

780b

779b

300

Schwarzhans: Pleuronectiformes

Distribution: Black Sea and Mediterranean.

Solea kleini (RISSO 1810)

Fig. 785

syn. Synaptura savignyi KAUP 1858

syn. Solea capellonis STEINDACHNER 1868

Investigated otoliths: 1 somewhat eroded oto-

lith (left side) from Nice, southern France, BMNH

88.6.15.9.

Discussion: Otoliths compressed, similar to

S. lascaris and S. nasuta but always with some-

what crenulated rims and a less convex inner face.

A large series of otoliths of this species was also

figured by CHAINE (1936).

Distribution: Mediterranean and all along the

Atlantic coast of Africa to the tip of South Africa.

Dageichthys STAUCH & BLANC 1964

Type-species: Dageichthys lakdoensis STAUCH &

BLANC 1964

Remarks: Dageichthys is an endemic monospe-

cific freshwater genus exclusively recorded from

the Benue river basin in Cameroon. No specimen

of this rare species has been available for otolith

extraction.

Microbuglossus GÜNTHER 1862

Type-species: Solea humilis CANTOR 1850 (syn.

M. ovatus)

Diagnosis: Small, moderately thickset, com-

pressed otoliths with a roundish outline; ventral

and dorsal rims regularly curving, anterior and

posterior rims broadly rounded. Index l:h 1.10 to

1.25. Otoliths small, its size not much exceeding

3 mm.

Figs. 782-783: Solea vulgaris QUENSEL 1806 – 10 ×

Fig. 784: Solea aegyptiaca CHABANAUD 1927 – 10 ×

Fig. 785: Solea kleini (RISSO 1810) – 10 ×

782b

783a

782c

785a

782a

784c

784a

784b

783b

785b

301

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Sulcus somewhat deepened and moderately

wide, position median to slightly supramedian,

anteriorly reaching close to the anterior rim of

the otolith. Ostium usually not much wider than

cauda and also not much longer. Dorsal and ven-

tral depressions rather wide, somewhat deepened

and well connected around the cauda to form a

circumsulcal depression.

Inner face slightly convex, moderately

smooth; outer face almost flat, smooth. Rims

moderately thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

ovatus 1.10-1.15 3.1 1.55-1.75 1.0-1.2 3.0

heini 1.15-1.25 3.1 nm about 1.0 3.0

elongatus 1.15-1.25 2.5 1.4 1.0-1.3 3.0

Side dimorphism: Not apparent.

Variability: Details of the outline, which anyway

is not very characteristic, and certain proportions

of the sulcus are apt to some variations.

Discussion: The overall appearance of the oto-

liths of this ‘dwarfed’ genus is somewhat neo-

tenic, resembling juvenile specimens of Solea and

related genera. The main difference to otoliths of

the genus Solea is the complete absence of any

concavity at the posterior rim, but this character

could be lacking in very small specimens of that

genus as well. All in all, otoliths of Microbuglossus

will be difficult to be distinguished from juvenile

otoliths of other Soleidae if found isolated, par-

ticularly so as fossils. Because of the ‘neotenic’

appearance and the lack of a concavity at the

posterior rim I have decided to keep Microbuglos-

sus separate from Solea in contrast to most recent

citations in ichthyological literature.

Species and distribution: Three species from the

Indian Ocean – M. ovatus, M. heini and M. elonga-

tus.

Microbuglossus ovatus (RICHARDSON 1846)

Figs. 786-788

syn. Solea humilis CANTOR 1850

syn. Solea maculata BLEEKER 1851

Investigated otoliths: 3 otoliths (2 left side and

1 right side) from Singapore, ZMH Ot.14.5.1995.1-

2 (leg. BMNH 1984.1.12.83-86) and BMNH

1984.1.12.83-86.

Discussion: Very similar to M. heini, but may be

consistently somewhat more compressed.

Distribution: Coasts of India to Malaysia and

southern China.

Microbuglossus heini (STEINDACHNER 1902)

Figs. 789-791

Investigated otoliths: 3 otoliths (left side) from

Karachee, Pakistan, ZMH Ot.14.5.1995.3-4 (leg.

BMNH 1911.12.6.22-41) and BMNH 1911.12.6.22-

41.

Discussion: Very similar to M. ovatus (see above).

Colliculi in this species are completely fused.

Distribution: Coasts of the Arabian Peninsula

and Makran.

Microbuglossus elongatus (DAY 1877)

Figs. 792-794

Investigated otoliths: 3 otoliths (left side) from

the Persian Gulf, ZMH Ot.14.5.1995.5-6 (leg.

BMNH 1928.3.20.1-5) and BMNH 1928.3.20.1-5.

Discussion: Otoliths of M. elongatus are easily

recognized by their much more deepened sulcus.

Distribution: Persian Gulf and coasts of India

and Ceylon.

Vanstraelenia CHABANAUD 1950

Type-species: Vanstraelenia insignis CHABA-

NAUD 1950

Diagnosis: Moderately thickset to thickset, com-

pressed otoliths; ventral rim deeply and regular-

ly curving, deepest postventrally, dorsal rim near-

ly straight except for the more or less pronounced

predorsal projection, anterior rim ventrally round-

ed, dorsally joining the predorsal projection, pos-

terior rim blunt, nearly vertically cut, with faint

concavity. Index l:h 1.10 to 1.15. Otolith size up to

4 mm.

302

Schwarzhans: Pleuronectiformes

Sulcus somewhat deepened, variable in width,

position median to slightly supramedian, anteri-

orly reduced and not reaching very close to the

anterior rim of the otolith. Ostium wider than

cauda and somewhat longer. Dorsal and ventral

depressions rather wide, somewhat deepened and

well connected around the cauda to form a cir-

cumsulcal depression.

Inner face completely flat, not very smooth;

outer face markedly convex, smooth. Rims most-

ly thickset.

Measurements:

l:h h:t ol:cl oh:ch con.o

chirophthalma 1.10-1.15 2.7-2.9 1.4-1.5 1.1-1.2 2.6-3.0

insignis 1.10 2.0 1.9 1.7 1.6

Side dimorphism: Otoliths of the right side seem

to lack the faint concavity at the posterior rim.

Discussion: The otoliths of the two genera Van-

straelenia and Bathysolea form a morphologically

well defined subgroup within the Solea Group.

They are characterized by the completely flat

inner face and the anteriorly somewhat reduced

sulcus. In Bathysolea this character is further de-

veloped to form an undivided sulcus with fused

colliculi. It is assumed that these two genera rep-

resent a lineage endemic to the eastern Atlantic

which has originated from near such genera as

Microchirus with which it shares the most resem-

blance.

Species and distribution: Two species from the

tropical West African coast – V. chirophthalma and

V. insignis.

Figs. 786-788: Microbuglossus ovatus (RICHARDSON 1846) – 15 ×

Figs. 789-791: Microbuglossus heini (STEINDACHNER 1902) – 15 ×

Figs. 792-794: Microbuglossus elongatus (DAY 1877) – 15 ×

789b

788

787c

787a

786a

792c

792a

792b

786b

789a

794

793

791

790

303

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Vanstraelenia chirophthalma (REGAN 1915)

Figs. 795-796

Investigated otoliths: 2 otoliths (left and right

side) from off Lagos, Nigeria, ZMH Ot.14.5.1995.7

(leg. BMNH 1951.3.12.12) and BMNH 1951.3.

12.12.

Discussion: Otoliths of V. chirophthalma differ

from those of V. insignis in being more thin, show-

ing a less pronounced predorsal projection and a

narrower sulcus.

Distribution: Tropical coast of West Africa.

Vanstraelenia insignis CHABANAUD 1950

Fig. 797

Investigated otoliths: 2 otoliths (left side) from

off Nigeria, 4°01’N/7°56’E, BMNH 1962.6.18.125-

134.

Discussion: Otoliths of V. insignis are easily rec-

ognized by their much widened ostium, the very

thickset appearance and the pronounced predor-

sal projection.

V. insignis was regarded by DESOUTTER

(1994) as a synonym of V. chirophthalma. Otoliths,

however, seem to indicate that there might in-

deed be two recent species occurring simultane-

ously.

Distribution: Tropical coats of West Africa.

Bathysolea ROULE 1916

Type-species: Solea profundicola VAILLANT 1888

Diagnosis: Moderately thickset to thickset, com-

pressed otoliths with nearly round outline; all

rims regularly curving, ventral rim somewhat

deeper than dorsal rim. Index l:h 1.00 to 1.20.

Otolith size up to 3 mm, diagnostic maturity

reached at slightly above 1.0 mm.

Figs. 795-796: Vanstraelenia chirophthalma (REGAN 1915) – 10 ×

Fig. 797: Vanstraelenia insignis CHABANAUD 1950 – 10 ×

795b

795c

796a

795a

797c

797a

797b

796b

304

Schwarzhans: Pleuronectiformes

Sulcus rather shallow, short and narrow, po-

sition slightly supramedian, anteriorly not reach-

ing very close to the anterior rim of the otolith.

Ostium and cauda not differentiated and colliculi

completely fused. Dorsal and ventral depressions

rather wide, somewhat deepened and well con-

nected around the cauda to form a circumsulcal

depression.

Inner face almost completely flat, rather

smooth; outer face markedly convex, smooth.

Rims moderately thickset.

Measurements:

l:h h:t ol:cl oh:ch con.o

profundicola 1.20 2.4 nm nm 2.1

†polonica 1.00-1.15 2.6 nm nm 2.5-2.6

Side dimorphism: No data.

Discussion: In Bathysolea the sulcus morpholo-

gy is further reduced than in the related genus

Vanstraelenia. Ostium and cauda are completely

fused and so are its colliculi. The outline of the

otoliths is much more rounded. Bathysolea no

doubt represents the more apomorphic genus in

this little subgroup or lineage combining it with

Vanstraelenia.

Species and distribution: Two recent species from

the eastern Atlantic and the western Mediterra-

nean – B. profundicola and B. lactea – and one fossil

species from the Miocene of Poland – B. polonica.

Bathysolea profundicola (VAILLANT 1888)

Fig. 798

syn. Solea greenii GÜNTHER 1889

Investigated otoliths: 1 otolith (left side) from

51°50’N/11°51’W. BMNH 1987.1.21.906.

Discussion: This otolith is characterized by the

peculiar anteriorly narrowing sulcus.

799b

798c

799a

798a

799c

800a

798b

800b

801

Fig. 798: Bathysolea profundicola (VAILLANT 1888) – 15 ×

Figs. 799-801: Bathysolea polonica n.sp. – 15 ×

305

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Distribution: Rare, but widely distributed in the

eastern Atlantic from Ireland to Angola and in

the western Mediterranean from 200 to 1000 m.

The second recent species (B. lactea) is endemic to

the Cape Verde Islands off West Africa.

Bathysolea polonica n.sp.

Figs. 799-801

syn. genus Soleidarum sp. 2 – RADWANSKA

1992: pl. 38, figs. 4-6

Name: After Poland, the only area this species

so far has been recorded from.

Holotype: Fig. 799, ZPalUW Rak-445.

Type-Locality; Korytnica, southern Poland.

Age: Badenian, Middle Miocene.

Paratypes: 2 otoliths, topo- and stratitypic,

ZPalUW Rak-443 (fig. 800) and Rak-444 (fig. 801).

Diagnosis: Small, compressed otoliths with a

roundish outline, a nearly flat inner face and a

convex, smooth outer face. Ostium short and

narrow, with completely fused colliculi. Inner face

with irregularly distributed radial furrows.

Description: Outline: Otoliths small, to about

2 mm, with a compressed, nearly circular out-

line. Ventral rim somewhat deeper than dorsal

rim. Otoliths rather thickset.

Inner face: Almost completely flat and rather

smooth, except for some irregularly distributed

radial furrows. Sulcus short, narrow, beginning

at some distance from the anterior rim of the

otolith, rather shallow and with completely fused

colliculi. Circumsulcal depression wide and well

developed, but not very deep and with indistinct

outer margins.

Other views: Rims moderately sharp and

smooth. Outer face markedly convex and smooth.

Side dimorphism: Not apparent.

Ontogeny and Variability: The smallest otoliths

available is about 1.2 mm long (fig. 801) but does

not differ significantly from the largest one

(fig. 799) which is about 2.2 mm long.

Also variability seems to be rather restricted.

One specimen (fig. ) shows a somewhat more

deepened sulcus.

Discussion: B. polonica resembles well the recent

B. profundicola but is somewhat more compressed

and does not show that peculiar narrowing of the

sulcus anteriorly.

Distribution: Middle Miocene of Poland

7.8.4 Synaptura Group

Genera: Two genera – Austroglossus and Syn-

aptura.

Definition and relationship: The otoliths of the

two genera in the Synaptura Group are quite elon-

gate for soleids. Inner and outer faces are rather

flat, particularly in the horizontal direction,

whereas in the vertical direction the inner face

may be considerably convex. The cauda is short,

less than half the size of the ostium. In Synaptura

the ostium shows a tendency towards a bipartite

expression. That means, the anterior half of the

ostium is somewhat set apart from the posterior

half and deepened, thus giving the impression of

a sulcus divided into three more or less equally

long portions.

The elongate shape and the peculiar bipartite

ostium found in Synaptura has led me to separate

the Synaptura Group from the Solea Group from

which it most likely has originated as a special-

ized offshot. Austroglossus as the more plesiomor-

phic genus shows some relationship to such oto-

liths as Solea senegalensis (see respective entry).

Synaptura has also been often regarded as related

to Zebrias or Brachirus and other genera in the

Brachirus and Zebrias Groups. Otolith morpholo-

gy does not support such a supposed relation-

ship.

Austroglossus REGAN 1920

Type-species: Synaptura pectoralis KAUP 1858

syn. Pseudaustroglossus CHABANAUD 1937

(type-species: P. annectens; hybrid of A. micro-

lepis and Synaptura lusitanica)

Diagnosis: Rather thin, large and elongate oto-

liths; ventral rim moderately deep and regularly

curving, dorsal rim nearly straight, with pro-

nounced angles where it meets the anterior and

the posterior rims respectively, anterior rim

rounded, sometimes with notch above ostium,

306

Schwarzhans: Pleuronectiformes

posterior rim blunt, nearly vertically cut and

somewhat inclined ventrally. Index l:h 1.50 to 1.70.

Otolith size up to 6 mm.

Sulcus not much deepened and rather wide,

position slightly supramedian, anteriorly reach-

ing close to the anterior rim of the otolith. Ostium

not wider than cauda, but much longer. Dorsal

and ventral depressions rather wide, somewhat

deepened and well connected around the cauda

to form a circumsulcal depression.

Inner face slightly convex, the postventral

portion being somewhat bend outside, not very

smooth; outer face almost flat, smooth. Rims

mostly thin.

Measurements:

l:h h:t ol:cl oh:ch con.i

pectoralis 1.50-1.70 3.0 2.3-2.4 about 1.0 5-6

Side dimorphism: Not apparent.

Variability: Apparently very limited.

Discussion: Of the two genera in the Synaptura

Group Austroglossus is the more plesiomorphic

one and has not developed the bipartite ostium.

Also the straight dorsal rim and the nearly ver-

tically cut posterior rim are typical for this genus.

Species and distribution: Two species endemic

to the shores of southern Africa (Namibia and

Republic of South Africa) – A. pectoralis and A. mi-

crolepis. Otoliths of both species have recently been

figured in SMALE et al. (1995).

Austroglossus pectoralis (KAUP 1858)

Figs. 802-804

Investigated otoliths: 3 otoliths (2 left side and

1 right side) from Natal, South Africa, ZMH

Ot.14.5.1995.8-9 (leg. BMNH 1905.6.8.29-30) and

BMNH 1905.6.8.29-30.

Distribution: South Africa, from the Cape of

Good Hope to Natal.

Figs. 802-804: Austroglossus pectoralis (KAUP 1858) – 10 ×

802c

803a

802a

803c

804

803b

802b

307

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Synaptura CANTOR 1849

Type-species: Synaptura commersoniana CANTOR

1849

Diagnosis: Rather thin, moderately large and

elongate otoliths; ventral rim not very deep and

regularly curving, dorsal rim shallow, often with

pronounced angle where it meets the posterior

rim, sometimes developed as pointed spine, an-

terior rim more rounded, with angular ‘rostrum-

like’ tip at height of the sulcus, posterior rim blunt,

ventrally inclined. Index l:h 1.55 to 2.00. Otolith

size up to about 5.5 mm.

Sulcus usually deepened and rather wide,

position slightly supramedian, anteriorly reach-

ing close to the anterior rim of the otolith. Ostium

wider and much longer than cauda, bipartite with

the anterior half being deepened and the poste-

rior half being wider. Dorsal and ventral depres-

sions moderately wide, somewhat deepened and

well connected around the cauda to form a cir-

cumsulcal depression.

Inner face slightly convex, not very smooth;

outer face almost flat, rather smooth. Rims most-

ly sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

commersoniana 1.55-1.65 2.3-2.4 2.0-2.5 1.1-1.2 3.5-4.0

albomaculata 1.65 2.8 2.8 1.3 3.2

lusitanica 1.85-2.00 2.0-2.8 2.0-2.2 1.35-1.5 3.0-4.0

Side dimorphism: Otoliths of the left side seem

to have a slightly more convex inner face and the

postventral area is more gently curving.

Ontogeny and variability: Smaller otoliths are

more gently curving in outline (see figures in

CHAINE, 1937).

Variability as it seems is very restricted.

Discussion: Otoliths of the genus Synaptura are

easily recognized by their elongate shape and the

bipartite ostium. Both characters are least devel-

oped in S. commersoniana which is probably the

most plesiomorphic species in this genus.

Species and distribution: Five nominally valid

species – S. commersoniana and S. albomaculata from

the Indian Ocean, S. marginata from South Africa,

S. cadenati from West Africa and S. lusitanica along

the coasts of West Africa and Portugal.

Synaptura commersoniana CANTOR 1849

Figs. 805-806

syn. Solea russellii BLEEKER 1852

Investigated otoliths: 2 otoliths (left and right

side) from Karachee, Pakistan, ZMH Ot.14.5.

1995.10 (leg. BMNH 1911.12.6.19-21) and BMNH

1911.12.6.19-21.

Figs. 805-806: Synaptura commersoniana CANTOR 1849 – 15 ×

Fig. 807: Synaptura albomaculata (KAUP 1858) – 15 ×

807c

806a

805a

807b

807a

806b

805b

308

Schwarzhans: Pleuronectiformes

Discussion: The otoliths of S. commersoniana ex-

hibit the most plesiomorphic pattern of the spe-

cies in this genus with only an incipient bipartite

ostium and a rather low index l:h.

Distribution: Eastern Atlantic from Portugal to

the Congo river mouth and in the western Med-

iterranean.

Synaptura albomaculata (KAUP 1858)

Fig. 807

Investigated otoliths: 1 otolith (left side) from

southern India, BMNH 1969.3.27.1-2.

Discussion: In this species the ostium is distinctly

bipartite. It differs from S. lustanica by the lower

index l:h and the lack of a postdorsal spine.

Distribution: Indian Ocean from Oman to Sin-

gapore.

Synaptura lusitanica CAPELLO 1868

Figs. 808-811

syn. Synaptura punctatissima PETERS 1877

Investigated otoliths: 4 otoliths (2 left side and

2 right side) from Senegal, IRSNB (coll. Nolf).

Discussion: Like S. albomaculata otoliths of

S. lusitanica show a distinctly bipartite ostium, but

they are more elongate and with a sharp postdor-

sal spine.

Distribution: Eastern Atlantic from Portugal to

the river Congo mouth and western Mediterra-

nean.

Figs. 808-811: Synaptura lusitanica CAPELLO 1868 – 10 ×

808c

809a

808a

809b

810

808d

808b

811a

811b

309

Piscium Catalogus, Part Otolithi piscium, Vol. 2

7.8.5 Brachirus Group

Genera: Four genera – Heterobuglossus, Dexillich-

thys, Brachirus, Anisochirus and Phyllichthys.

Definition and relationship: The otoliths of the

five genera in the Brachirus Group are morpho-

logically intermediate between those of the Solea

Group, from which they have derived most like-

ly, and the apomorphic Zebrias Group. Its com-

bine may not be entirely natural. The two more

plesiomorphic genera – Heterobuglossus and Dexil-

lichthys – could also be placed in the Solea Group,

Brachirus, Anisochirus and Phyllichthys could be

regarded as the most ‘primitive’ members of the

Zebrias Group.

The common character found in the members

of this group is an expansion of the postventral

portion, a rather shallow ventral rim and a re-

duction of the postdorsal portion (at least in most

species). This is even more so developed in the

genera of the Zebrias Group. Unlike in otoliths of

the Zebrias Group, however, the sulcus is not re-

duced anteriorly and neither are the colliculi

fused. All in all, otoliths of the Brachirus and the

Zebrias Groups often look like being placed up-

side down.

Heterobuglossus CHABANAUD 1931

Type-species: Synaptura aspilos BLEEKER 1851

Diagnosis: Moderately thickset, compressed oto-

liths with rounded rectangular outline; ventral

and dorsal rims regularly curving but shallow,

somewhat undulating, anterior rim broadly

rounded or blunt, posterior rim blunt, slightly

concave, postventral and postdorsal projections

nearly equal in expression. Index l:h 1.00 to 1.15.

Otolith size up to nearly 3 mm.

Sulcus somewhat deepened and rather nar-

row, position slightly supramedian, anteriorly

reaching close to the anterior rim of the otolith.

Ostium not wider than cauda, but much longer.

Dorsal and ventral depressions moderately wide,

somewhat deepened and well connected around

the cauda to form a circumsulcal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims moderately sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

aspilos 1.00-1.15 3.0 1.4-1.8 0.95-1.1 2.6

Side dimorphism: Not apparent.

Variability: Variability in this genus seemingly

is restricted to minor variations of the outline and

the sulcus proportions.

Discussion: Heterobuglossus is the most plesio-

morphic genus in this group and could also be

regarded as a member of the Solea Group. Char-

acteristic is its rounded rectangular outline and

the rather shallow ventral rim.

Species and distribution: Heterobuglossus is a

monospecific genus with H. aspilos distributed

from Malaysia through Indonesia to northern

Australia.

Heterobuglossus aspilos (BLEEKER 1851)

Figs. 812-814

syn. Synaptura marmorata BLEEKER 1853

syn. Synaptura heterolepis BLEEKER 1856

Investigated otoliths: 3 otoliths (2 left side and

1 right side) from Singapore, ZMH Ot.

14.5.1995.11-12 (leg. BMNH 1933.7.31.21-22) and

BMNH 1933.7.31.21-22.

Dexillichthys (WHITLEY 1931)

Type-species: Synaptura macrolepis BLEEKER

1958

syn. Dexillus CHABANAUD 1930 (pre-occupied;

type-species: S. macrolepis)

syn. Whitleyia CHABANAUD 1930 (pre-occu-

pied; type-species: Synaptura setifer)

syn. Paradicula WHITLEY 1931 (type-species:

Synaptura setifer)

syn. Strandichthys WHITLEY 1937 (type-species:

Synaptura muelleri)

syn. Mischommatus CHABANAUD 1938 (type-

species: Synaptura muelleri)

Diagnosis: Moderately thickset, compressed oto-

liths; ventral rim moderately deep, deepest pos-

teriorly, dorsal rim more shallow, somewhat un-

dulating, anterior rim rounded, posterior rim

310

Schwarzhans: Pleuronectiformes

blunt, nearly vertically cut, postventral projec-

tion more pronounced than angular postdorsal

projection. Index l:h 1.25. Otolith size up to about

4 mm.

Sulcus very shallow and narrow, position

nearly median, anteriorly somewhat reduced and

not reaching very close to the anterior rim of the

otolith. Ostium slightly wider than cauda and

much longer. Dorsal and ventral depressions rath-

er wide, with indistinct outer margins, somewhat

deepened and well connected around the cauda

to form a circumsulcal depression.

Inner face nearly flat, not very smooth; outer

face almost flat, centrally concave and rather

smooth. Rims mostly thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

macrolepis 1.25 2.6 2.9 1.4 about 10

Side dimorphism: No data.

Discussion: Dexillichthys is only tentatively

placed in this group. The otoliths are character-

ized by the nearly flat inner face with the very

shallow sulcus, the extremely small cauda and

the anteriorly reduced ostial opening.

Species and distribution: Three species from the

Indonesian Archipelago, the Philippines and

northern Australia – D. macrolepis, D. muelleri and

D. setifer.

Dexillichthys macrolepis (BLEEKER 1858)

Fig. 815

Investigated otoliths: 1 otolith (left side) from

the Kumai river, SW Borneo, BMNH 1933.3.11-11a.

Distribution: The Gulf of Bengal and Borneo.

Brachirus SWAINSON 1839

Type-species: Pleuronectes orientalis BLOCH &

SCHNEIDER 1801

syn. Achiroides BLEEKER 1851 (type-species: Pla-

gusia melanorhynchus)

syn. Euryglossa KAUP 1858 (type-species: Pleu-

ronectes orientalis)

syn. Eurypleura KAUP 1858 (type-species: Plagu-

sia melanorhynchus)

syn. Barbourichthys CHABANAUD 1933 (type-

species: Barbourichthys zanzibaricus)

Figs. 812-814: Heterobuglossus aspilos (BLEEKER 1851) – 15 ×

812c

812a

812d

814

813

812b

311

Piscium Catalogus, Part Otolithi piscium, Vol. 2

syn. Trichobrachirus CHABANAUD 1943 (type-

species: Synaptura villosa)

syn. Achlyopa WHITLEY 1947 (type-species: Syn-

aptura nigra)

Diagnosis: Thin to moderately thickset, com-

pressed otoliths; ventral rim shallow, regularly

curving, postventral projection usually well de-

veloped, dorsal rim less shallow, sometimes with

postdorsal angle, anterior rim broadly rounded,

posterior rim blunt, cut, ventrally or (less com-

mon) dorsally inclined. Index l:h 1.05 to 1.30.

Otolith size up to about 3 mm, diagnostic matu-

rity probably reached early at about 1.2 to 1.5 mm.

Sulcus moderately deep and moderately wide,

position more or less median, anteriorly reaching

close to the anterior rim of the otolith. Ostium

slightly wider than cauda, but much longer. Dor-

sal and ventral depressions not very wide, slight-

ly deepened and well connected around the cau-

da to form a circumsulcal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth or slightly ornamented.

Rims mostly sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

orientalis 1.10 3.4-3.8 1.9-2.6 1.2-1.3 2.6-2.8

niger 1.15 nd 1.8-2.0 1.1-1.2 nd

cinerascens 1.20-1.30 3.0 1.8-2.0 1.2-1.3 3.0

pan 1.05 2.4 1.6 1.2 3.0

melanorhynchus 1.25 nd 2.0 1.3 nd

Side dimorphism: Otoliths of the right side may

have a slightly stronger convex inner face than

those of the left side.

Ontogeny and variability: In B. cinerascens small-

er otoliths are slightly more compressed than

larger ones.

The level of variations is rather moderate,

except for the index ol:cl which seems to variate

quite considerably.

Discussion: Most species of the genus Brachirus

show the ventrally inclined posterior rim and a

tendency to fuse the colliculi. These characters

are further developed in the Zebrias Group and in

fact Brachirus could also be regarded as the most

‘primitive’ member of that group. More interme-

diate even are ovally shaped otoliths of the relat-

ed genera Anisochirus and Phyllichthys (see respec-

tive entries). Most members of the Zebrias Group

show completely fused colliculi and except for

the genus Aesopia, a somewhat reduced sulcus

opening.

Species and distribution: Brachirus is a species

rich genus in the Indo-West-Pacific, but appar-

ently in need of revision. The following list of

nominally valid species thus may not be com-

plete – B. annularis, B. breviceps, B. cinerascens,

B. melanorhynchus, B. orientalis, B. nigra, B. pan,

B. salinarum, B. selheimi, B. villosa, B. zanzibarica.

B. panoides is tentatively being excluded from the

genus and placed in a genus of its own – Aniso-

chirus (see respective entry). Many species of Bra-

chirus are known to invade upstream into rivers,

some are exclusively freshwater.

Brachirus orientalis

(BLOCH & SCHNEIDER 1801)

Figs. 816-817

syn. Solea foliacea RICHARDSON 1840

syn. Solea trichodactylus KAUP 1858

syn. Brachirus sundaicus BLEEKER 1866

Fig. 815: Dexillichthys macrolepis (BLEEKER 1858) – 10 ×

312

Schwarzhans: Pleuronectiformes

Investigated otoliths: 2 otoliths (left and right

side) from off Pakistan, IRSNB (coll. Nolf).

Discussion: A species with the typical outline of

otoliths of the Brachirus Group. The otoliths are

relatively compressed and the sulcus is rather

narrow.

Distribution: Makran Coast, Pakistan, to China.

Brachirus niger (MACLEAY 1881)

Figs. 818-819

Investigated otoliths: 2 otoliths (left and right

side) from off Sydney, Australia, ZMH Ot.20.5.

1995.1 (leg. BMNH 1890.9.23.226-8) and BMNH

1890.9.23.226-8.

Discussion: This species is remarkable for its

pronounced postdorsal angle.

Distribution: Coasts of northern Australia.

Figs. 816-817: Brachirus orientalis (BLOCH & SCHNEIDER 1801) – 10 ×

Figs. 818-819: Brachirus niger (MACLEAY 1881) – 15 ×

816b

816a

817c

817b

818

817b

819

313

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Brachirus cinerascens GÜNTHER 1862

Figs. 820-822

Investigated otoliths: 3 otoliths (left side) from

Basra, Iraq, ZMH Ot.20.5.1995.2-3 (leg. BMNH

1920.3.3.290-6) and BMNH 1920.3.3.290-6.

Discussion: Similar to B. orientalis and often re-

garded as synonymous, but otoliths more elon-

gate and delicately ornamented.

Distribution: Persian Gulf; also recorded from

Ceylon.

Brachirus pan

(HAMILTON-BUCHANAN 1822)

Fig. 823

Investigated otoliths: 1 otolith (left side) from

the Sunderabands, Bangla Desh, BMNH

1928.3.20. 15-17.

Discussion: Otoliths compressed with a rather

flat inner face and a very wide sulcus.

Distribution: Coasts of eastern India and Ma-

laysia; entering rivers.

Brachirus melanorhynchus (BLEEKER 1850)

Fig. 824

syn. Achiroides leucorhynchus BLEEKER 1851

syn. Solea harmandi SAUVAGE 1878

Investigated otoliths: 1 somewhat eroded, prob-

ably juvenile otolith (right side) from Singapore,

BMNH 1984.1.18.263.

Discussion: Judging from the poorly preserved

and small, probably juvenile specimen available,

it is an otolith with a strong postdorsal angle and

a wide sulcus.

Distribution: Freshwater of Malaysia, Indochi-

na, Java, Sumatra and Borneo.

Anisochirus GÜNTHER 1862

Type-species: Synaptura panoides BLEEKER 1851

syn. Chabanaudetta WHITLEY 1931 (unneeded

substitute for Anisochirus)

Diagnosis: Rather thin, oval otoliths; ventral rim

shallow and regularly curving, dorsal rim some-

what reduced, also rather shallow, anterior rim

rounded, posterior rim too, but more broadly so.

Index l:h about 1.3. Otolith size small, not much

exceeding 2 mm.

Sulcus moderately deep, rather narrow and

short, terminating at some distance from the

posterior tip of the otolith, position slightly su-

pramedian, anteriorly reaching close to the ante-

rior rim of the otolith. Ostium slightly wider than

cauda, but much longer. Colliculi separated.

Dorsal and ventral depressions rather narrow,

somewhat deepened and well connected around

the cauda to form a circumsulcal depression.

Inner face convex, smooth; outer face almost

flat, smooth or slightly ornamented. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

panoides about 1.3 nm 1.8 0.95 nm

Side dimorphism: No data.

Discussion: I have selected to keep this mono-

specific genus separate from Brachirus, where it

is usually placed, because of its intermediate oto-

lith morphology between Brachirus and Phyllich-

thys. From the letter it merely differs in the more

clearly separated colliculi. The short sulcus and

the oval outline relate it to Phyllichthys.

Species and distribution: Anisochirus presuma-

bly is a monospecific genus with A. panoides

known from the Indo-Malaysian Archipelago.

Anisochirus panoides (BLEEKER 1851)

Fig. 825

Investigated otoliths: 1 otolith, eroded along the

dorsal rim (left side) from Bangkok, BMNH

1928.5.22.1.

Discussion: Judging from the somewhat eroded

otolith available A. panoides similar to P. puncta-

314

Schwarzhans: Pleuronectiformes

tus (see below), but with more clearly separated

colliculi.

Distribution: Indochina, Sumatra and Borneo,

entering freshwater.

Phyllichthys MCCULLOCH 1916

Type-species: Synaptura sclerolepis MACLEAY

1878

Diagnosis: Rather thin, oval otoliths; ventral rim

shallow and regularly curving, dorsal rim some-

what reduced, also rather shallow, anterior rim

rounded, posterior rim too, but more broadly so.

Index l:h 1.45. Otolith size small, not much ex-

ceeding 2 mm.

Sulcus moderately deep, rather narrow and

short, terminating at some distance from the

posterior tip of the otolith, position slightly su-

pramedian, anteriorly reaching close to the ante-

rior rim of the otolith. Ostium slightly wider than

cauda, but much longer. Ostium nearly fused with

cauda. Dorsal and ventral depressions rather

narrow, somewhat deepened and well connected

around the cauda to form a circumsulcal depres-

sion.

Inner face convex, smooth; outer face almost

flat, smooth or slightly ornamented. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

punctatus 1.45 nm 2.6 1.2 nm

Side dimorphism: No data.

Discussion: CHABANAUD (1939) placed Phyl-

lichthys close to Zebrias (see Zebrias Group). Their

otoliths morphologically perfectly close the gap

between the genera of the Brachirus and the Ze-

brias Group. Phyllichthys is particularly close to

Anisochirus (see above). The ventrally pronounced

outline of the otolith and the short sulcus resem-

ble otoliths of the Zebrias Group, whereas the faint

separation of the colliculi and the close approach

of the sulcus to the anterior rim is similar to other

genera in the Brachirus Group. Phyllichthys (and

also Anisochirus) thus could also be regarded as

the most plesiomorphic genus of the Zebrias

Group.

Species and distribution: CHABANAUD (1939)

listed three species from the warm waters of

Australia – P. sclerolepis, P. punctatus and P. sejunc-

tus.

Figs. 820-822: Brachirus cinerascens GÜNTHER 1862 – 10 ×

Fig. 823: Brachirus pan (HAMILTON-BUCHANAN 1922) – 15 ×

Fig. 824: Brachirus melanorhynchus (BLEEKER 1850) – 15 ×

823b

820a

820c

820b

822

823b

821

824

823a

315

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Phyllichthys punctatus MCCULLOCH 1916

Fig. 826

Investigated otoliths: 2 otoliths, somewhat erod-

ed by formalin (left and right side) from Western

Australia, off Singletown Beach, 32°27’S/

115°45’E, ZMH Ot.20.5.1995.4-5 (leg. WAM-P

28397-003).

Distribution: Western Australia.

7.8.6 Zebrias Group

Genera: This group contains at least 5 recent

genera – Aesopia, Pseudaesopia, Soleichthys, Zebrias

and Typhlachirus. Except for the latter, otoliths are

known from all of these. Recommendation is

made to separate the two species of the genus

Soleichthys and erect a new genus for Soleichthys

microcephalus should other ichthyological inves-

tigations support the otolith analysis. Phyllichthys

and Anisochirus of the Brachirus Group could also

be placed in this group (see respective entries).

Finally, one newly erected fossil genus – Granu-

lithus – is also included in this group. The ending

-lithus is chosen to indicate that it represents an

otolith based genus.

Definition and relationship: The otoliths of this

group of fishes, which are often found in near

coralline environments, are characterized by oto-

liths with a set of synapomorphic features. These

are the ventrally pronounced outline and the deep

sulcus with completely fused colliculi (except for

“Soleichthys” microcephalus). Also the sulcus is

rather short, terminating at some distance from

the posterior rim and also from the anterior rim

of the otolith (except for Aesopia and Granulithus).

The Zebrias Group clearly represents a spe-

cialized offshot from the Brachirus Group. A

morphologically intermediate genus as far as

otoliths are concerned is Phyllichthys. Phyllichthys

is placed here in the Brachirus Group (see respec-

tive entry) but could also be regarded as the most

plesiomorphic genus of the Zebrias Group.

Aesopia KAUP 1858

Type-species: Aesopia cornuta KAUP 1858

syn. Coryphaesopia CHABANAUD 1930 (type-

species: A. cornuta)

Diagnosis: Moderately thin, rather elongate and

ovally shaped otoliths; ventral rim shallow, broad,

dorsal rim more rounded, short, without angles,

anterior and posterior rims rounded. The otolith

looks like turned upside down. Index l:h 1.55 to

1.65. Otolith size small, not exceeding much

2.5 mm.

Sulcus deepened, wide, anteriorly reaching

relatively close to the anterior rim of the otolith,

posteriorly terminating at some distance from the

posterior rim of the otolith. Ostium and cauda

completely fused, and so are the colliculi. Dorsal

and ventral depressions rather narrow, somewhat

deepened and well connected around the cauda

to form a circumsulcal depression.

Inner face slightly convex, not very smooth;

outer face almost flat, smooth. Rims moderately

thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

cornuta 1.55-1.65 2.5-2.7 – – 3.5-4.2

Side dimorphism: Not apparent.

Variability: Details of the outline and the width

of the sulcus seem to variate slightly.

Discussion: Otoliths of Aesopia differ somewhat

from those of the other genera in the Zebrias

Group. They are rather elongate and, most im-

portant, the sulcus still reaches close to the ante-

rior tip of the otolith.

Species and distribution: Aesopia is a monospe-

cific genus with A. cornuta widely distributed

through the Indo-West Pacific.

Fig. 825: Anisochirus panoides (BLEEKER 1851) – 15 ×

Fig. 826: Phyllichthys punctatus MCCULLOCH 1916

– 15 ×

826

825

316

Schwarzhans: Pleuronectiformes

Aesopia cornuta KAUP 1858

Figs. 827-829

syn. Coryphaesopia barnardi CHABANAUD 1934

Investigated otoliths: 3 otoliths (2 left and 1 right

side) from the Ganjam coast, India, ZMH

Ot.20.5.1995.6-7 (leg. BMNH 90.12.4.10-11) and

BMNH 90.12.4.10-11.

Distribution: South Africa through the Indian

Ocean to the West Pacific (Japan).

†Granulithus n.gen.

Type-species: Aesopia granum SCHWARZHANS

1994.

Name: By tautonomy from the type-species; end-

ing -lithus indicates it being an otolith based fos-

sil genus.

Diagnosis: A fossil, otolith based genus of the

family Soleidae, subfamily Soleinae, Zebrias oto-

lith group with the following characters. The oto-

liths are very small, not exceeding 1.5 mm, com-

pact and rather thickset. Outline is moderately

elongate, ovally, somewhat variable. Sulcus mod-

erately wide to wide, very deep, with completely

fused colliculi, short, terminating at some dis-

tance from the posterior rim of the otolith, but

anteriorly reaching relatively close to the anteri-

or tip of the otolith. Circumsulcal depression

narrow, rather shallow, but well developed

around caudal tip of sulcus. Inner and outer fac-

es moderately convex and smooth. Rims rather

thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

†granum 1.40-1.80 2.2-2.4 – – 3.2-3.8

Side dimorphism: Not apparent.

Variability: Outline and width of the sulcus are

quite variable.

Discussion: Granulithus is quite similar to Aeso-

pia in which it has originally been placed. It is in

particular the deep sulcus, which closely reaches

to the anterior tip of the otolith which both gen-

era share. However, the compact appearance and

the extremely deepened sulcus are quite distinc-

tive and represent the main reasons to separate

the fossil from the recent genus.

Species and distribution: Granulithus is a mon-

ospecific genus with G. granum exclusively known

from the Upper Oligocene of northern Germany.

There it occurs in a near shore rocky subtidal pool

environment.

Granulithus granum (SCHWARZHANS 1994)

Figs. 830-833

syn. Aesopia granum SCHWARZHANS 1994 –

SCHWARZHANS 1994: figs. 529-532

Investigated otoliths: 4 otoliths (1 left, 3 right

side) including the holotype (fig. 830) and the

paratypes (figs. 831-833) from the Upper Oli-

gocene of Ratingen near Düsseldorf, northern

Germany.

Distribution: Upper Oligocene of northern Ger-

many, known only from the type-locality.

Figs. 827-829: Aesopia cornuta KAUP 1858 – 15 ×

829b

827a

827c

827b

828

829a

317

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Soleichthys BLEEKER 1860

Type-species: Solea heterorhinos BLEEKER 1856

Diagnosis: Moderately thin, compressed, ovally

shaped otoliths; ventral rim shallow, broad, dor-

sal rim more rounded, short, without angles,

anterior rim rounded, posterior rim blunt or

rounded. All rims somewhat undulating. The

otolith looks like turned upside down. Index l:h

about 1.30. Otolith size rather small, probably not

exceeding much 3 mm.

Sulcus deepened, wide, anteriorly reduced,

posteriorly terminating at some distance from the

posterior rim of the otolith. Ostium and cauda

completely fused, and so are the colliculi. Dorsal

and ventral depressions moderately wide, some-

what deepened and well connected around the

cauda to form a circumsulcal depression.

Inner face convex, not very smooth; outer face

almost flat, smooth. Rims sharp to moderately

thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

microcephalus 1.10-1.15 2.9 1.5-1.6 1.05-1.20 3.0

heterorhinos 1.30 3.5 – – 2.7

Side dimorphism: Not apparent in S. heterorhi-

nos. In “S.” microcephalus otoliths of the left side

show separated colliculi, whereas in otoliths of

the right side they are practically fused.

Variability: Apparently very limited.

Discussion: Otoliths of S. heterorhinos resemble

those of the genus Aesopia in outline and general

appearance. However, the sulcus is anteriorly

reduced and the otolith itself more compressed. –

“S”. microcephalus resembles more otoliths of

Pseudaesopia in its more rectangular outline. A very

plesiomorphic character for a member of the

Zebrias Group found in this species is the separa-

tion of the colliculi (particularly so in otoliths of

the left side). All in all, otoliths of “S”. microcepha-

lus differ significantly from the type-species of

Soleichthys – S. heterorhinos – and it is because of

that that I suggest to place it in a separate genus

altogether, provided other ichthyological analy-

ses support the otolith findings. “S”. microcepha-

lus seemingly represents one of the most plesio-

morphic species in the Zebrias Group character-

ized by its separated colliculi. It has probably

given rise to the genera Pseudaesopia and Zebrias.

Species and distribution: Traditionally, two spe-

cies have been placed in this genus – S. heterorhi-

nos widely distributed throughout the Indo-West

Pacific and “S”. microcephalus from southern

Australia. Recently, S. siammakuti has been de-

scribed from the Gulf of Thailand.

Soleichthys heterorhinos (BLEEKER 1856)

Fig. 834

syn. Aesopia multifasciata KAUP 1858

syn. Solea nigrostriolata STEINDACHNER &

KNER 1870

syn. Solea tubifera PETERS 1876

syn. Solea lineata RAMSAY 1883

?syn. Solea borbonica REGAN 1905

Investigated otoliths: 1 otolith (left side) from

the Oualau atoll, BMNH 79.5.14.65.

Discussion: See entry to genus.

Distribution: Indo-West Pacific from the Isle of

Mauritius to Australia and the Philippines.

Figs. 830-833: Granulithus granum (SCHWARZHANS 1994) – 15 ×

832b

830a

830c

830b

831

832a

833

318

Schwarzhans: Pleuronectiformes

“Soleichthys” microcephalus GÜNTHER 1862

Figs. 835-837

Investigated otoliths: 3 otoliths (2 left side, figs.

835, 837 and 1 right side, fig. 836) from Port Jack-

son, Australia, ZMH Ot.20.5.1995.8-9 (leg. BMNH

90.9.23.56-60) and BMNH 90.9.23.56-60.

Discussion: See entry to genus.

Distribution: Coasts of southern temperate Aus-

tralia.

Pseudaesopia CHABANAUD 1934

Type-species: Aesopia regani GILCHRIST 1906

Diagnosis: Moderately thin, compressed otoliths

with rounded rectangular outline; ventral rim

shallow, broad, dorsal rim more rounded, short,

with rounded medio- and postdorsal angles, ante-

rior rim rounded, posterior rim blunt, high, near-

ly vertically cut. The otolith looks like turned

upside down. Index l:h 1.15 to 1.30. Otolith size

small, not exceeding much 2.5 mm.

Sulcus deepened, wide, anteriorly reduced,

posteriorly terminating at some distance from the

posterior rim of the otolith. Ostium and cauda

completely fused, and so are the colliculi. Dorsal

and ventral depressions rather narrow, somewhat

deepened and well connected around the cauda

to form a circumsulcal depression.

Inner face convex, not very smooth; outer face

almost flat, smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

japonica 1.15-1.30 3.0 – – 2.3

Side dimorphism: Not apparent.

Variability: Except for the proportions of the

otolith intraspecific variability seems to be very

limited.

Fig. 834: Soleichthys heterorhinus (BLEEKER 1856) – 15 ×

Figs. 835-837: “Soleichthys” microcephalus GÜNTHER 1862 – 15 ×

835a

835c

837

835b

836

319

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: Otoliths of the genus Pseudaesopia

very closely resemble those of the genera Zebrias

and Soleichthys. In fact, similarity with Zebrias is

so close that based on otoliths Pseudaesopia would

better be regarded as a subgenus only. Within the

genus Soleichthys “S”. microcephalus is closest,

merely differing in the separation of the colliculi

(see respective entry for further discussion).

Species and distribution: Pseudaesopia contains

three species – P. regani from South Africa, P. ja-

ponica from Japan and P. crossolepis from China.

Pseudaesopia japonica (BLEEKER 1860)

Figs. 838-841

syn. Zebrias smithii SMITH & POPE 1906

Investigated otoliths: 4 otoliths (3 left and 1 right

side) from the Inland Sea of Japan, ZMH

Ot.20.5.1995.10-12 (leg. BMNH 1905.6.6.213-222)

and BMNH 1905.6.6.213-222.

Distribution: Japan.

Zebrias JORDAN & SNYDER 1900

Type-species: Pleuronectes zebra BLOCH 1785

syn. Holonodus CHABANAUD 1936 (type-spe-

cies: Synaptura synapturoides)

syn. Haplozebrias CHABANAUD 1943 (type-spe-

cies: Synaptura fasciata)

syn. Nematozebrias CHABANAUD 1943 (type-

species: Aesopia quagga)

syn. Strabozebrias CHABANAUD 1943 (type-spe-

cies: Synaptura cancellata)

Diagnosis: Thin to moderately thickset, com-

pressed otoliths with rounded rectangular out-

line; ventral rim shallow, broad, dorsal rim more

rounded, with rounded pre- and postdorsal an-

gles, anterior and posterior rims blunt, high, near-

ly vertically cut. The otolith looks like turned

upside down. Index l:h 1.15 to 1.30. Otolith size

moderate, not exceeding much 3.5 mm.

Sulcus deepened, narrow or wide, very short,

anteriorly reduced, posteriorly terminating at

some distance from the posterior rim of the oto-

lith. Ostium and cauda completely fused, and so

are the colliculi. Dorsal and ventral depressions

moderately wide, somewhat deepened and well

connected around the cauda to form a circumsul-

cal depression.

Inner face convex, not very smooth; outer face

almost flat, smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

altipinnis 1.25 3.0 – – 3.3

synapturoides 1.05-1.10 3.1 – – 2.6

cancellatus 1.20-1.30 3.5 – – 3.0

zebrias 1.30 4.0 – – 4.5

quagga 1.20-1.25 nm – – nm

Figs. 838-841: Pseudaesopia japonica (BLEEKER 1860) – 15 ×

838a

838c

840

838b

839

841

320

Schwarzhans: Pleuronectiformes

Side dimorphism: Otoliths of the left side usu-

ally show a wider sulcus than those of the right

side. Also sometimes left hand otoliths exhibit an

incipient separation into ostium and cauda (al-

though colliculi are always fused) or sometimes

are slightly more compressed than those of the

right side.

Discussion: Zebrias has been separated into var-

ious genera or subgenera depending on the au-

thors views. At this stage the mosaic pattern of

the otolith morphology does not support such a

concept. Nevertheless, it seems that two slightly

different morphologies could possibly be distin-

guished and could eventually be attributed to two

separate genera or subgenera.

At first, there is a group of species with oto-

liths nearly rectangular in outline containing

Z. altipinnis, Z. synapturoides and Z. cancellatus.

Those closely resemble Pseudaesopia and may even

be placed in that genus. But also “Soleichthys”

microcephalus is very similar except for the sepa-

rated colliculi in that species.

The second group shows anteriorly narrowed

otoliths which are rather thin and have a more

flat inner face. This species group contains Z. zebra

and Z. quagga.

Species and distribution: Zebrias contains about

14 nominally valid species mostly from the Indi-

an Ocean – Z. altipinnis, Z. annadalei, Z.cancellatus,

Z. cochinensis, Z. craticulus, Z. fasciatus, Z. keralen-

sis, Z. lucapensis, , Z. munroi, Z. penescalaris, Z. quag-

ga, Z. scalaris, Z. synapturoides and Z. zebra.

Zebrias altipinnis (ALCOCK 1890)

Figs. 842-843

Investigated otoliths: 2 otoliths (1 left and 1 right

side) from the river Hughli, India, ZMH Ot.20.5.

1995.13 (leg. BMNH 1928.3.20.29-30) and BMNH

1928.3.20.29-30.

Discussion: This species is remarkable for the

incipient distinction into ostium and cauda in

otoliths of the left side. In this respect it resem-

bles “Soleichthys” microcephalus, although there

even the colliculi are separated. Otolith morphol-

ogy suggests that Z. altipinnis probably is the most

plesiomorphic species in the genus.

Distribution: India and Malaysia.

Figs. 842-843: Zebrias altipinnis (ALCOCK 1890) – 15 ×

842a

842c

842b

843

321

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Zebrias synapturoides (JENKINS 1910)

Figs. 844-845

syn. Solea jerreus CUVIER 1829

Investigated otoliths: 2 otoliths (left and right

side) from the Ganjam coast, India, ZMH Ot.20.5.

1995.14 (leg. BMNH 1928.3.20.23-25) and BMNH

1928.3.20.23-25.

Discussion: Otoliths of Z. synapturoides are very

compressed and those of the left side show an

extremely widened sulcus.

Distribution: India.

Zebrias cancellatus MCCULLOCH 1916

Figs. 846-847

Investigated otoliths: 2 otoliths (left and right

side) from Shark Bay, Western Australia, 25°21’S/

113°44’E, ZMH Ot.20.5.1995.15-16 (leg. WAM-P

28624-001).

Discussion: Similar to Z. synapturoides, but more

elongate and with a very regular rectangular

outline.

Distribution: Western Australia.

Zebrias zebra (BLOCH 1785)

Fig. 848

syn. Solea ommatura RICHARDSON 1845

Investigated otoliths: 1 otolith (left side), with-

out location, BMNH 74.1.16.39.

Discussion: Otoliths of Z. zebra are readily rec-

ognized by its anteriorly narrowed outline.

Distribution: Widely distributed from Indone-

sia to China and Japan.

Zebrias quagga (ALCOCK 1890)

Figs. 849-850

Investigated otoliths: 2 somewhat eroded, juve-

nile otoliths (left side) from the Persian Gulf,

BMNH 1911.2.23.53-57.

Discussion: The otoliths available from Z. quagga

are too small and poorly preserved to allow reli-

able analysis. It seems that they are basically sim-

ilar to Z. zebrias.

Distribution: Widely distributed from the Per-

sian Gulf to China and the Sea of Java.

Figs. 844-845: Zebrias synapturoides (JENKINS 1910) – 15 ×

Figs. 846-847: Zebrias cancellatus MCCULLOCH 1916 – 15 ×

844a

844c

844b

845

846a

846b

847

322

Schwarzhans: Pleuronectiformes

Typhlachirus HARDENBERG 1931

Type-species: Synaptura lipophthalma JANOS 1881

syn. Cryptops HARDENBERG 1931 (type-species:

C. caeca; syn. T. lipophthalma)

Remarks: Otoliths of Typhlachirus have not been

available for investigation. A specimen in the

BMNH collection was found to have its otoliths

dissolved by formalin.

Typhlachirus is thought to be related to Brachi-

rus and/or Zebrias (CHABANAUD, 1948).

Species and distribution: Typhlachirus is known

from two species – T. lipophthalmus from Borneo

and T. sorsogonensis from the Philippines – both

of which have been collected very rarely.

Pardachirinae

7.8.7 Pardachirus Group

Genera: The Pardachirus Group contains three

recent genera – Aseraggodes, Pardachirus (with Lia-

chirus as a junior synonym) and Parachirus – and

two newly erected fossil otolith based genera from

the European Eocene – Praearchirolithus and Pseu-

dopardachirolithus. The two fossil records from

Eocene times prove the ancient origin not only of

the Soleidae but also of the subfamily Pardachir-

inae, which in many respects is the most apomor-

phic subfamily of the Soleidae.

Definition and relationship: The otoliths of the

Pardachirus Group like those of the related Hetro-

mycteris Group are characterized by their com-

pressed, high bodied outline, the smooth convex

inner face and the shallow sulcus. In contrast to

the otoliths of the Heteromycteris Group the cir-

cumsulcal depression (well connected around the

cauda) runs relatively close to the rims of the

otoliths and is often very narrow, sometimes re-

duced to a furrow only. Also the cauda is not

enlarged.

The otoliths of the Pardachirinae bear close

resemblance to the Cynoglossidae and it is quite

probable that the Cynoglossidae have derived

from them. Cynoglossid otoliths are character-

ized by the unique widened cauda and the fused

colliculi resulting in a “hammer” shaped sulcus.

This pattern is already foreshadowed in the Hete-

romycteris Group (see respective entries). On the

other hand Cynoglossidae share the narrow cir-

cumsulcal depression which runs close to the

otolith rims with the Pardachirus Group.

†Praearchirolithus n.gen.

Type-species: genus Soleidarum schultzei NOLF &

LAPIERRE 1979

Name: A combination of prae (lat. = early) and

the generic name Achirus; ending -lithus indicates

it being an otolith based fossil genus.

Diagnosis: A fossil otolith based genus of the

family Soleidae, subfamily Pardachirinae,

Pardachirus Group with the following characters.

The otoliths are small, not exceeding 1.5 mm,

compact, moderately thickset and with an almost

circular outline. Ventral rim deeply and regularly

curving, dorsal rim flat, with pre- and postdorsal

angles. They represent the only genus in the group

with an index l:h of more than 1.0. The sulcus is

narrow, slightly deepened, particularly so the

848a

848c

848b

849

850

Fig. 848: Zebrias zebra (BLOCH 1785) – 15 ×

Figs. 849-850: Zebrias quagga (ALCOCK 1890) – 15 ×

323

Piscium Catalogus, Part Otolithi piscium, Vol. 2

small cauda. Inner face otherwise rather smooth

and moderately convex. Circumsulcal depression

narrow, running close to the rims of the otolith.

Rims rather thickset. Outer face smooth, slightly

convex.

Measurements:

l:h h:t ol:cl oh:ch con.i

†schultzei 1.05-1.10 2.6-2.8 1.7-2.1 1.0-1.25 2.4-2.5

Side dimorphism: Not apparent.

Variability: Very limited to details of the outline,

especially the expression of the dorsal rim, and

minor modifications of the sulcus proportions.

Discussion: Praearchirolithus no doubt represents

the most “primitive” genus in the Pardachirus

Group evidenced by the high index l:h and the

simple character status of sulcus and otolith out-

line.

Species and distribution: Praearchirolithus is a

monospecific genus with P. schultzei from the

Upper Eocene of France, Paris Basin.

Praearchirolithus schultzei

(NOLF & LAPIERRE 1979)

Figs. 851-853

syn. genus Soleidarum schultzei NOLF & LAPI-

ERRE 1979 – NOLF & LAPIERRE 1979: pl. 6,

figs. 21-23 (

non figs. 24-25)

Investigated otoliths: 13 otoliths (paratypes)

from the Upper Eocene, Auversian of Ronquer-

olles, France, coll. IRSNB.

Distribution: Upper Eocene of France (Paris

Basin)

Aseraggodes KAUP 1858

Type-species: Aseraggodes guttulatus KAUP 1858

syn. Coryphillus CHABANAUD 1931 (type-spe-

cies: Aseraggodes filiger), possible subgenus

syn. Beaufortella CHABANAUD 1943 (type-spe-

cies: Aseraggodes abnormis)

syn. Synclidopus CHABANAUD 1943 (type-spe-

cies: Solea macleayana), possible subgenus

Diagnosis: Thin to moderately thickset com-

pressed otoliths; ventral rim deeply and mostly

regularly curving, dorsal rim more shallow, often

irregularly curving, with massive, variable pre-

dorsal and less pronounced postdorsal angles,

anterior rim blunt, posterior rim blunt, nearly

vertically cut or broadly rounded, rarely concave.

Index l:h less than 1.00. Otolith size up to 2.5 mm,

diagnostic maturity probably reached at about

1.2 to 1.5 mm.

Sulcus variable in width, moderately shallow,

but sometimes deepened, position slightly supra-

median, anteriorly reaching close to the anterior

rim of the otolith. Ostium usually wider than

cauda and usually not much longer. Dorsal and

ventral depressions moderately wide, somewhat

deepened and well connected around the cauda

to form a circumsulcal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims more or less thick-

set.

Figs. 851-853: Praearchirolithus schultzei (NOLF & LAPIERRE 1979) – 25 ×

853a

851c

851b

851a

853b

852

324

Schwarzhans: Pleuronectiformes

Measurements:

l:h h:t ol:cl oh:ch con.i

kobensis 0.95-1.00 2.9-3.3 1.2-1.4 1.0-1.35 2.5-3.8

cyaneus 0.85-0.95 3.7 0.9-1.0 1.0-1.15 4.0

klunzingeri 1.05 3.8 0.9-1.05 0.95 3.2

macleayanus 1.05 2.4 2.2 1.35 2.2

filiger 0.95 3.3 1.0 0.95 2.6

Side dimorphism: Not apparent.

Variability: Details of the outline and propor-

tions of otolith and sulcus are all apt to some,

usually minor, modifications.

Discussion: Except for A. macleayanus otoliths of

the genus Aseraggodes are characterized by the

rather low index ol:cl and the relatively flat inner

face with the rather wide circumsulcal depres-

sion. In A. filiger the anterior sulcal opening is

reduced. The two somewhat aberrant species

mentioned may be regarded as representatives

of distinct subgenera or genera (Synclidopus and

Coryphillus respectively). However, the genus

Aseraggodes is very specious and otoliths so far

are only known from relatively few species. More

material of this interesting genus has to be inves-

tigated before any further conclusions can be

drawn based on otoliths.

Aseraggodes represents a somewhat separate

lineage within the Pardachirus Group.

Species and distribution: Aseraggodes is a spe-

cious genus widely distributed throughout the

Indo-West Pacific. The following list of 22 species

may not be complete: A. abnormis, A. bahamondi,

A. beauforti, A. cyaneus, A. dubius, A. filiger, A. gut-

tulatus, A. haackeanus, A. herrei, A. kaianus, A. klun-

zingeri, A. kobensis, A. macleayanus, A. melanostic-

tus, A. microlepidotus, A. normani, A. ocellatus,

A. persimilis, A. sinusarabici, A. smithi, A. texturatus,

A. whittakeri. Of these species A. herrei from the

Galapagos Islands is the only species outside the

Indo-West Pacific.

Aseraggodes kobensis

(STEINDACHNER 1896)

Figs. 854-858

Investigated otoliths: 6 otoliths (3 left and 3 right

side) from off Kochi, Japan, ZMH Ot.11.6.1995.1-

6 (leg. Sasaki).

Figs. 854-858: Aseraggodes kobensis (STEINDACHNER 1896) – 15 ×

855a

854c

854b

854a

855b

856

858

857

325

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: A rather flat and roundish otolith

with irregularly curving dorsal and posterior

rims.

Distribution: Coasts of Japan.

Aseraggodes cyaneus (ALCOCK 1890)

Figs. 859-861

syn. Solea umbratilis ALCOCK 1894

Investigated otoliths: 3 otoliths (1 left and 2 right

side) from the Bay of Bengal, ZMH Ot. 11.6.1995.7-

8 (leg. BMNH 1928.3.20.49-51) and BMNH

1928.3.20.49-51.

Discussion: Very similar to A. kobensis, but some-

what more compressed and thin.

Distribution: Persian Gulf to the Bay of Bengal.

Aseraggodes klunzingeri (WEBER 1908)

Figs. 863-864

Investigated otoliths: 2 otoliths (left and right

side) from New Guinea, ZMH Ot.11.6.1995.9 (leg.

BMNH 1938.2.24.1-3) and BMNH 1938.2.24.1-3.

Discussion: Similar to A. kobensis and A. cyaneus

but less compressed and with a more regular

outline.

Distribution: Southern New Guinea ascending

into the Lorentz and Meraukee rivers, northern

Australia in Drysdale and Ord rivers.

Aseraggodes macleayanus (RAMSAY 1881)

Fig. 862

Investigated otoliths: 1 otolith (left side) from

Queensland, Australia, ZMH Ot.11.6.1995.10 (leg.

ZMH 20110).

Discussion: Otoliths of A. macleayanus are easily

recognized by their outline (backward shift of the

ventral rim and concave posterior rim), the deep-

ened and widened ostium, the high index ol:cl

and the very narrow ventral portion of the cir-

cumsulcal depression. In this respect they show

quite some similarities with otoliths of the genus

Pardachirus. Possibly A. macleayanus represents a

distinct genus or subgenus of Aseraggodes, name-

ly Synclidopus.

Distribution: Australia, coasts of Queensland.

Aseraggodes filiger WEBER 1913

Fig. 865

Investigated otoliths: 1 otolith (left side) from

Singapore, BMNH 1934.9.6.2.

Discussion: This otolith is characterized by its

regular roundish outline and the anteriorly re-

duced sulcus. It may represent a distinct subge-

nus of Aseraggodes, namely Coryphillus.

Distribution: Sea of Java to Malaysia.

Figs. 859-861: Aseraggodes cyaneus (ALCOCK 1890) – 15 ×

859c

859b

859a

861

860

326

Schwarzhans: Pleuronectiformes

†Pseudopardachirolithus n.gen.

Type-species: Pseudopardachirolithus nolfi n.sp.

Name: A combination of pseudo and the genus

name Pardachirus; ending -lithus indicates it be-

ing an otolith based fossil genus.

Diagnosis: A fossil, otolith based genus of the

family Soleidae, subfamily Pardachirinae,

Pardachirus Group with the following characters.

The otoliths are small, up to 2.0 mm, compact

and thickset with an index l:h well below 1.0.

Ventral rim deeply curved, somewhat shifted

backwards, dorsal rim high, somewhat irregular-

ly curved, anterior rim blunt, posterior rim near-

ly vertically cut, slightly concave. Sulcus narrow

to moderately wide, shallow, reaching close to

the anterior rim of the otolith. Cauda much shorter

than ostium. Circumsulcal depression dorsally

widened, ventrally very narrow, resembling a

ventral furrow, running close to the otolith rims.

Inner face strongly convex, smooth; outer face

flat, smooth. Rims rather sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

†nolfi 0.75-0.85 2.7 1.65-2.4 0.95-1.05 1.6

†sulci 0.90-1.00 2.5 1.85-2.0 0.8-0.9 1.6

Side dimorphism: Not apparent.

Variability: Ornamentation of the outline and

proportions of the otolith are apt to some minor

modifications.

Discussion: Otoliths of Pseudopardachirolithus are

quite similar to those of Pardachirus. However,

they are more thickset, with a more convex inner

face and a more “primitive” character status of

the circumsulcal depression and the sulcus. Ap-

parently, both genera are closely related. The fos-

sil Praearchirolithus is more roundish in outline

and with a much less convex inner face, thus

representing a still more primitive character state.

Species and distribution: Two fossil species –

P. nolfi from the Upper Eocene of France and

P. sulci from the Upper Oligocene and Lower Mio-

cene of France.

Fig. 862: Aseraggodes macleayanus (RAMSAY 1881) – 15 ×

Figs. 863-864: Aseraggodes klunzingeri (WEBER 1908) – 15 ×

Fig. 865: Aseraggodes filiger WEBER 1913 – 15 ×

862c

862b

862a

862d

864

865a

863b

863a

865b

865c

327

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Pseudopardachirolithus nolfi n.sp.

Figs. 866-869

syn. genus Soleidarum schultzei – NOLF & LAPI-

ERRE 1979: pl. 6, figs. 24-25 (

non figs. 21-23)

Name: In honor of Dirk Nolf, renown otolith spe-

cialist from Brussels, Belgium.

Holotype: Fig. 866, IRSNB P.

Type locality: Ronquerolles, sheet Creil, x=

590275, y=162300, Paris Basin, France.

Age: Auversian, Upper Eocene.

Paratypes: 6 otoliths (figs. 867-869), topo- and stra-

titypic, IRSNB P (all from the paratype sequence

of genus Soleidarum schultzei).

Diagnosis: Extremely high bodied, compact,

small, thickset otoliths with an index l:h of 0.75 to

0.85. Ventral rim very deeply curving. Inner face

strongly convex, smooth. Sulcus very narrow,

shallow, ostium about two times as long as cauda.

Description: Outline: Otoliths small (less than

1.5 mm), very high and compact. Ventral rim

deeply curving, dorsal rim likewise, but some-

what irregularly, anterior rim blunt or broadly

rounded, posterior rim vertically cut with faint

concavity. Occasionally rims delicately crenulat-

ed. Otoliths very thickset.

Inner face: Strongly convex and smooth. Sul-

cus long, narrow, shallow, with slightly supra-

median position. Ostium about two times as long

as cauda, similar in width. Separation of colliculi

distinct. Circumsulcal depression close to the rims

of the otolith, dorsally widened, ventrally reduced

to a narrow line.

Other views: Rims rather sharp. Outer face

smooth, nearly flat.

Side dimorphism: Not apparent.

Ontogeny and variability: Proportions of the

otolith and details of the outline may vary slightly.

Sometimes the otolith margins are delicately or-

namented. This seems to occur in the smallest

specimens only and could be an ontogenetic effect.

Discussion: Holotype and paratypes of this spe-

cies originally have been described in the type

sequence of genus Soleidarum schultzei (see Prae-

archirolithus schultzei). However, they are easily

distinguished by the characters given in the di-

agnosis. The geologically younger P. sulci from

the Upper Oligocene and Lower Miocene of

France is somewhat less high bodied with the

backward shifted ventral rim and a wider sulcus.

Both species likely represent part of a fossil line-

age.

Distribution: Upper Eocene of France (Paris

Basin).

Pseudopardachirolithus sulci

(STEURBAUT 1984)

Figs. 870-871

syn. genus aff. Paraplagusia sp. – STEURBAUT

1979: pl. 11, fig. 18

syn. Solea sulci STEURBAUT 1984 – STEURBAUT

1984: pl. 35, figs. 24-26

Investigated otoliths: 2 otoliths (left and right

side), paratypes (IRSNB P 4265-4266) from the

Burdigalian, Lower Miocene of Pont-Pourquey,

Aquitaine Basin, France.

Discussion: Similar to P. nolfi (see respective

entry).

Distribution: Upper Oligocene and Lower Mi-

ocene of France (Aquitaine Basin)

Pardachirus GÜNTHER 1862

Type-species: Achirus marmoratus (LACEPEDE

1802)

syn. Liachirus GÜNTHER 1862 (type-species:

L. nitidus, syn. P. melanospilos)

syn. Normanetta WHITLEY 1931 (type-species:

Achirus poropterus)

Diagnosis: Thin to moderately thickset com-

pressed otoliths; ventral rim deeply and regular-

ly curving, somewhat shifted backwards, dorsal

rim more shallow, often irregularly curving, with

massive, variable predorsal and less pronounced

postdorsal angle, anterior rim broadly rounded,

posterior rim blunt to vertically cut, sometimes

with faint concavity. Index l:h 0.90 to 1.05. Oto-

lith size up to 3.0 mm, diagnostic maturity prob-

ably reached at about 1.5 mm.

Sulcus rather narrow, shallow, rarely some-

what deepened, position slightly supramedian,

anteriorly reaching close to the anterior rim of

328

Schwarzhans: Pleuronectiformes

the otolith. Ostium usually narrower than cauda,

much longer. Colliculi nearly fused. Dorsal and

ventral depressions very narrow like a furrow,

well connected around the cauda to form a cir-

cumsulcal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims more or less sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

hedleyi 1.00 3.5 1.75 0.85 2.4

marmoratus 0.95 2.7 1.80 0.70 1.8

pavoninus 0.90 3.4 1.35 0.90 2.5

melanospilos 1.05 3.1 2.40 1.05 2.6

Side dimorphism: Not apparent, according to a

sequence of otoliths of P. pavoninus figured in

CHAINE (1936).

Variability: According to figures by CHAINE

(1936) limited to variations in the proportions of

the otolith and details of the outline.

Discussion: Otoliths of the genus Pardachirus

show a number of similarities with genera of the

Heteromycteris Group (see respective entry) and

also resemble Cynoglossid otoliths, except for that

those show completely fused colliculi and the

peculiar “hammer” shaped sulcus. Pardachirus

and possibly also the related genus Parachirus (of

which otoliths are not known) represent the most

apomorphic genus in the Pardachirus Group.

The monospecific genus Liachirus (L. melano-

spilos) is being placed in synonymy with Pardachi-

rus based on the very close resemblance of its

respective otoliths.

Species and distribution: Pardachirus contains 6

nominal species from the Indo-West Pacific –

P. hedleyi, P. marmoratus, P. melanospilos, P. morrowi,

P. pavoninus and P. poropterus.

Figs. 866-869: Pseudopardachirolithus nolfi n.sp. – 25 ×

Figs. 870-871: Pseudopardachirolithus sulci (STEURBAUT 1984) – 25 ×

866c

870b

866a

869

867

868

866b

870a

871

870c

329

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Pardachirus hedleyi OGILBY 1916

Fig. 872

Investigated otoliths: 1 otolith (left side) from

New South Wales, Australia. BMNH 1925.9.21.4.

Discussion: P. hedleyi is recognized by its some-

what deepened cauda and the still rather wide

circumsulcal depression.

Distribution: Coasts of Queensland and New

South Wales, Australia.

Pardachirus marmoratus (LACEPEDE 1802)

Fig. 873

Investigated otoliths: 1 otolith (left side) from

East Africa, ZMH Ot.11.6.1995.11 (leg. ZMH

20121).

Discussion: Very similar to P. pavoninus but more

rounded in outline, with a more widened cauda

and a more strongly convex inner face.

Distribution: Persian Gulf to Red Sea and East

Africa south to Mozambique and Madagascar.

Pardachirus pavoninus (LACEPEDE 1802)

Fig. 875

syn. Achirus maculatus KUHL & v.HASSELT 1845

Investigated otoliths: 1 otolith (left side) from

Singapore, ZMH Ot.11.6.1995.12 (leg. ZMH

20123).

Discussion: Similar to P. marmoratus but more

high bodied and with conspicuous predorsal

projection; also cauda less widened.

Distribution: Andaman Islands to Japan and

northern Australia.

Pardachirus aff. melanospilos

(BLEEKER 1854)

Fig. 874

syn. Liachirus nitidus GÜNTHER 1862

Investigated otoliths: 1 otolith (left side) from

Daresalam (?), ZMH Ot.11.6.1995.13 (leg. ZMH

20118).

Remarks: The label of the specimen from the

ZMH collection, from which the otolith was ex-

tracted, is either faulty since it indicates as loca-

tion Daresalam in Tanzania or it represents a dif-

ferent species. According to the geographical dis-

tribution pattern, this could then possibly be

P. morrowi.

Discussion: Characterized by a somewhat point-

ed anterior rim and an index l:h of slightly over

1.0.

Distribution: Coasts of India, Indonesia and

China.

Parachirus MATSUBARA & OCHIAI 1963

Type-species: Parachirus xenicus MATSUBARA &

OCHIAI 1963

Remarks: Otoliths of Parachirus have not been

available for investigation. Parachirus is appar-

ently closely related to Pardachirus.

Species and distribution: Parachirus is a mono-

specific genus with P. xenicus known from Japan

through the Indo-West Pacific to South Africa.

7.8.8 Heteromycteris Group

Genera: The Heteromycteris Group (or Hetero-

mycterinae of CHABANAUD, 1939) as under-

stood here contain three genera – Heteromycteris,

Rendahlia and Peltorhamphus. Since NORMAN

(1934) Peltorhamphus has been placed in the Pleu-

ronectidae in the subfamily Rhombosoleinae, al-

though he noted that some genera bear some

superficial resemblance with Soleidae. Accord-

ing to otolith analysis Rhombosoleinae are regard-

ed as a polyphyletic combine (see entries to chap-

ters 5.3.2., the Ammotretis Group, Pleuronectidae

and the Samaris, Pelotretis and Rhombosolea

Groups). However, NORMAN was right in re-

garding similarities of his Rhombosoleinae with

Soleidae as purely superficial, that is except for

Peltorhamphus. Otolith analysis clearly character-

izes Peltorhamphus as a Soleidae, probably close to

Heteromycteris. This conclusion, however, needs to

be verified by other ichthyological investigations.

330

Schwarzhans: Pleuronectiformes

Fishes of the Heteromycteris Group are distrib-

uted from the West African coast through the

Indo-West Pacific. Peltorhamphus is entirely en-

demic to the waters around New Zealand.

Definition and relationship: Otoliths of the He-

tromycteris Group share a number of apomorphic

characters with those of the Pardachirus Group,

such as the shallow sulcus with the short cauda,

the smooth convex inner face, the narrow circum-

sulcal depression and the general outline of the

otolith. Differing from otoliths of the Pardachirus

Group is the position of the circumsulcal depres-

sion at some distance from the rims of the oto-

liths and the tendency to enlarge the cauda.

The latter character, the widened cauda, has

further developed in Cynoglossidae to the char-

acteristic “hammer” shaped sulcus with complete-

ly fused colliculi. In fact the overall pattern of

Cynoglossid otoliths show good resemblance to

those of the Heteromycteris and Pardachirus

Groups. Fishes of the Heteromycteris Group too

resemble cynoglossids in the loss of the pectoral

fins and the incipiently hooked mouth. I there-

fore postulate that the Cynoglossidae have de-

rived from near the Pardachirinae and there pos-

sibly the Heteromycteris Group (see also entry to

Cynoglossidae).

Fig. 872: Pardachirus hedleyi OGILBY 1916 – 15 ×

Fig. 873: Pardachirus marmoratus (LACEPEDE 1802) – 15 ×

Fig. 874: Pardachirus aff. melanospilus (BLEEKER 1854) – 15 ×

Fig. 875: Pardachirus pavoninus (LACEPEDE 1802) – 15 ×

872c

872a

872b

873c

873a

873b

874c

874a

874b

875c

875a

875b

331

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Heteromycteris KAUP 1858

Type-species: Heteromycteris capensis KAUP 1858

syn. Amate JORDAN & STARKS 1906 (type-spe-

cies: Achirus japonicus)

syn. Monodichthys CHABANAUD 1925 (type-

species: M. proboscideus)

Diagnosis: Thin to moderately thickset, rather

elongate otoliths; ventral rim not very deeply and

mostly regularly curving, somewhat shifted back-

wards, dorsal rim more shallow, often irregularly

curving, with massive, variable predorsal and less

pronounced postdorsal angle, anterior rim round-

ed, posterior rim blunt, rounded. Index l:h 1.20 to

1.40. Otolith size up to 3.5 mm, diagnostic matu-

rity probably reached at about 1.2 mm.

Sulcus rather narrow, moderately shallow to

shallow, position median to slightly supramedi-

an, anteriorly reaching close to the anterior rim

of the otolith. Ostium narrower than cauda and

much longer. Dorsal and ventral depressions rath-

er narrow, somewhat deepened, close to the sul-

cus and well connected around the cauda to form

a circumsulcal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims sharp to moder-

ately thickset.

Measurements:

l:h h:t ol:cl oh:ch con.i

japonicus 1.25-1.40 1.9-2.2 2.3-2.8 0.6-0.75 2.2-2.6

oculus 1.35-1.40 2.2 2.0-2.5 0.7-1.0 2.5

capensis 1.20 3.2 2.8 0.7 2.8

Side dimorphism: Not data.

Ontogeny and variability: A rather large otolith

of H. japonicus shows a more gently curving ovale

outline and is also more thickset than smaller ones.

Variability apparently is very limited in this

genus, restricted mainly to details of the dorsal

rim and variations in the index oh:ch.

Discussion: Otoliths of Heteromycteris are very

similar to those of the related genus Rendahlia.

However, the latter are more compressed and the

shape of the sulcus has further advanced to re-

semble Cynoglossidae.

Species and distribution: Heteromycteris contains

6 nominally valid species – H. proboscideus from

West Africa, H. capensis from South Africa, H. ocu-

lus from the Indian subcontinent, H. cheni from

China and H. japonicus and H. matsubarai from

Japan. H. hartzfeldi is being placed in the genus

Rendahlia (see respective entry).

Heteromycteris japonicus

(TEMMINCK & SCHLEGEL 1846)

Figs. 876-877

Investigated otoliths: 2 otoliths (left side) from

the Inland Sea of Japan, ZMH Ot.12.6.1995.1 (leg.

BMNH 1905.6.6.223-7) and BMNH 1905.6.6.223-7.

Discussion: Rather thickset otoliths with a slight-

ly deepened sulcus.

Distribution: Coasts of China and Japan.

Heteromycteris oculus (ALCOCK 1889)

Figs. 878-879

Investigated otoliths: 2 otoliths (left side) from

the Ganjam coast, India, ZMH Ot.12.6.1995.2 (leg.

BMNH 1928.3.20.52-56) and BMNH 1928.3.20.52-

56.

Discussion: Otoliths of H. oculus are character-

ized by their rather massive predorsal projection.

Distribution: Coasts of India.

Heteromycteris capensis KAUP 1858

Fig. 880

Investigated otoliths: 1 otolith (left side) from

False Bay, South Africa, BMNH 1930.5.6.43.

Discussion: Otolith rather thin and more com-

pressed than those of the two other species.

Distribution: Coasts of South Africa.

Rendahlia CHABANAUD 1930

Type-species: Achirus jaubertensis RENDAHL

1923

Diagnosis: Thin, compressed otoliths; ventral

rim deeply and mostly regularly curving, some-

332

Schwarzhans: Pleuronectiformes

what shifted backwards, dorsal rim more shal-

low, often irregularly curving, with weak predor-

sal and pointed postdorsal angle, anterior rim

rounded, sometimes pointed, posterior rim blunt,

incipiently concave. Index l:h 1.05 to 1.15. Otolith

size may be up to 3.0 mm, diagnostic maturity

probably reached at about 1.0 mm.

Sulcus rather narrow, moderately shallow to

shallow, position slightly supramedian, anteriorly

reaching close to the anterior rim of the otolith.

Ostium narrower than cauda and longer. Dorsal

and ventral depressions rather narrow, somewhat

deepened, close to the sulcus and well connected

around the cauda to form a circumsulcal depres-

sion.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

hartzfeldi 1.05 2.9 nm 0.6 2.5

jaubertensis 1.10-1.15 3.1 1.8-2.0 0.6 1.5

Side dimorphism: The single right hand otolith

of R. jaubertensis shows a somewhat smaller,

slightly deepened sulcus.

Discussion: Otoliths of Rendahlia are very simi-

lar to Heteromycteris. They differ in being more

compressed and showing a more widened cauda

(index oh:ch) thus more closely resembling Cyno-

glossid otoliths.

Figs. 876-877: Heteromycteris japonicus (TEMMINCK & SCHLEGEL 1846) – 15 ×

Figs. 878-879: Heteromycteris oculus (ALCOCK 1889) – 15 ×

Fig. 880: Heteromycteris capensis KAUP 1858 – 15 ×

880a

876a

876b

877c

877a

877b

878c

878a

878b

879

880b

333

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Species and distribution: Originally described

as a monospecific genus I have also placed

R. hartzfeldi in this genus, purely based on its

otolith morphology.

Rendahlia hartzfeldi (BLEEKER 1853)

Fig. 881

syn. Heteromycteris normani CHABANAUD 1935

Investigated otoliths: 1 otolith (left side) from

Singapore, BMNH 1934.9.6.4.

Discussion: Otoliths of R. hartzfeldi are readily

recognized by the pointed postdorsal angle and

the completely fused colliculi. In this respect they

almost perfectly resemble Cynoglossid otoliths,

differing mainly in the circumsulcal depression

located close to the sulcus.

Distribution: Gulf of Bengal, Malaysia, Indone-

sia and New Guinea.

Rendahlia jaubertensis (RENDAHL 1923)

Figs. 882-883

Investigated otoliths: 2 otoliths (left and right

side) from Lord Byron Island, Timor Sea off Der-

by, NW-Australia, 16°10’S/123°28’E, ZMH

Ot.12.6.1995.3-4 (leg. WAM P 30319-023).

Discussion: Similar to R. hartzfeldi, but with

pointed anterior tip and separated colliculi.

Distribution: Northwest Australia.

Peltorhamphus GÜNTHER 1862

Type-species: Peltorhamphus novaezeelandiae

GÜNTHER 1862

Diagnosis: Thin to moderately thickset, com-

pressed otoliths; ventral rim deeply and regular-

ly curving, shifted backwards, dorsal rim more

shallow, often irregularly curving, with massive,

variable pre- to middorsal projection and round-

ed postdorsal angle, anterior rim rounded, pos-

terior rim blunt, rounded to vertically cut. Index

l:h 0.75 to 1.10. Otolith size up to 4.5 mm, diag-

nostic maturity probably reached at about 1.5 to

2.0 mm.

Sulcus moderately wide, moderately shallow

to shallow, cauda sometimes deepened, position

median to slightly supramedian, anteriorly reach-

ing close to the anterior rim of the otolith or open-

ing to it (pseudoostial opening). Ostium narrow-

er than cauda and much longer. Separation of

colliculi variable, sometimes quite indistinct.

Dorsal and ventral depressions moderately wide,

slightly deepened, close to the sulcus and well

connected around the cauda to form a circumsul-

cal depression.

Inner face markedly convex, smooth; outer

face almost flat, smooth. Rims sharp.

Measurements:

l:h h:t ol:cl oh:ch con.i

novaezeelandiae 1.00-1.10 4.2 (1.6-2.2) 0.85-0.9 2.1-2.5

†flexodorsalis 1.05-1.10 2.7 2.1-2.4 0.65-0.9 2.3

latus 1.10 3.3 1.8 1.0 2.6

tenuis 0.90-1.00 3.1 2.1-2.7 0.8-1.0 1.8-2.0

†fordycei 0.75-0.80 3.5 1.6-1.9 0.95-1.0 2.2

Side dimorphism: Not apparent. Sometimes it

seems that otoliths of the right side are slightly

more compressed than those of the left side.

Ontogeny and variability: Otoliths of 2 mm of

size and smaller are usually more rounded in

outline than larger ones.

Variability is moderate, restricted to details of

the outline and proportions of otolith and sulcus.

Also the degree of the ostial opening is apt to

some modifications.

Discussion: Peltorhamphus is generally regarded

as a Pleuronectidae, subfamily Rhombosoleinae

(NORMAN, 1934). Otoliths, in my opinion, clearly

demonstrate this genus to represent a Soleidae,

probably close to Heteromycteris. This hypothesis,

however, needs to be verified by other ichthyo-

logical investigations.

Species and distribution: Peltorhamphus is en-

demic to the sea around New Zealand. It con-

tains 3 recent species – P. novaezeelandiae, P. latus

and P. tenuis – plus 2 fossil species – P. fordycei

from the Miocene and P. flexodorsalis from the

Pliocene. Also P. tenuis is known as fossil from

the Pliocene of New Zealand.

334

Schwarzhans: Pleuronectiformes

Peltorhamphus novaezeelandiae

GÜNTHER 1862

Figs. 884-886

Investigated otoliths: 5 otoliths, 4 (left and right

side, figs. 884-886), AIM 2760 (coll. Grenfell) and

1 (right side) from off Wellington, New Zealand,

BMNH 73.12.13.14-15.

Discussion: Otoliths of P. novaezeelandiae are rath-

er compressed with a massive middorsal projec-

tion. The differ from the related fossil P. flexo-

dorsalis in the almost completely fused colliculi.

Also in P. flexodorsalis the middorsal projection is

still more massively developed.

Distribution: New Zealand.

Peltorhamphus flexodorsalis n.sp.

Figs. 888-894

Name: flexus (lat.) = bent and dorsalis, referring

to the very strongly developed middorsal projec-

tion.

Holotype: Fig. 888, BSP 1984 X 117.

Type locality: Martinborough, New Zealand

northern Island.

Age: Wanganuian, Pliocene.

Paratypes: 6 otoliths (figs. 889-894), topo- and

stratitypic, BSP 1984 X 118-123.

Diagnosis: Compressed, massive otoliths with

an extremely strongly developed middorsal pro-

jection. Postdorsal portion often concave. Ostium

and cauda clearly separated, cauda somewhat

deepened, ostium anteriorly open (pseudoostial

opening).

Description: Outline: Otoliths compressed with

a moderately deeply curving ventral rim, shifted

far backwards. Dorsal rim with extremely strongly

developed middorsal projection, often concave

behind. Anterior rim rounded, sometimes with

pseudo-excisura, posterior rim blunt, nearly ver-

tically cut. Otolith compact, moderately thickset.

Inner face: Convex and rather smooth. Sul-

cus long, moderately wide, with median position

and slightly deepened, especially the cauda. Os-

tium at least two times as long as cauda, slightly

narrower, anteriorly open (pseudoostial opening).

Colliculi well separated. Circumsulcal depression

moderately wide, rather shallow, close to the

sulcus, well connected around the caudal tip of

the sulcus.

Other views: Outer face nearly flat, rather

smooth. Rims mostly sharp.

Side dimorphism: Otoliths of the right side seem

to be slightly more compressed than those of the

left side.

Ontogeny and variability: Otoliths of 2 mm of

size and smaller are usually more rounded in

outline than larger ones.

Variability is moderate, restricted to details of

the outline and proportions of otolith and sulcus.

Also the degree of the ostial opening is apt to

some modifications.

Discussion: P. flexodorsalis is very close to the

recent P. novaezeelandiae and may very well rep-

resent the direct ancestor. It differs in the more

strongly developed middorsal projection and the

clear separation of the colliculi.

Fig. 881: Rendahlia hartzfeldi (BLEEKER 1853) – 15 ×

Figs. 882-883: Rendahlia jaubertensis (RENDAHL 1923) – 25 ×

881c

881a

881b

883

882a

882b

335

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Peltorhamphus latus JAMES 1972

Fig. 887

Investigated otoliths: 1 otolith (left side) (para-

type) from the Tasman Bay, New Zealand, 41°0’S/

173°7’E, BMNH 1970.12.15.3-5.

Discussion: Similar to P. novaezeelandiae but with

very shallow middorsal portion and with clearly

separated colliculi. Also the sulcus is rather wide.

Distribution: New Zealand.

Peltorhamphus tenuis JAMES 1972

Figs. 895-899

Investigated otoliths: 1 otolith (left side, fig. 895)

(paratype) from Pegasus Bay, New Zealand,

43°27’S/172°7’E, BMNH 1970.12.15.10-11 and 5

fossil specimens (figs. 896-899) from the Pliocene,

Wanganuian of Martinborough, New Zealand

north island.

Figs. 884-886: Peltorhamphus novaezeelandiae GÜNTHER 1862 – 15 ×

Fig. 887: Peltorhamphus latus JAMES 1972 – 15 ×

884c

884a

884b

886

885a

885b

887c

887a

887b

336

Schwarzhans: Pleuronectiformes

Discussion: Otoliths of P. tenuis are more com-

pressed than those of the other two recent spe-

cies and show a rather gently curving dorsal rim.

Distribution: New Zealand, also known as fos-

sil from the Pliocene of the same area.

Peltorhamphus fordycei

(SCHWARZHANS 1980)

Figs. 900-902

syn. Achirus fordycei SCHWARZHANS 1980 –

SCHWARZHANS 1980: figs. 585-588

Investigated otoliths: 5 otoliths, including holo-

type (fig. 900) and paratypes (figs. 901-902) from

the Double Corner Shellbed Formation, Lillbur-

nian/Waiauan, Middle Miocene of the Waipara

river, sheet S68-137/074, Canterbury, New Zea-

land south island, NZGS.

Discussion: Otoliths of P. fordycei are readily rec-

ognized by their extremely low index l:h.

Distribution: Middle Miocene of New Zealand.

Figs. 888-894: Peltorhamphus flexodorsalis n.sp. – 15 ×

888c

888a

888b

890

892

889

893

891

894

337

Piscium Catalogus, Part Otolithi piscium, Vol. 2

7.9 Cynoglossidae

Genera: The family Cynoglossidae contains 2

large genera – Cynoglossus and Symphurus. Each

of the two genera contains more than 50 species

making them the most speciouss genera of the

Pleuronectiformes. A third genus usually recog-

nized in ichthyological literature – Paraplagusia

(with only few species) – is here regarded as a

subgenus of Cynoglossus (for reasoning see below

and introduction to Cynoglossus). The otoliths of

the various species of both genera show a dis-

tinct clustering. These clusters are presented here

in subgeneric ranking using generic names from

the synonymy lists of the respective genera (see

respective entries). It is envisaged that these clus-

ters could be given generic ranking if supported

by other ichthyological analyses.

Definition and relationship: The Cynoglossidae

are the amalgamation of all left eyed Soleoidei

(and the Soleidae of the right eyed Soleoidei). In

some literature they are subdivided into two sub-

families – the Cynoglossinae and the Symphuri-

nae.

Figs. 895-899: Peltorhamphus tenuis JAMES 1972 – 15 ×

Figs. 900-902: Peltorhamphus fordycei (SCHWARZHANS 1980) – 15 ×

895c

895a

895b

900b

896a

896b

897

900a

900c

901

899

898

902

338

Schwarzhans: Pleuronectiformes

Apparently, Cynoglossidae form a morpho-

logically well defined and dense cluster. Their

otoliths are immediately recognized by the “ham-

mer” shaped sulcus. The sulcus is shallow, not or

not distinctly opening anteriorly and filled with

a uniform colliculum. Anteriorly (representing the

ostium) it is narrow, posteriorly (representing the

cauda) it is extremely widened dorsally and ven-

trally with a nearly vertically cut termination

resulting in the typical “hammer” shaped out-

line. Else, the inner face typically is convex and

smooth, with a narrow furrow-like circumsulcal

depression close to the rims of the otolith. In

outline, the otoliths are often very high bodied,

commonly with a massive predorsal projection

and a far backwardly shifted postventral corner.

The otolith pattern of the Cynoglossidae re-

sembles that of certain genera of the Pardachiri-

nae (Soleidae) even to the point that the “ham-

mer” shaped sulcus is foreshadowed in those

genera. Such initial feature is found in the genera

of the Heteromycteris Group of the Pardachirinae

like in the genus Rendahlia (see respective entries).

The fishes of the Heteromycteris Group too resem-

ble cynoglossids in the loss of the pectoral fins

and the incipiently hooked mouth. From these

observations it may be concluded that the Cy-

noglossidae have derived from near the

Pardachirinae and thus represent a paraphyletic

unit.

The members of the Cynoglossidae have re-

cently been subject to a phylogenetical study by

CHAPLEAU (1987). He regarded the genus Sym-

phurus as the most plesiomorphic in the family

forming the sister group to Cynoglossus and Para-

plagusia, the latter representing the most apomor-

phic one. Similar views were expressed in ME-

NON’s review of the genus Cynoglossus in 1977.

Otoliths, however, point to a completely differ-

ent phylogenetic alignment. Those of the genus

Symphurus exhibit a number of additional and

highly specialized characters (for details see en-

try to genus) which can not possibly be interpret-

ed as plesiomorphic in comparison with the ge-

nus Cynoglossus. Therefore, it may be questioned

whether the seemingly primitive characters ob-

served in fishes of the genus Symphurus may not

possible represent a reduction rather than a ple-

siomorphic character state.

In the fossil record, cynoglossid otoliths are

rare, but both genera are known since Lower

Miocene times (not identifiable to the species in

the case of Symphurus). Typical representatives of

the genus Cynoglossus from the Miocene, howev-

er, document that the genus is probably older

than assumed by MENON (1977). Also its occur-

rence in European sediments contradicts his hy-

pothesis that the genus Cynoglossus had devel-

oped in the Indian Ocean and as lately as Pliocene,

after the Tethyan waterways had been destruct-

ed. The wider present day geographical distribu-

tion of the genus Symphurus is irrelevant in this

respect since it is a genus mostly adapted to deep-

er water. Plate tectonic developments and paleo-

geographic situations should be used much more

carefully to explain recent biogeographic distri-

bution patterns or phylogenetic assumptions,

especially in the (seeming) absence of fossil data.

Distribution: Cynoglossidae are widely distrib-

uted throughout the tropical and subtropical seas.

The genus Cynoglossus chiefly occurs in the shal-

low water of the Indo-West Pacific and with few

species in the East Atlantic. Fishes of the genus

Symphurus are mostly adapted to deeper water

on the continental shelfs and slopes in all tropical

and subtropical oceans.

7.9.1 Cynoglossus Group

Genera: One genus – Cynoglossus. Paraplagusia

is regarded as a subgenus of Cynoglossus (see entry

to genus).

Definition and relationship: Otoliths of the ge-

nus Cynoglossus show the typically shallow “ham-

mer” shaped sulcus with fused colliculi and the

high bodied outline often with a massive predor-

sal projection and a backwardly shifted postven-

tral corner. Typically, the inner face is convex and

smooth, with a narrow circumsulcal depression

running close to the otolith rims.

A similar pattern is foreshadowed in the

Pardachirinae (Heteromycteris Group) from near

which Cynoglossidae are supposed to have de-

rived. Otoliths of the second cynoglossid group,

the Symphurus Group, show further specializa-

tions such as the anteriorly reduced sulcus, a very

special development of the postdorsal and the

postventral portions of the circumsulcal depres-

sion (bilobate) and the backwardly shifted dorsal

rim. It is therefore assumed that Symphurus orig-

inated from near certain species groups within

the genus Cynoglossus, where similar trends can

be observed.

339

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Cynoglossus HAMILTON-BUCHANAN 1822

Type-species: Cynoglossus lingua HAMILTON-

BUCHANAN 1822

syn. Cantoria KAUP 1858 (type-species: Plagusia

potous, syn. C. arel)

syn. Arelia KAUP 1858 (type-species: C. arel)

syn. Icania KAUP 1858 (type-species: C. cynoglos-

sus) – subgenus

syn. Trulla KAUP 1858 (type-species: Trulla can-

tori, syn. C. borneensis) – subgenus

syn. Paraplagusia BLEEKER 1865 (type-species:

Pleuronectes bilineatus) – subgenus

syn. Rhinoplagusia BLEEKER 1875 (type-species:

Plagusia japonica)

syn. Usinostia JORDAN & SNYDER 1900 (type-

species: Plagusia japonica)

syn. Areliscus JORDAN & SNYDER 1900 (type-

species: C. joyneri)

syn. Cynoglossoides VON BONDE 1922 (type-spe-

cies: C. attenuatus)

syn. Dollfusichthys CHABANAUD 1931 (type-

species: D. sinusarabici)

syn. Dexiourius CHABANAUD 1947 (type-spe-

cies: C. semilaevis) – subgenus

syn. Cynoglossoides [not VON BONDE 1922]

SMITH 1949 (type-species: C. ecaudatus)

Diagnosis: Thin to moderately thickset, ovale to

high bodied otoliths; ventral rim deeply curving,

anteriorly inclined, posteriorly with massive cor-

ner towards the posterior rim, dorsal rim more

shallow with postdorsal angle and usually mas-

sive predorsal projection, anterior rim broadly

rounded, posterior rim high, oblique or vertical-

ly cut, with or without concavity, or broadly

rounded. Maximal otolith size variable, up to and

more than 5 mm in large species and 1.5 to 2 mm

in dwarfed species.

Sulcus usually shallow, occasionally some-

what deepened, with fused colliculi, typical “ham-

mer” shaped outline, not or indistinctly opening

anteriorly. Circumsulcal depression well devel-

oped but very narrow, often furrow like, some-

times postdorsally somewhat widened, running

close to the otolith rims.

Inner face markedly to strongly convex, usu-

ally rather smooth; outer face flat to markedly

concave, rarely convex, usually smooth. Rims

usually sharp, occasionally more thickset, not or

only faintly ornamented.

Subgeneric definitions: The various species of

the genus Cynoglossus can be subdivided in spe-

cies clusters by means of otolith analysis to which

subgeneric ranking and naming from the synon-

ymy list can provisionally be applied (see discus-

sion lateron for more details).

Otoliths of the subgenus Trulla show a very

convex and rather smooth inner face. The pre-

dorsal projection is strongly developed.

Otoliths of the subgenus Dexiourius are sim-

ilar to Trulla, but usually with a less pronounced

predorsal projection and a not so much widened

cauda, often with a rounded termination. – Both

subgenera are supposed to represent rather ple-

siomorphic otolith patterns.

Otoliths of the subgenus Paraplagusia again

have a very convex and very smooth inner face.

The sulcus is completely flat and a predorsal

projection is completely missing.

The subgenus Cynoglossus contains a number

of dwarfed species. Otoliths have a rather flat

inner face and the ostium is anteriorly narrowed,

often pointed. A predorsal projection is devel-

oped. The circumsulcal depression has developed

some kind of secondary funnel-shaped connec-

tion towards the extended dorsal and ventral tips

of the cauda. This character is similarly devel-

oped as in the genus Symphurus.

The subgenus Icania again contains numer-

ous dwarfed species. Otoliths resemble those of

the subgenus Cynoglossus in the rather flat inner

face and the moderate predorsal projection but

lack the anterior narrowing of the ostium and the

peculiar development of the circumsulcal depres-

sion. Instead a tendency is observed to smoothen

the outline of the sulcus. This has developed fur-

thest in C. carpentari where the sulcus secondar-

ily has become ovale again and is also consider-

ably deepened.

Measurements:

l:h h:t l:ol ch:oh con.i

subgenus Trulla

canariensis 0.95-1.00 3.3 1.5-1.6 1.9 3.0

†obliqueventralis 0.80-0.85 4.3 1.7 2.4-2.6 2.6

dubius 1.20-1.30 4.9 1.7-1.8 1.7-1.9 3.7

borneensis 1.05-1.15 4.0 1.6-1.8 1.9-2.1 3.0

senegalensis 1.10 3.3 1.7 2.0 2.9

quadrilineatus 1.10-1.20 2.6-3.0 1.5 1.5-1.6 2.6

lida 1.25 3.0 1.5 2.0 2.6

subgenus Dexiourius

kapuasensis 1.05 2.8 1.6 2.6 2.1

heterolepis 1.30 2.4 2.0 1.7 2.8

feldmanni 0.95 3.4 1.5 2.1 2.5

semilaevis 1.10 3.8 1.9 2.0 2.6

340

Schwarzhans: Pleuronectiformes

gracilis 1.00 4.2 1.8 2.3 3.2

abbreviatus 1.00 5.0 1.7-1.9 2.0 2.3

trigrammus 1.05 3.3 1.7 2.1 3.4

subgenus Paraplagusia

dispar 1.05 4.4 1.5-1.6 1.8-1.9 2.5

japonicus 1.05-1.10 3.4 1.6-1.71.5-1.8 1.7-1.9

bilineatus 1.15 3.7 1.6 2.2 1.9

blochi 1.40 3.5 1.8 1.7 2.3

unicolor 1.15 3.2 1.8 1.8 1.9

subgenus Cynoglossus

arel 1.05-1.10 3.7 1.6-1.8 3.5-4.1 6.0

robustus 1.10-1.15 4.1 1.7-1.9 3.3-3.6 4.5

lingua 1.20-1.30 3.0 1.6-1.7 3.1-4.4 5.5

joyneri 1.25-1.35 2.8-3.0 1.6-1.8 1.7-2.2 4.5

itinus 0.85-0.90 3.3 1.5-1.7 2.6-3.4 1.9

kopsi 1.00-1.05 3.8 1.8-1.9 6.5-7.0 2.3

interruptus 0.95 nm 2.2 3.5 nm

sealarki 1.00 3.6 1.9-2.1 3.6-3.9 2.6

zanzibarensis 1.15 3.1 1.9 3.0-4.5 3.7

subgenus Icania

broadhursti 0.90 3.5 1.4-1.6 2.4-2.9 3.4

maculipinnis 0.90 3.2 1.6-1.7 2.7-3.0 2.6

gilchristi 0.90 3.4 1.8 2.4 2.0

puncticeps 0.85-0.90 4.1 1.8-1.9 2.2-2.4 1.9

†leuchsi 0.85-0.95 4.0 1.6-1.8 2.3-2.6 nm

cynoglossus 1.15 3.0 1.8 1.7 3.7

semifasciatus 1.10 2.8 1.9 2.4 3.0

monopus 1.20 3.2 2.1 1.3 3.0

carpentari A 1.30-1.50 2.4-2.6 1.8-2.4 nm about 7

carpentari B 1.20 3.2 1.9-2.3 nm about 10

Side dimorphism: Usually not apparent. Some-

times a very faint degree of side dimorphism is

seen in details of the outline.

Ontogeny and variability: Smaller otoliths are

usually more gently rounded and thus less charac-

teristic than larger ones. All in all the degree of

ontogenetical changes is rather small and in most

instances juvenile otoliths can be attributed with-

out much difficulties. However, in the presence

of dwarfed species in the same area differentiation

of otoliths from adult dwarfed species from small

otoliths of large species could become difficult.

Variability in most species is at low or mod-

erate level mainly concerning details of the out-

line and minor variations in sulcus proportions.

Discussion: The various species of the genus Cy-

noglossus have been comprehensively revised by

MENON (1977). He defined six major species

groups, some of them including subgroups (or

complexes, as he termed them). He did not offi-

cially name them as subgenera, because he felt

Cynoglossus to represent a very dense cluster in

itself with a mosaic morphology distribution. Like

in most ichthyological literature Paraplagusia was

then excluded as a separate genus, which ME-

NON reviewed in 1979.

MENON (1977, 1979) stated that “Paraplagu-

sia can be distinguished from Cynoglossus mainly

by its possession of a series of fringes an the lips

on the ocular side. In all other features, including

the osteology, Paraplagusia is very similar to Cy-

noglossus”. Otoliths support this close relation-

ship. In fact, otolith morphology in the genus

Cynoglossus is more diverse than differences of

some of its species to the four species usually

placed in Paraplagusia. It seems that separation of

Paraplagusia from Cynoglossus is mainly based on

a single highly obvious and autapomorphic char-

acter. In my opinion this is a typical case of par-

aphyly. Either the various species groups ob-

served in Cynoglossus have to be raised to genus

level or else Paraplagusia must be regarded as a

subgenus of Cynoglossus in order to arrive at a

sound phylogenetic classification. I have here

chosen the second solution and have included

Paraplagusia in Cynoglossus.

MENON’s groups and complexes have been

divided based on a number of meristic characters

such as presence or absence of lateral lines on the

blind side, number of rays in the caudal fin, size

of eyes, width of interorbital space, shape of snout

and others (f.i. dwarfing of species). I have in-

vestigated otoliths of 35 species of the 54 includ-

ed in this genus (including 4 species traditionally

being placed in Paraplagusia). This covers all of

MENON’s species groups and complexes except

for the monospecific C. macrophthalmus complex

and the C. ecaudatus complex. (An otolith extract-

ed from C. ecaudatus was so brittle due to the

effects of formalin that it fell apart when touched

by the tweezers. However, it seemed to be a com-

pact, thick otolith probably not unlike the one

from C. sealarki). His grouping in most instances

compares very well with the grouping according

to otolith patterns.

The species placed here in the subgenus Trul-

la quite well corresponds to MENON’s canarien-

sis group. I have, however, excluded C. dispar and

placed it in the subgenus Paraplagusia chiefly

because of its otolith morphology, although the

presence of a lateral line on the blind side was

used as a prime character by MENON to define

this group. On the other hand C. lida was tenta-

tively included from MENON’s cynoglossus

group. Otoliths of C. attennatus recently figured

by SMALE et al. (1995) suggest that this species

may also belong to the subgenus Trulla. – ME-

NON regarded this group as the most primitive

in the genus because of the presence of lateral

341

Piscium Catalogus, Part Otolithi piscium, Vol. 2

lines on the blind side. Otoliths suggest this too

since the cauda is not as much widened as com-

pared to the ostium and compared to the situa-

tion in most other groups (index ch:oh mostly

below 2).

The species placed in the subgenus Dexiouri-

us represent MENON’s heterolepis group. How-

ever, unlike MENON I do not regard it as closely

related to the carpentari group (subgenus Icania),

but instead as a still rather primitive group close

to Trulla. In particular the posteriorly rounded

cauda is an indication of the primitive status of

this subgenus.

The subgenus Paraplagusia corresponds to the

genus Paraplagusia of MENON (1977, 1979), only

that C. dispar has tentatively been included as well

(see above). Despite the obvious specialization of

the lips (see above) characterizing the fishes of

this subgenus, otoliths seem to indicate that this

too is still a rather plesiomorphic subgenus (low

index ch:oh). However, the very strongly convex

inner face found in the otoliths of this subgenus

and the shallow predorsal rim must be regarded

as apomorphic developments.

The species placed in the subgenus Cynoglos-

sus comprises the kopsi (to the largest part) and

arel groups of MENON. Species of the kopsi group

are all dwarfed whereas those of the arel group

are large. Still their otoliths depict a number of

specialized features (see earlier) which they share

with each other and they are therefore placed

together in one group. In some of the specialized

features otoliths of this group resemble those of

the genus Symphurus. MENON’s ogilbyi complex

of the kopsi group exhibits quite a different oto-

lith pattern and is placed in the subgenus Icania.

The last subgenus is Icania, comprising ME-

NON’s cynoglossus and carpentari groups and his

ogilbyi complex from the kopsi group. Again spe-

cies of the cynoglossus group are dwarfed, those

of the carpentari group are not. By means of oto-

liths this is probably the most diverse, least well

defined subgenus and some of its members show

the most specialized otolith morphology in this

genus. Also it seems to me that this group could

reasonably be split up into two or even three

separate groups (or subgenera). C. lida of ME-

NON’s cynoglossus group is already removed and

placed in the subgenus Trulla. The roughly trian-

gular shaped otoliths of the dwarfed ogilbyi com-

plex and the puncticeps complex of MENON look

just like small specimens of members of the sub-

genus Trulla, where they could be placed alterna-

tively. MENON’s cynoglossus

and monopus com-

plexes show some special features such as the

nearly flat inner face and the tendency to

smoothen the outline of the sulcus. This charac-

ter is further developed in MENON’s carpentari

group to an ovally shaped sulcus outline (sulcus

is also deepened), which is very untypical for a

cynoglossid otolith. Again this is a very special-

ized feature which could be interpreted to sepa-

rate the carpentari group from the subgenus Ica-

nia altogether. Unfortunatelly, otoliths are not

known from the two of the other species in this

group (paratypes of C. acutirostris in the BMNH

collection were found to have otoliths dissolved

by formalin). Recently, otoliths of C. marleyi have

been figured by SMALE et al. (1995) and they

indeed closely resemble those of C. carpentari. On

the other hand, the otolith pattern of C. monopus

could be interpreted as some kind of plesiomor-

phic character state from which the carpentari

group evolved.

Species and distribution: Including Paraplagu-

sia as a subgenus, Cynoglossus contains some 54

valid species. In alphabetic order they are the

following: C. abbreviatus, C. acutirostris, C. arel,

C. attenuatus, C. bilineatus, C. blochi, C. borneensis,

C. broadhursti, C. browni, C. cadenati, C. canariensis,

C. capensis, C. carpentari, C. cynoglossus, C. dispar,

C. dollfusi, C. dubius, C. durbanensis, C. ecaudatus,

C. feldmanni, C. gilchristi, C. gracilis, C. heterolepis,

C. interruptus, C. itinus, C. japonicus, C. joyneri,

C. kapuasensis, C. kopsi, C. lachneri, C. lida, C. lingua,

C. macrophthalmus, C. macrostomus, C. maculipin-

nis, C. marleyi, C. microlepis, C. microphthalmus,

C. monodi, C. monopus, C. ogilbyi, C. puncticeps,

C. quadrilineatus, C. robustus, C. sealarki, C. semifas-

ciatus, C. semilaevis, C. senegalensis, C. sinusarabici,

C. suyeni, C. trigrammus (regarded as synonym of

C. abbreviatus by MENON), C. unicolor (regarded

as synonym of C. bilineatus by MENON), C. wa-

andersi, C. zanzibarensis. In addition there are two

fossil records – C. leuchsi from the Miocene of

Europe and C. obliqueventralis from the Pliocene

of NW-Africa.

The fishes of the genus Cynoglossus are wide-

ly distributed through the Indo-West Pacific and

along the shores of Australia and West Africa.

One species – C. sinusarabici – has immigrated

into the eastern Mediterranean by ‘Lessepsian

migration’ from the Red Sea through the Suez

Canal.

342

Schwarzhans: Pleuronectiformes

Cynoglossus (Trulla) canariensis

STEINDACHNER 1882

Figs. 903-904

syn. Cynoglossus lagoensis REGAN 1915

Investigated otoliths: 2 otoliths (left and right

side) from off Luanda, Angola, ZMH Ot. 27.6.

1995.1-2 (leg. ZMH 20180).

Discussion: A species with a massive, rounded

predorsal projection, a deep postventral corner

and a rather wide ostium.

Distribution: West Africa, Canary Islands, Sen-

egal to Angola.

Cynoglossus (Trulla) obliqueventralis n.sp.

Figs. 905-906

Name: Referring to the steeply inclined anteri-

or-ventral rim.

Holotype: Fig. 905, SMF P 9327.

Type-locality: Right river banks of the Oued Beth,

ca. 1 km south of Dar Bel Hamri, NW-Morocco.

Age: Lumachelle at the base of the Sands of Dar

Bel Hamri, Lower Pliocene.

Figs. 903-904: Cynoglossus (Trulla) canariensis STEINDACHNER 1882 – 10 ×

Figs. 905-906: Cynoglossus (Trulla) obliqueventralis n.sp. – 10 ×

904c

903

904b

905c

905a

905b

906

904a

343

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Paratypes: 1 otolith (fig. 906), topo- and stratit-

ypic, SMF P 9328.

Diagnosis: Large, very high bodied otoliths (in-

dex l:h 0.80-0.85). Predorsal projection broadly

rounded, anterior-ventral rim steeply inclined,

postventral corner very strongly developed.

Description: Outline: Thin, very high otoliths

with a broadly rounded predorsal projection, a

moderate postdorsal angle, a steeply inclined

anterior-ventral rim, a very strong postventral

corner and a vertically cut, straight to slightly

concave posterior rim. All rims smooth.

Inner face: Smooth and considerably convex,

particularly in the vertical direction. Sulcus “ham-

mer” shaped, shallow, with pseudoostial open-

ing, anteriorly moderately wide, posteriorly much

widened. Colliculi completely fused. Circumsul-

cal depression indistinct, rather shallow, postven-

trally and dorsally somewhat widened.

Other views: Rims sharp. Outer face concave,

smooth.

Discussion: This is the most highly bodied oto-

lith of the genus Cynoglossus. Also the outline of

the otolith is highly characteristic as described in

the diagnosis. C. obliqueventralis probably is re-

lated to C. canariensis.

Cynoglossus (Trulla) dubius DAY 1873

Figs. 907-908

Investigated otoliths: 2 otoliths (left and right

side) from Karachee, India, ZMH Ot.27.6.1995.3

(leg. BMNH 1911.12.6.16) and BMNH 1911.12.

6.16.

Discussion: A rather elongate otolith with a char-

acteristically hooked predorsal projection.

Distribution: West coast of India.

Cynoglossus (Trulla) borneensis

(BLEEKER 1858)

Figs. 909-911

?syn. Plagusia trulla CANTOR 1850

syn. Trulla cantori KAUP 1858

syn. Cynoglossus sinicus WU 1932

Investigated otoliths: 3 otoliths (1 left and 2 right

side) from Singapore, ZMH Ot.27.6.1995.4-5 (leg.

BMNH 1933.7.31.28-29) and BMNH 1933.7.31.28-

29).

Discussion: Very similar to C. dubius but more

compressed.

Distribution: Borneo, Malaya, Thailand and

South China Sea.

Cynoglossus (Trulla) senegalensis

(KAUP 1858)

Fig. 912

syn. Cynoglossus goreensis STEINDACHNER 1882

syn. Cynoglossus simulator CHABANAUD 1949

Investigated otoliths: 1 otolith (right side), ZMH

Ot.27.6.1995.6 (leg. ZMH 20180).

Discussion: A moderately compressed otolith

with a rather feeble postventral corner and a

shallow and broad predorsal projection.

Distribution: West Africa, Senegal to Nigeria.

Cynoglossus (Trulla) quadrilineatus

(BLEEKER 1851)

Figs. 913-914

syn. Achirus bilineatus LACEPEDE 1802 (non Pleu-

ronectes bilineatus BLOCH 1787)

syn. Cynoglossus lineolatus STEINDACHNER

1867

syn. Cynoglossus quinquelineatus DAY 1877

syn. Cynoglossus sindensis DAY 1877

syn. Arelia diplasios JORDAN & EVERMANN

1903

Remarks: Following the inclusion of Paraplagu-

sia as a subgenus in Cynoglossus, C. (Trulla) bilin-

eatus (LACEPEDE 1802) becomes preoccupied by

C. (Paraplagusia) bilineatus (BLOCH 1787).

Investigated otoliths: 2 otoliths (left and right

side) from northern Australia, ZMH Ot.27.6. 1995.

7-8 (leg. WAM).

344

Schwarzhans: Pleuronectiformes

Discussion: These otoliths are characterized by

their extremely wide and somewhat deepened

sulcus.

Figs. 907-908: Cynoglossus (Trulla) dubius DAY 1873 – 10 ×

Figs. 909-911: Cynoglossus (Trulla) borneensis (BLEEKER 1858) – 10 ×

Fig. 912: Cynoglossus (Trulla) senegalensis (KAUP 1858) – 10 ×

Distribution: Widely distributed through the

Indo-West Pacific from Pakistan to Japan and

southward to Australia.

908c

907a

908b

910c

908a

910b

912c

909

912b

910a

912a

911

345

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Cynoglossus (Trulla) lida (BLEEKER 1851)

Figs. 915-916

syn. Plagusia polytaenia BLEEKER 1853

syn. Cynoglossus intermedius ALCOCK 1889

syn. Cynoglossus os FOWLER 1904

Investigated otoliths: 2 otoliths (left and right

side), Ganjam coast, India, ZMH Ot.27.6.1995.9

(leg. BMNH 1928.3.20.131) and BMNH 1928.

3.20.131.

Discussion: Similar to C. quadrilineatus, special-

ly as far as the sulcus is concerned, but with a

more gently curving outline and a conspicuous

concavity at the anterior-ventral rim.

Distribution: East coast of Africa and Pakistan

to Philippines.

Cynoglossus (Dexiourius) kapuasensis

FOWLER 1905

Figs. 917-918

Investigated otoliths: 2 otoliths (right side) from

Sarawak, Borneo, ZMH Ot.27.6.1995.10 (leg.

BMNH 1906.10.29.39-40) and BMNH 1906.10.

29.39-40.

Discussion: Characteristic is the sharply deep-

ened postdorsal portion of the circumsulcal de-

pression.

Distribution: Western Borneo, entering the Ka-

puas river.

Cynoglossus (Dexiourius) heterolepis

WEBER 1910

Fig. 919

Investigated otoliths: 1 otolith (right side) from

the Upper Fly river, Papua New Guinea, BMNH

1933.2.17.1.

Figs. 913-914: Cynoglossus (Trulla) quadrilineatus (BLEEKER 1851) – 10 ×

Figs. 915-916: Cynoglossus (Trulla) lida (BLEEKER 1851) – 10 ×

916c

913a

913b

914c

914a

914b

915

916b

916a

346

Schwarzhans: Pleuronectiformes

Discussion: Untypically otolith with a very shal-

low ventral rim and a very smooth and convex

inner face. Also otolith rather thickset.

Distribution: New Guinea and northern Austral-

ia, entering into rivers.

Cynoglossus (Dexiourius) feldmanni

(BLEEKER 1853)

Fig. 920

syn. Cynoglossus hardenbergi NORMAN 1931

syn. Cynoglossus abentoni STAUCH 1966

Investigated otoliths: 1 otolith (right side) from

Thailand, BMNH 1989.11.20.2.

Discussion: Otolith high, with nearly triangular

outline and slightly deepened postdorsal portion

of the circumsulcal depression.

Distribution: Thailand, Cambodia, Borneo and

Sumatra, entering into rivers.

Cynoglossus (Dexiourius) semilaevis

GÜNTHER 1873

Fig. 921

syn. Arelia rhomaleus JORDAN & STARKS 1906

syn. Cynoglossus roulei WU 1932

Investigated otoliths: 1 otolith (right side) from

Chekiang, China, BMNH 1930.7.28.13.

Discussion: Otolith with rounded caudal tip.

Otherwise very similar to C. gracilis but may be

slightly more elongate.

Distribution: China.

Figs. 917-918: Cynoglossus (Dexiourius) kapuasensis FOWLER 1905 – 10 ×

Fig. 919: Cynoglossus (Dexiourius) heterolepis WEBER 1910 – 10 ×

Fig. 920: Cynoglossus (Dexiourius) feldmanni (BLEEKER 1853) – 10 ×

920b

917

918b

919c

918a

918c

919a

919b

920a

920c

347

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Cynoglossus (Dexiourius) gracilis

GÜNTHER 1873

Fig. 922

syn. Cynoglossus microps STEINDACHNER 1898

syn. Areliscus hollandi JORDAN & METZ 1913

syn. Cynoglossus pellegrini WU 1932

Investigated otoliths: 1 otolith (right side) from

Chekiang, China, BMNH 1930.7.28.12.

Discussion: Otolith with rounded caudal tip.

Very similar to C. semilaevis.

Distribution: Korea and China.

Cynoglossus (Dexiourius) abbreviatus

(GRAY 1835)

Figs. 923-924

syn. Areliscus purpureomaculatus REGAN 1905

Investigated otoliths: 2 otoliths (right side) from

Kiautshou, China, ZMH Ot.27.6.1995.11-12 (leg.

ZMH 20158).

Discussion: Otolith with rounded caudal tip.

Typical is the fine marginal crenulation and the

very convex and smooth inner face.

Distribution: Korea, Japan, Taiwan, China.

Cynoglossus (Dexiourius) trigrammus

GÜNTHER 1862

Figs. 925-927

Investigated otoliths: 3 otoliths (1 left and 2 right

side) from the Canton coast, China, ZMH

Ot.27.6.1995.13-14 (leg. BMNH 1930.7.28.10-11)

and BMNH 1930.7.28.10-11.

Discussion: Otolith with rounded caudal tip.

Similar to C. gracilis but with more smooth rims

and less convex inner face. – MENON (1977)

placed C. trigrammus in synonymy with C. abbre-

viatus, but otoliths indicate that it should be kept

as a separate species.

Distribution: China.

Cynoglossus (Paraplagusia) aff. dispar

DAY 1877

Figs. 928-929

Investigated otoliths: 2 otoliths (left and right

side) from the Seychelles, ZMH Ot.27.6.1995.15

(leg. BMNH 1869.3.1.30-31) and BMNH 1869.3.1.

30-31.

Discussion: Inner face convex, smooth, with

sharp and narrow circumsulcal depression.

Posterior rim concave. Predorsal projection re-

duced. – MENON (1977) placed this species in

his canariensis group (here subgenus Trulla) but

otoliths are very alike those found in other spe-

cies of the subgenus Paraplagusia. The presence

of lateral line on the blind side is different and

thus the supposed re-arrangement needs to be

verified by other ichthyological investigations. –

However, it is also possible, that this specimen

not investigated by MENON rather represents

C. bilineatus. It also originates from a different

geographical location than the type specimens.

Distribution: Seychelles (?), Pakistan and India.

Cynoglossus (Paraplagusia) japonicus

(TEMMINCK & SCHLEGEL 1842)

Figs. 930-931

Investigated otoliths: 2 otoliths (left and right

side) from Enchu Nada, Central Japan, coll. Ohe

#78726-35.

Discussion: Similar to C. bilineatus but with a less

reduced predorsal projection.

Distribution: Korea, Japan and South China.

Cynoglossus (Paraplagusia) bilineatus

(BLOCH 1787)

Fig. 932

syn. Plagusia dipterygia RÜPPELL 1828

syn. Paraplagusia macrocephalus BLEEKER 1875

syn. Plagusia acuminata CASTELNAU 1875

?syn. Plagusia guttata MACLEAY 1878

?syn. Plagusia notata DE VIS 1883

?syn. Plagusia brevirostris KENT 1893

348

Schwarzhans: Pleuronectiformes

syn. Plagusia robinsoni REGAN 1919

?syn. Rhinoplagusia australis RENDAHL 1921

syn. Rhinoplagusia formoana OSHIMA 1927

Investigated otoliths: 1 otolith (right side) from off

Kochi, Japan, ZMH Ot.27.6.1995.16 (leg. Sasaki).

Fig. 921: Cynoglossus (Dexiourius) semilaevis GÜNTHER 1873 – 15 ×

Fig. 922: Cynoglossus (Dexiourius) gracilis GÜNTHER 1873 – 15 ×

Figs. 923-924: Cynoglossus (Dexiourius) abbreviatus (GRAY 1853) – 10 ×

Figs. 925-927: Cynoglossus (Dexiourius) trigrammus GÜNTHER 1862 – figs. 925-926 = 10 ×; fig. 927 = 15 ×

923b

922b

921c

922a

922c

921a

921b

923a

923c

925

924a

924b

926

927c

927a

927b

349

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: Very similar to C. dispar and C. ja-

ponicus. Distinguished from the latter by the re-

duced predorsal projection.

Figs. 928-929: Cynoglossus (Paraplagusia) aff. dispar DAY 1877 – 10 ×

Figs. 930-931: Cynoglossus (Paraplagusia) japonicus (TEMMINCK & SCHLEGEL 1842) – 10 ×

Fig. 932: Cynoglossus (Paraplagusia) bilineatus (BLOCH 1787) – 10 ×

Fig. 933: Cynoglossus (Paraplagusia) blochi BLEEKER 1875 – 15 ×

Fig. 934: Cynoglossus (Paraplagusia) unicolor MACLEAY 1882 – 10 ×

930b

931b

928c

931a

930c

928a

928b

930a

933a

933b

929

934c

934a

934b

932b

932c

932a

350

Schwarzhans: Pleuronectiformes

Distribution: Widely distributed throughout the

Indo-West Pacific, from East Africa through the

Indian Ocean to China and Australia(?).

Cynoglossus (Paraplagusia) blochi

BLEEKER 1875

Fig. 933

Investigated otoliths: 1 otolith (right side) from

Calcutta, India, BMNH 1933.1.2.5.

Discussion: Otolith rather elongate.

Distribution: Pakistan to the Malay Archipela-

go and Australia.

Cynoglossus (Paraplagusia) unicolor

MACLEAY 1882

Fig. 934

Investigated otoliths: 1 otolith (right side) from

Western Australia, ZMH Ot.27.6.1995.17 (leg.

WAM).

Discussion: Similar to C. japonicus but may be

more elongate. The presence of the predorsal

angle distinguishes this otolith from C. bilineatus,

which is also the reason why I kept the Austral-

ian specimens separate, contrary to MENON

(1979).

Distribution: Australia.

Cynoglossus (Cynoglossus) arel

(SCHNEIDER 1801)

Figs. 935-940

syn. Cynoglossus melampetalus RICHARDSON

1846

syn. Plagusia grandisquamis CANTOR 1850

syn. Plagusia macrolepidota BLEEKER 1851

syn. Plagusia cantoris BLEEKER 1853

syn. Plagusia oligolepis BLEEKER 1854

syn. Cantoria pinangensis KAUP 1858

syn. Arelia kaupii BLEEKER 1860

syn. Cynoglossus elongatus GÜNTHER 1862

Investigated otoliths: 7 otoliths (3 left and 4 right

side), 4 otoliths identified as C. macrolepidotus (figs.

935-938) from the Persian Gulf, ZMH Ot.27.6.

1995.18-20 (leg. BMNH 1928.3.20.89-90) and

BMNH 1928.3.20.89-90, 2 otoliths identified as

C. melampetalus (figs. 939-940) from Amoy, Chi-

na, ZMH Ot.27.6.1995.21 (leg. BMNH 1924.12.

15.82-86) and BMNH 1924.12.15.82-86), 1 otolith

(not figured) identified as C. arel from Indonesia,

BMNH 1968.9.8.13-14.

Discussion: Otoliths large. Predorsal projection

massive. Sulcus with narrowed, pointed anterior

tip. Similar to C. robustus and C. lingua but more

compressed. Those specimens identified as C. me-

Figs. 935-940: Cynoglossus (Cynoglossus) arel (SCHNEIDER 1801) – 10 ×

938

939b

936c

940

937

936a

936b

939a

935

351

Piscium Catalogus, Part Otolithi piscium, Vol. 2

lampetalus are more regular in outline and with a

less pronounced predorsal projection.

Distribution: Persian Gulf to India and to the

South China Sea, the Philippines and Taiwan.

Cynoglossus (Cynoglossus) robustus

GÜNTHER 1873

Figs. 941-942

syn. Cynoglossus brunneaus REGAN 1905

syn. Cynoglossus inusita JORDAN, TANAKA &

SNYDER 1913

Investigated otoliths: 2 otoliths (left and right

side) from Japan, ZMH Ot.27.6.1995.22 (leg.

BMNH 1960.5.13.1-2) and BMNH 1960.5.13.1-2.

Discussion: Similar to C. arel and C. lingua, with

a very pronounced predorsal projection.

Distribution: Korea, Japan, Taiwan and China.

Cynoglossus (Cynoglossus) lingua

HAMILTON-BUCHANAN 1822

Figs. 943-945

syn. Pleuronectes potous CUVIER 1836

syn. Plagusia macrorhynchos BLEEKER 1851

syn. Cynoglossus acinaceus JENKINS 1910

Figs. 941-942: Cynoglossus (Cynoglossus) robustus GÜNTHER 1873 – 10 ×

Figs. 943-945: Cynoglossus (Cynoglossus) lingua HAMILTON-BUCHANAN 1822 – 10 ×

942b

944

942a

945c

943

941a

941c

945a

941b

945b

352

Schwarzhans: Pleuronectiformes

Investigated otoliths: 3 otoliths (1 left and 2 right

side) from Singapore, ZMH Ot.27.6.1995.23-24

(leg. BMNH 1933.7.31.24-26) and BMNH

1933.7.31.24-26.

Discussion: Very similar to C. arel and C. robus-

tus but somewhat more elongate.

Distribution: Pakistan and India to Thailand and

Vietnam.

Cynoglossus (Cynoglossus) joyneri

GÜNTHER 1878

Figs. 946-949

syn. Cynoglossus lighti NORMAN 1925

syn. Areliscus tenuis OSHIMA 1927

syn. Cynoglossus tshusanensis CHABANAUD

1951

Investigated otoliths: 4 otoliths (2 left and 2 right

side) from Japan, coll. Ohe #76424-26 and #820710-

2A.

Discussion: Small, rather elongate otoliths, with

not much anteriorly narrowed sulcus. Inner face

rather flat. Circumsulcal depression incipiently

bilobate.

Distribution: Korea, Japan, Taiwan and China.

Cynoglossus (Cynoglossus) itinus

(SNYDER 1909)

Figs. 950-953

syn. Cynoglossus punctatus SHEN 1969

Investigated otoliths: 4 otoliths (2 left and 2 right

side) from off Kochi, Japan, ZMH Ot.27.6.1995.25-

28 (leg. Sasaki).

Discussion: Small, compressed otoliths with

nearly triangular outline. Inner face convex. Sul-

cus anteriorly not much narrowed. Circumsulcal

depression bilobate.

Distribution: Japan and Hong Kong.

Cynoglossus (Cynoglossus) kopsi

(BLEEKER 1851)

Figs. 954-958

syn. Cynoglossus brachycephalus BLEEKER 1875

syn. Cynoglossus praecisus ALCOCK 1890

syn. Cynoglossus versicolor ALCOCK 1890

syn. Cynoglossus sibogae WEBER 1913

Investigated otoliths: 5 otoliths (1 left and 4 right

side), 3 otoliths identified as C. kopsi (figs. 954,

955, 958) from the Arafura Sea, ZMH

Ot.27.6.1995.29-30 (leg. BMNH 90.2.26.148) and

BMNH 79.5.4.81, 2 otoliths identified as C. brach-

ycephalus (figs. 956-957) from India, ZMH

Ot.27.6.1995.31-32 (leg. BMNH 1908.3.23.149-52).

Discussion: Similar to C. itinus but with anteri-

orly narrowed and pointed sulcus.

Distribution: Indo-Australian Archipelago and

from Persian Gulf and India to the Philippines

and Taiwan.

Figs. 946-949: Cynoglossus (Cynoglossus) joyneri GÜNTHER 1878 – 10 ×

947a

947b

949a

949b

946

948a

948b

353

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Cynoglossus (Cynoglossus) interruptus

GÜNTHER 1880

Figs. 959-960

syn. Cynoglossus nigropinnatus OCHIAI 1959

Investigated otoliths: 2 otoliths (right side) from

Wakanoura, Japan, ZMH Ot.27.6.1995.33 (leg.

BMNH 1923.2.26.660-7) and BMNH 1923.2.26.660-

7).

Discussion: Very similar to C. kopsi but may be

more compressed.

Distribution: Japan.

Figs. 950-953: Cynoglossus (Cynoglossus) itinus (SNYDER 1909) – 10 ×

Figs. 954-958: Cynoglossus (Cynoglossus) kopsi (BLEEKER 1851) – 10 ×

Figs. 959-960: Cynoglossus (Cynoglossus) interruptus GÜNTHER 1880 – 10 ×

953a

955b

952b

953b

952a

951

950

953c

954

953d

958

957

955d

956

960

955c

955a

959

354

Schwarzhans: Pleuronectiformes

Cynoglossus (Cynoglossus) sealarki

REGAN 1908

Figs. 961-963

Investigated otoliths: 3 otoliths (paratypes, 1 left

and 2 right side) from Saya de Malha Bank, ZMH

Ot.27.6.1995.34-35 (leg. BMNH 1908.3.23.153-6)

and BMNH 1908.3.23.153-6.

Discussion: Moderately large, compressed, rath-

er thickset otoliths with rather gently curving

outline. Sulcus anteriorly narrowed and pointed.

Circumsulcal depression bilobate.

Distribution: Saya de Malha Bank.

Cynoglossus (Cynoglossus) zanzibarensis

NORMAN 1939

Figs. 964-965

Investigated otoliths: 2 otoliths (syntype, left and

right side) from Zanzibar, ZMH Ot.27.6.1995.36

(leg. BMNH 1939.5.24.1812-14) and BMNH 1939.5.

24.1812-14.

Discussion: Very similar to C. sealarki and may

be not distinguishable by means of otoliths.

Distribution: Durban, South Africa, through

Zanzibar to Kenya.

Cynoglossus (Icania) broadhursti WAITE 1905

Figs. 966-967

Investigated otoliths: 2 otoliths (left and right

side) from Western Australia, ZMH Ot.28.6.1995.

1-2 (leg. WAM).

Discussion: Medium sized, high otoliths with

roughly triangular outline. Cauda very wide,

ostium anteriorly not narrowed. Circumsulcal

depression faint, narrow.

Distribution: Western and southern Australia.

Figs. 961-963: Cynoglossus (Cynoglossus) sealarki REGAN 1908 – 10 ×

Figs. 964-965: Cynoglossus (Cynoglossus) zanzibarensis NORMAN 1939 – 10 ×

963d

965b

965a

962

964

961

963b

965c

963c

963a

355

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Cynoglossus (Icania) maculipinnis

RENDAHL 1921

Figs. 968-969

syn. Cynoglossus maccullochi NORMAN 1926

Investigated otoliths: 2 otoliths (left and right

side), identified as C. maccullochi from Western

Australia, ZMH Ot.28.6.1995.3-4 (leg. WAM).

Discussion: Small, high otoliths with roughly

triangular outline. Cauda moderately wide, os-

tium anteriorly not narrowed. Circumsulcal de-

pression narrow.

Distribution: Western and northern Australia

and Queensland.

Cynoglossus (Icania) gilchristi REGAN 1920

Fig. 970

Investigated otoliths: 1 otolith (right side) from

the Rufiji delta, Tanzania, BMNH 1981.6.25.102-

108.

Discussion: Similar to C. maculipinnis, but with

somewhat smoothed outline of sulcus. Similar to

C. puncticeps, but less high.

Distribution: South Africa to Madagascar and

Tanzania.

Cynoglossus (Icania) puncticeps

RICHARDSON 1846

Figs. 971-975

syn. Plagusia nigrolabeculata RICHARDSON 1846

syn. Plagusia aurolimbata RICHARDSON 1846

syn. Plagusia javanica BLEEKER 1851

syn. Plagusia brachyrhynchus BLEEKER 1851

syn. Cynoglossus brevis GÜNTHER 1862

syn. Cynoglossus immaculatus PELLEGRIN &

CHEVEY 1940

Investigated otoliths: 5 otoliths ( 1 left and 4 right

side) from Singapore, ZMH Ot.28.6.1995.5-8 (leg.

BMNH 1934.11.21.1-8) and BMNH 1934.11.21.1-

Discussion: Very similar to C. gilchristi, but some-

what higher.

Distribution: From India through the Malay

Archipelago to the Philippines, the South China

Sea and Japan and southward to northwest Aus-

tralia.

Cynoglossus (Icania) leuchsi

WEINFURTER 1952

Figs. 976-980

syn. Scopelus? sp. – PRIEM 1914: fig. 8

syn. Cynoglossus leuchsi WEINFURTER 1952 –

WEINFURTER 1952: pl. 4, figs. 1-3

syn. Rhinoplagusia altus – LAFOND-GRELLETY

1967: pl. 11, fig. 52 (nomen nudum)

syn. Rhinoplagusia sp. – JONET 1973: pl. 4, fig. 137

syn. Rhinoplagusia leuchsi – JONET 1973: pl. 4,

fig. 138

syn. genus Cynoglossidarum sp. – STEURBAUT

1979: pl. 11, fig. 11

syn. Paraplagusia roseni NOLF & CAPPETTA 198

– NOLF & CAPPETTA 1980: pl. 3, figs. 19-21

syn. Paraplagusia alta STEURBAUT & JONET

1981 – STEURBAUT & JONET 1981: pl. 5,

figs. 10-13

syn.

Paraplagusia alta – STEURBAUT 1984: pl. 36,

figs. 11-14

syn. Cynoglossus altus MENZEL 1986 – MENZEL

1986: pl. 9, fig. 2, pl. 10, fig. 7

Investigated otoliths: 5 otoliths, the holotype of

C. leuchsi (fig. 977) from Wetzelsteffi near Wet-

zelsdorf, Austria, Middle Miocene, LMJ, 2 para-

types of C. leuchsi (figs. 979-980) from Mühlbauer

near St. Florian, Austria, Middle Miocene, LMJ,

the holotype of C. altus MENZEL (fig. 978) from

the well UE 12 Gräpl near Mulsum, northern

Germany, Hemmoorian, Lower Miocene, NLH

11735, 1 otolith (fig. 976) from the Hörstgen 4 shaft,

northwest Germany, Hemmoorian, Lower Mio-

cene, SMF P (coll. Anderson).

Ontogeny and variability: The small paratypes

of C. leuchsi are more gently rounded in outline,

but the predorsal projection is more strongly

developed.

Otoliths of this species vary somewhat in

outline. The postventral corner, the predorsal

projection and the postdorsal angle can all be

developed more broadly rounded or more angu-

lar. This and the wide geographic distribution of

the species in the Miocene of Europe probably is

the reason for the extended synonymy list.

356

Schwarzhans: Pleuronectiformes

Figs. 966-967: Cynoglossus (Icania) broadhursti WAITE 1905 – 10 ×

Figs. 968-969: Cynoglossus (Icania) maculipinnis RENDAHL 1921 – 10 ×

Fig. 970: Cynoglossus (Icania) gilchristi REGAN 1920 – 15 ×

Figs. 971-975: Cynoglossus (Icania) puncticeps RICHARDSON 1846 – 15 ×

967a

969b

969c

967b

968

966

970a

970b

969a

967c

971

972b

975a

972a

974

970c

973

972c

975b

357

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Discussion: Very similar to the recent C. gilchris-

ti and C. puncticeps, but usually with a more reg-

ularly curving outline.

Distribution: Lower and Middle Miocene of

Austria, France (Aquitaine and Mediterranean

Basins), Portugal and northern Germany.

Cynoglossus (Icania) cynoglossus

(HAMILTON-BUCHANAN 1822)

Fig. 981

syn. Plagusia oxyrhynchos BLEEKER 1851

syn. Plagusia sumatrana BLEEKER 1853

syn. Plagusia bengalensis BLEEKER 1853

syn. Cynoglossus hamiltonii GÜNTHER 1862

syn. Cynoglossus buchanani DAY 1869

syn. Cynoglossus deltae JENKINS 1910

Investigated otoliths: 1 otolith (right side) from

Singapore, BMNH 1933.12.27.5.

Discussion: Small, moderately compressed oto-

liths with rather flat inner face. Sulcus with ten-

dency to smoothed outline. Circumsulcal depres-

sion rather wide.

Distribution: Western India to Malay Archipel-

ago and the Philippines.

Cynoglossus (Icania) semifasciatus

DAY 1877

Fig. 982

syn. Cynoglossus brevirostris DAY 1877

Investigated otoliths: 1 otolith (right side) from

the Ganjam coast, India, BMNH 1928.3.20.107.

Discussion: Hardly distinguishable from C. cyno-

glossus by means of otoliths.

Distribution: Eastern India and Ceylon.

Cynoglossus (Icania) monopus

(BLEEKER 1849)

Fig. 983

syn. Plagusia melanopterus BLEEKER 1851

syn. Arelia ceratophrys KAUP 1858

Investigated otoliths: 1 otolith (right side) from

Singapore, BMNH 1984.1.12.91-93.

Discussion: Similar to C. cynoglossus and C. semi-

fasciatus, but unique for its extremely narrow

cauda (very low index ch:oh).

Distribution: From the Bay of Bengal through

the Malay Archipelago to Hong Kong.

Figs. 976-980: Cynoglossus (Icania) leuchsi WEINFURTER 1952 – 15 ×

976a

977b

978

977a

980

979

976b

358

Schwarzhans: Pleuronectiformes

Cynoglossus (Icania) carpentari

ALCOCK 1889

Figs. 984-989

Investigated otoliths: 6 otoliths (2 left and 4 right

side), 4 otoliths from the Bay of Bengal (figs. 984-

987), ZMH Ot.28.6.1995.9-11 (leg. BMNH 1928.

3.20.75-77) and BMNH 1928.3.20.75-77 and 2 oto-

liths from the Gulf of Oman (figs. 988-989), ZMH

Ot.28.6.1995.12-13 (leg. BMNH 1939.5.24.1799).

Discussion: Otoliths of this species are unique

amongst the genus Cynoglossus for a number of

characters. They are small (also as compared to

the size of the fishes), rather elongate, thickset,

with a flat inner face and a concave outer face.

The sulcus is reduced to a completely ovale shape,

considerably deepened and terminating at some

distance from the anterior rim of the otolith. The

circumsulcal depression is regularly curved, con-

siderably deepened and runs rather close to the

sulcus.

The otoliths of the specimen from the Gulf of

Oman (type B, figs. 988-989) differ slightly from

those of the Bay of Bengal (type A, figs. 984-987)

in being more thin and compressed and showing

an even smaller sulcus.

SMALE et al. (1995) figured otoliths of the

related species C. marleyi, wich indeed in all as-

pects closely resemble those of C. carpentari, in

particular as far as the sulcus morphology is con-

cerned. Main difference seems to be the slightly

convex inner face and the more rectangular out-

line. However, these findings further support the

special position of this little group within the

genus Cynoglossus and, in my opinion, warrants

their distinction as a distinctive subgenus.

Distribution: Persian Gulf to the Bay of Bengal,

in rather deep water.

7.9.2 Symphurus Group

Genera: One genus – Symphurus – widely dis-

tributed throughout the tropical and subtropical

world oceans in shallow to relatively deep water

on the continental shelfs and slopes.

Definition and relationship: Otoliths of the Sym-

phurus Group are typical representatives of the

family Cynoglossidae with its “hammer” shaped

sulcus. However, differing from the Cynoglossus

Group, the sulcus is somewhat reduced anterior-

ly. Further specializations are as follows. The

ventral rim is gently and regularly curving, not

very deep, whereas the dorsal rim is usually high-

er and shifted backwards. Thus the otoliths are

almost symmetrical along the horizontal axis,

which sometimes may cause difficulties to dis-

tinguish between left and right otoliths, especial-

ly when found isolated as in the fossil record.

Most notable though is the strange development

of the circumsulcal depression. It is considerably

widened and deepened postdorsally and postven-

trally (bilobate) to an extent where it almost meets

the dorsal and ventral tips of the much widened

cauda.

In most ichthyological literature Symphurus is

regarded as the plesiomorphic sister group of

Fig. 981: Cynoglossus (Icania) cynoglossus (HAMILTON-BUCHANAN 1822) – 15 ×

Fig. 982: Cynoglossus (Icania) semifasciatus DAY 1877 – 15 ×

Fig. 983: Cynoglossus (Icania) monopus (BLEEKER 1849) – 15 ×

981c

982b

981a

982a

983a

982c

981b

983b

983c

359

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Cynoglossus (and Paraplagusia), mostly because of

its not hooked and terminal snout, the still present

but rudimentary pectoral fins and the pelvic fin,

which is free from the anal fin (see MENNON,

1977 and CHAPLEAU, 1987). However, lateral

lines are absent from both sides. The otoliths in-

stead point to a completely different story. The

further and very peculiar specialization of its

morphology (see above) rather indicates Symphu-

rus to represent an apomorphic group within the

Cynoglossidae. It must be questioned if not at

least some of the seemingly plesiomorphic mor-

phological characters of the fishes rather repre-

sent some kind of secondary reduction.

Symphurus RAFINESQUE 1810

Type-species: Symphurus nigrescens RAFIN-

ESQUE 1810

syn. Odontolepis FISCHER 1813 (type-species:

S. nigrescens)

syn. Plagusia CUVIER 1816 (type-species: Pleu-

ronectes plagusia, pre-occupied)

syn. Bibronia COCCO 1844 (type-species: B. ligu-

lata)

syn. Plagiusa BONAPARTE 1846 (type-species:

P. lactea, syn. S. nigrescens, substitute for Pla-

gusia)

syn. Eupnoea GISTEL 1848 (type-species: Plagu-

sia lactea, syn. S. nigrescens)

syn. Euporista GISTEL 1848 (substitute for Plagu-

sia)

syn. Aphorista KAUP 1858 (type-species: Achirus

ornatus, syn. S. plagusia) – subgenus

syn. Glossichthys GILL 1861 (type-species: Pleu-

ronectes plagusia)

syn. Ammopleurops GÜNTHER 1862 (type-spe-

cies: Plagusia lactea, syn. S. nigrescens)

syn. Bascanius SCHIÖDTE 1867 (type-species:

B. taedifer, larval)

syn. Acedia JORDAN 1888 (type-species: Apho-

rista nebulosa)

Diagnosis: Moderately thin to thickset, high

bodied otoliths; ventral rim moderately deep and

rather regularly curving, dorsal rim usually more

high, with an inclined predorsal portion and a

massive, rounded postdorsal portion, anterior rim

broadly rounded, posterior rim high, oblique or

vertically cut, with or without concavity, or broad-

ly rounded. Otoliths small, up to 3 mm.

Sulcus usually shallow, occasionally slightly

deepened, with fused colliculi, typical “hammer”

shaped outline, often with smoothed outline,

anteriorly reduced. Circumsulcal depression well

developed, narrow, often furrow like, postdor-

sally and postventrally widened to nearly reach

the dorsal and ventral tips of the cauda (bilo-

bate), running close to the otolith rims.

Inner face moderately convex to nearly flat,

usually rather smooth; outer face flat to marked-

ly convex, usually smooth. Rims moderately

sharp, sometimes thickset, not or only faintly

ornamented.

Subgeneric definitions: So far otoliths have only

be investigated from 15 species of the extant 72

nominal species of the genus. It may thus seem

premature to formulate a detailed analysis of

morphological clusters observed. Anyhow, oto-

liths of those species investigated fall into two

quite well defined groups characterized in the

following. However, more material should be

awaited of additional species to support this con-

cept once they get available or other ichthyolog-

ical investigations to verify this grouping. Tenta-

tively, the two distinctive groups are assigned to

subgeneric ranking with names taken from the

generic synonymy list.

One group is characterized by very high oto-

liths with an outline as described in the above

diagnosis. Also, they are usually quite thin and

their sulcus is rather large. These species are placed

in the formal subgenus Aphorista. So far, this pat-

tern has only be found in new world species.

The second group of species is placed in the

formal subgenus Symphurus. These otoliths have

an almost perfectly round outline. They are much

more thickset and show a tendency to reduce the

size of the sulcus. The latter is carried furthest in

S. gilesi and S. nigrescens. The majority of species

placed in this group are from the old world, but

few new world species are tentatively included

as well. With more material coming at hand it

could be envisaged that this group is being split

up further. Candidates for this are the two spe-

cies mentioned above.

The features separating the subgenus Sym-

phurus from Aphorista are mainly due to reduc-

tion of certain characters. They are therefore

thought to represent a more derived group.

360

Schwarzhans: Pleuronectiformes

Measurements:

l:h h:t l:ol ch:oh con.i

subgenus Aphorista

plagusia 0.95 4.0 2.0 2.4 3.5

elongatus 0.85 4.4 2.1 2.5 4.4

chabanaudi 0.85 3.6 2.1 2.4 3.2

plagiusa 0.75 nm 1.9 3.5 nm

trewavasae 0.90-1.00 2.9 1.8-2.3 2.1-2.4 5.2

civitatus 0.90-0.95 3.4 1.9-2.1 2.2-2.4 2.9

oculellus 1.00 3.6 2.4 3.6 3.5

leei 0.90-0.95 3.8 2.0-2.2 2.5 4.3

atricaudus 0.85-0.90 2.8-3.0 1.8-2.2 1.7-2.4 2.8

subgenus Symphurus

williamsi 1.10 2.3 2.4 2.5 2.4

atramentatus 1.10 2.7 2.6 1.8 3.0

orientalis 1.00-1.05 2.0 2.7-2.8 2.8 2.2

septemstriatus 0.95-1.00 2.9 2.6-2.8 1.5-1.8 5.5

gilesi 0.95 nm 3.2 1.8 nm

nigrescens 1.00-1.05 2.8 2.8-2.9 nm 3.3

Side dimorphism: Usually not apparent. Occa-

sional, otoliths of the left side show a slightly less

high cauda.

Variability: The variability level in the species of

this genus apparently is quite different. In most

species it seems to be very moderate and then

distinction of even closely related species may

not be very difficult. Few species, however, show

extreme variations of the outline. S. atricaudatus

is such a species with a very irregular outline. In

such cases it becomes very difficult to find diag-

nostic characters on the species level.

Discussion: As stated before (see entry to Cy-

noglossidae and the Symphurus Group) otoliths

of the genus Symphurus are characterized by a

number of autapomorphic features, such as the

anteriorly reduced sulcus, the bilobate circum-

sulcal depression and the backwardly shifted

dorsal rim. Some of these characters are to cer-

tain extent foreshadowed in some members of

the genus Cynoglossus (subgenus Cynoglossus). I

therefore regard Symphurus as the more derived

genus in the Cynoglossidae.

Species and distribution: Unlike the genus Cy-

noglossus, Symphurus has so far not been subject

to a comprehensive revision, although a number

of regional revisions have been published

(CHABANAUD 1956, GINSBURG 1951, MEN-

EZES & BENVEGNU 1976, MUNROE 1990, 1991).

There may be up to 72 nominally valid recent

species in this genus and new species are con-

stantly being described. Apparently, the high

number of species is due to a very pronounced

regionalization of the species in this genus. Also

many species seem to be established on few spec-

imens only and are difficult to come by for otolith

extraction (hence only 15 species represented

here). Furthermore, it was found while extract-

ing otoliths from specimens of Symphurus that

they were often dissolved by formalin. Possibly

Figs. 984-989: Cynoglossus (Icania) carpentari ALCOCK 1889;

figs. 984-987 morphotype A, figs. 988-989 morphotype B – 15 ×

987c

989b

987a

988a

989a

989c

987b

986b

986c

985

984

986

361

Piscium Catalogus, Part Otolithi piscium, Vol. 2

they act more sensitive to formalin than those of

other Pleuronectiformes.

72 nominally valid species are listed in the

following (new and old world species listed sep-

arately). The list may not be complete.

New world species: S. arawak, S. atramentatus,

S. atricaudus, S. bergi, S. callopterus, S. caribbeanus,

S. chabanaudi, S. civitatum, S. diabolicus, S. dio-

medianus, S. elongatus, S. fasciolaris, S. ginsburgi,

S. gorgonae, S. jenynsi, S. kyaropterygium, S. leei, S.

luzonensis, S. marginatus, S. melanurus, S. melas-

matotheca, S. meridionalis, S. microlepis, S. minor,

S. nebulosus, S. oculellus, S. oligomerus, S. omma-

spilus, S.paitensis, S. parvus, S. pelicanus, S. piger,

S. plagiusa, S. plagusia, S. prolatinaris, S. pterospi-

lotus, S. pusillus, S. rhytisma, S. sumtuosus,

S. tesselatus, S. trewavasae, S. undatus, S. undecim-

plerus, S. urospilos, S. varius, S. williamsi.

Old world species: S. arabicus, S. australis, S.

fallax, S. fuscus, S. gilesi, S. holothuriae, S. ligulatus,

S.lubbocki, S. macrophthalmus, S. maldiviensis,

S. marmoratus, S. nigrescens, S. normani, S. novem-

fasciatus, S. ocellatus, S. orientalis, S. regani, S. reticu-

latus, S. sayademalhensis, S. schultzi, S. sep-

temstriatus, S. strictus, S. trifasciatus, S. variegatus,

S. vittatus, S. woodmasoni.

In the fossil record Symphurus otoliths have

rarely been reported. Two specimens reported

from the Miocene of Trinidad (NOLF, 1976) and

the Miocene of the Dominican Republic (NOLF

& STRINGER, 1992) are too poorly preserved for

specific identification. A single specimen from the

Pliocene of northern Morocco is tentatively as-

signed to the recent S. nigrescens.

Symphurus (Aphorista) plagusia

(BLOCH & SCHNEIDER 1801)

Fig. 990

syn. Achirus ornatus LACEPEDE 1803

Investigated otoliths: 1 otolith (right side) from

Trinidad (identified as S. ornatus), BMNH 94.5.8.6.

Discussion: An otolith with a rather regularly

curving outline and a rather large sulcus.

Distribution: West Indies, south to Rio de Janei-

ro, in shallow water.

Fig. 990: Symphurus (Aphorista) plagusia (BLOCH & SCHNEIDER 1801) – 10 ×

Fig. 991: Symphurus (Aphorista) elongatus (GÜNTHER 1869) – 10 ×

Figs. 992-993: Symphurus (Aphorista) chabanaudi MAHADEVA & MUNROE 1990– 10 ×

Fig. 994: Symphurus (Aphorista) plagiusa (LINNAEUS 1766) – 10 ×

992c

992d

992a

990b

990a

990d

992b

991b

991d

994

993

991c

990c

991a

362

Schwarzhans: Pleuronectiformes

Symphurus (Aphorista) elongatus

(GÜNTHER 1869)

Fig. 991

Investigated otoliths: 1 otolith (right side), ZMH

Ot. 4.7.1995.1 (leg. ZMH 20195).

Discussion: A thin otolith with a straight, verti-

cally cut posterior rim and a markedly concave

predorsal rim.

Distribution: Pacific coast of tropical America.

Symphurus (Aphorista) chabanaudi

MAHADEVA & MUNROE 1990

Figs. 992-993

Investigated otoliths: 2 otoliths (right side), para-

types from the Gulf of California, ZMH Ot.4.7.

1995.2 (leg. BMNH 1956.3.1.6-14) and BMNH

19563.1.6-14.

Discussion: Very similar to S. plagusia but some-

what more compressed.

Distribution: Gulf of California.

Symphurus (Aphorista) plagiusa

(LINNAEUS 1766)

Fig. 994

syn. Plagusia fasciata HOLBROOK 1842

Investigated otoliths: 1 somewhat eroded oto-

lith (right side) from Rockport, USA, BMNH

1948.8.6.1374.

Discussion: Extremely high and rather thickset

otolith with an almost triangular sulcus outline.

Distribution: South Atlantic and Gulf coast of

the USA.

Symphurus (Aphorista) trewavasae

CHABANAUD 1948

Figs. 995-999

Investigated otoliths: 5 otoliths (1 left side and

4 right side), paratypes from Rio de Janeiro, Bra-

zil, ZMH Ot. 4.7.1995.3-6 (leg. BMNH 1913.12.

4.264-73) and BMNH 1913.12.4.264-73.

Discussion: Otoliths with a distinctly concave

predorsal rim and a bluntly rounded posterior

rim similar to S. elongatus, but more thickset and

with a rather narrow cauda.

Distribution: Atlantic coast of South America.

Figs. 995-999: Symphurus (Aphorista) trewavasae CHABANAUD 1948 – 10 ×

996

999

997

998b

998d

998c

995

998a

363

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Symphurus (Aphorista) civitatum

GINSBURG 1951

Figs. 1000-1001

Investigated otoliths: 2 otoliths (right side) from

Louisiana, USA, ZMH Ot.4.7.1995.7 (leg. BMNH

1931.11.5.76-81( and BMNH 1931.11.5.76-81.

Discussion: Similar to S. trewavasae, but without

concave predorsal rim, with a pointed postdorsal

angle and e regularly deepened sulcus.

Distribution: Gulf coast, USA and Mexico, Ber-

mudas, in moderately deep water.

Symphurus (Aphorista) oculellus

MUNROE 1991

Fig. 1002

Investigated otoliths: 1 otolith (right side), para-

type from British Guyana, 8°30’N/59°02’W,

BMNH 1961.9.4.117-118.

Discussion: Similar to S. civitatum, but less com-

pressed and with a somewhat pointed anterior

tip.

Distribution: Guyana and northeastern Brazil,

in moderately deep water.

Symphurus (Aphorista) leei

JORDAN & BOLLMAN 1889

Figs. 1003-1004

Investigated otoliths: 2 otoliths (left and right

side) from the Pacific coast of Panama, ZMH

Ot.4.7.1995.8 (leg. BMNH 1930.9.2.41) and BMNH

1930.9.2.41.

Discussion: Very similar to S. oculellus and pos-

sibly an allopatric species, but more compressed.

S. leei is also one of the few species of the genus

in which an incipient side dimorphism of the

otoliths could be observed.

Distribution: Pacific cost of Columbia and Pan-

ama.

Symphurus (Aphorista) atricaudus

JORDAN & GILBERT 1880

Figs. 1005-1009

Investigated otoliths: 6 otoliths (3 left side and

3 right side) from southern California, ZMH

Ot.4.7.1995.9-14 (leg. Fitch).

Discussion: Rather thickset, high otoliths with a

rather narrow sulcus and an extremely irregular

outline.

S. atricaudus is one of the species within this

genus with a very wide range in morphological

variations, in particular as the outline is con-

cerned.

Distribution: California, USA.

Figs. 1000-1001: Symphurus (Aphorista) civitatum GINSBURG 1951 – 10 ×

Fig. 1002: Symphurus (Aphorista) oculellus MUNROE 1991 – 10 ×

1000c

1001

1000d

1002b

1002a

1000b

1000a

1002c

1002d

364

Schwarzhans: Pleuronectiformes

Symphurus (Symphurus) williamsi

JORDAN & CULVER 1895

Fig. 1010

Investigated otoliths: 1 otolith (right side), To-

bago Isl., Pacific coast of Panama, BMNH 1926.7.

12.77-78.

Discussion: A roundish, rather thickset otolith

with still a rather large sulcus.

Distribution: Pacific coast of Mexico, south to

Panama.

Symphurus (Symphurus) atramentatus

JORDAN & BOLLMAN 1889

Fig. 1011

Investigated otoliths: 1 otolith (right side) from

Lower California, BMNH 1930.9.2.38.

Discussion: Very similar to S. williamsi and prob-

ably a sympatric species, but may be somewhat

more thin.

Distribution: Pacific coast of tropical America

from Lower California to Colombia.

Figs. 1003-1004: Symphurus (Aphorista) leei JORDAN & BOLLMAN 1889 – 15 ×

Figs. 1005-1009: Symphurus (Aphorista) atricaudus JORDAN & GILBERT 1880 – 10 ×

1005c

1003

1004d

1004b

1005a

1005b

1004a

1004c

1006c

1006a

1006b

1008

1007a

1007b

1009

365

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Symphurus (Symphurus) orientalis

(BLEEKER 1879)

Figs. 1012-1013

Investigated otoliths: 2 otoliths (left and right

side) from off Kochi, Japan, ZMH Ot.4.7.1995.15-

16 (leg. Sasaki).

Discussion: Very thickset, regularly round oto-

liths with a small sulcus and a rather convex in-

ner face.

Distribution: Japan.

Symphurus (Symphurus) septemstriatus

(ALCOCK 1891)

Figs. 1014-1015

Investigated otoliths: 2 otoliths (left and right

side) from off Colombo, Ceylon, ZMH

Ot.4.7.1995.17 (leg. BMNH 1928.3.20.72 and

BMNH 1928.3.20.72.

Discussion: Thickset, less well rounded and high

otoliths with a very small sulcus and a flat inner

face.

Distribution: Ceylon and Andaman Islands.

Fig. 1010: Symphurus (Symphurus) williamsi JORDAN & CULVER 1895 – 15 ×

Fig. 1011: Symphurus (Symphurus) atramentatus JORDAN & BOLLMAN 1889 – 10 ×

Figs. 1012-1013: Symphurus (Symphurus) orientalis (BLEEKER 1879) – 15 ×

Figs. 1014-1015: Symphurus (Symphurus) septemstriatus (ALCOCK 1891) – 15 ×

Fig. 1016: Symphurus (Symphurus) gilesi (ALCOCK 1889) – 15 ×

1011c

1014

1010d

1010b

1012

1013c

1010a

1010c

1013d

1011a

1011b

1015b

1013a

1013b

1015a

1016

1015c

1015d

366

Schwarzhans: Pleuronectiformes

Symphurus (Symphurus) gilesi

(ALCOCK 1889)

Fig. 1016

Investigated otoliths: 1 somewhat eroded oto-

lith (left side), from the Gulf of Aden, BMNH

1939.5.24.1827-34.

Discussion: Very similar to S. septemstriatus (also

with flat inner face), but with rather shallow

dorsal rim and an extremely small sulcus.

Distribution: Gulf of Aden, Bay of Bengal, Kei

Islands, lower shelf.

Symphurus (Symphurus) nigrescens

RAFINESQUE 1810

Figs. 1017-1021

syn. Plagusia lactea BONAPARTE 1833

syn. Plagusia picta COSTA 1862

Investigated otoliths: 5 otoliths (2 left and 3 right

side), 3 otoliths (figs. 1017, 1018, 1021) from Bou

Aioun, Algeria, ZMH Ot.4.7.1995.18-20 (leg.

BMNH 1950.2.8.1-5), 2 otoliths (figs. 1019-1020)

from the Bay of Biscay, ZMH Ot.4.7.1995.21 (leg.

BMNH 90.6.16.46) and BMNH 90.6.16.46.

Discussion: Roundish otoliths with a somewhat

narrowed dorsal rim and a very small sulcus with

rather regular outline, anteriorly pointed.

Distribution: Mediterranean, East-Atlantic from

France to Angola, in rather deep water.

Figs. 1017-1021: Symphurus (Symphurus) nigrescens RAFINESQUE 1810 – 15 ×

1020c

1018d

1018b

1020a

1019

1018c

1017

1021

1018a

1020b

367

Piscium Catalogus, Part Otolithi piscium, Vol. 2

AMAOKA, K. (1969): Studies on the sinistral flounders

found in the waters around Japan. Taxonomy, anat-

omy and phylogeny. – J. Shimonoseki Univ. Fish.,

18: 65-340.

⎯ (1972): Osteology and relationships of the Citharid

flatfish Brachypleura novaezeelandiae. – Japanese

Journ. Ichthyol., 19: 263-273; Tokyo.

BAUZA-RULLAN, J. (1958): Otolitos de peces actu-

ales. – Bol. Roy. Soc. Espan. Hist. natur., 56: 111-126;

Madrid.

BLACHE, J., CADENAT, J. & STAUCH, A. (1970): Clés

de détermination des poissons de mer signalés dans

l’Atlantique oriental. – O.R.S.T.O.M., Paris: 1-479.

BÖHLKE, J. E. & CHAPLIN, C. C. (1993): Fishes of the

Bahamas and adjacent tropical waters. – Univ. Tex-

as Press, Austin: 1-771.

CHABANAUD, P. (1928): Revision des poissons Hétéro-

somes de la sous-famille des Achirinae, d’aprés les

types de Kaup, de Günther et de Steindachner. –

Bull. Inst. Oceanogr., 523: 1-53; Monaco.

⎯ (1930): Les genres de poissons Hétérosomates (Pis-

ces Heterosomata) appartenant à la sous-famille des

Soleinae. – Bull. Inst. Oceanogr., 555: 1-22; Monaco.

⎯ (1931): Sur divers poissons Soléiformes de la ré-

gion Indo-Pacifique. – Bull. Soc. Zool. France, 56:

291-305; Paris.

⎯ (1934): Les Soléidés du groupe Zebrias, définition

d’un sous-genre nouveau et description d’une sous-

espèce nouvelle. – Bull. Soc. Zool. France, 59: 420-

436; Paris.

⎯ (1938): Sur un très rare Achiridé du bassin de l’Ama-

zone. – Bull. Soc. Zool. France, 63: 200-211; Paris.

⎯ (1939): Catalogue systématique et chorologique des

Téléostéens dyssymétriques du globe. – Bull. Inst.

Oceanogr., 763: 1-31; Monaco.

⎯ (1948): Morphologie et systématique des soléides

affectés d’une atropie plus on moins complète de

l’oeil migrateur. – Zool. Verhand., Rijksmus. Natu-

ur. Hist. Leiden, 3: 1-58.

⎯ (1949): Le problème de la phylogenèse des Hetero-

somata. – Bull. Inst. Oceanogr., 950: 1-24; Monaco.

⎯ (1949): Contribution à l’anatomie et à la systéma-

tique de la famille des Bothidae, s.str. – Bull. Soc.

Zool. France, 74: 246-253; Paris.

⎯ (1949): Téléostéens dissymétriques (Heterosomata).-

In: Résultats scientifiques des croisiéres du naviere-

école Belge “Mercator”. – Mem. Inst. Roy. SWci.

Natur. Belg., 33; Brussels.

⎯ (1955): Rectifications affèrentes à la nomenclature

et à la systématique des Pleuronectiformes du sous-

ordre des Soleoidei. – Bull. Mus. nat. Hist. natur.,

27: 447-452; Paris.

⎯ (1956): Les Symphurus marbrés du complexe Indo-

Pacifique tropical. – Arch. Mus. Nat. Hist. Natur., 7:

79-100; Paris.

CHAINE, J. (1936): Recherches sur les otolithes des

poissons, Etude descriptive et comparative de la

sagitta des téléostéens; 3. – Act. Soc. Linnéenne

Bordeaux, 88: 1-246, pl.I-XV.

CHAPLEAU, F. (1987): Comparative osteology and

intergeneric relationships of the tongue soles (Pis-

ces; Pleuronectiformes; Cynoglossidae). – Can. J.

Zool., 66: 1214-1232.

⎯ (1993): Pleuronectiform relationships: a cladistic

reassessment. – Bull. Marine Sci., 52: 516-540; Coral

Gables, Florida.

CHAPLEAU, F. & KEAST, A. (1988): A phylogenetic

reassessment of the monophyletic status of the fam-

ily Soleidae, with notes on the suborder Soleoidei. –

Can. J. Zool., 66: 2797-2810.

CHIRICHIGNO, N. (1974): Clava para identificar los

peces marinos del Peru. – Inst. del mar del Peru, 44:

reprinted 1978, Otto Koeltz Verl.: 1-387; Koenigstein.

DESOUTTER, M. (1990): Soleidae. In: Check list of the

fishes of the Eastern Tropical Atlantic (QUERO, J.

C., ed.). – UNESCO, 1037-1049; Paris.

⎯ (1994): Révision des genres Microchirus, Dicologlos-

sa et Vanstraelenia (Pleuronectiformes, Soleidae). –

Cybium, 18: 215-249; Paris.

ESCHMEYER, W. N. (1990): Catalog of the genera of

recent fishes. – California Acad. Sci., 1-697; San Fran-

cisco.

EVSEENKO, S. A. (1984): A new genus and species of

lefteye flounder, Pseudomancopsetta andriashevi, and

their position in the suborder Pleuronectoidei. – Vop.

Ikhtiol., 24: 709-717.

FRASER, T. H. (1971): Notes on the biology and system-

atics of the flatfish genus Syacium (Bothidae) in the

straits of Florida. – Bull. marine sci., Univ. Miami,

Marine Lab., 21: 491-509; Coral Gables, Florida.

FROST, E. A. (1930): A comparative study of the otoliths

of the Neopterygian fishes; part XIII. – Ann. Mag.

Nat. Hist., 10: 231-239; London.

FUTCH, C. R. (1977): Larvae of Trichopsetta ventralis,

with comments on the intergeneric relationships

within the Bothide. – Bull. marine sci., Univ. Miami,

Marine Lab., 27: 740-757; Coral Gables, Florida.

GINSBURG, I. (1951): Western Atlantic tonguefishes

with descriptions of six new species. – U.S. Fish &

Wildlife Serv., 36: 185-201; Washington.

⎯ (1952): Flounders of the genus Paralichthys and relat-

ed genera in American waters. – Fish. Bull Fish &

Wildlife Serv., 52, Fishery Bull., 71: 267-351;

Washington.

8. Selected literature

Recent fishes

(Includes major references which deal with Pleuronectiformes, regional faunal lists or publications which

include figures of recent Pleuronectiform otoliths or other references of recent otoliths cited in the text)

368

Schwarzhans: Pleuronectiformes

GLOERFELT-TARP, T. & KAILOLA, P. J. (1984): Trawled

fishes of southern Indonesia and northwestern

Australia. – Tien Wah Press: 1- 406; Singapore.

GOODE, G. B. & BEAN, T. H. (1883): Reports on the

results of dredging, under the supervision of Alex-

ander Agassiz, on the East coast of the United States,

during the summer of 1880, by the U S Coast Sur-

vey steamer “Blake”, Commander J R Bartlett, U S

N, commanding. – Bull. Mus. comp. Zool., 10:

183-226; Harvard.

GON, O. & HEEMSTRA, P. C. (1990): Fishes of the south-

ern ocean. – J.L.B. Smith Inst. Ichthyol., Graham-

stown: 1-462.

HENSLEY, D. A. (1977): Larval development of Engyo-

phrys senta (Bothidae), with comments on intermus-

cular bones in flatfishes. – Bull. Mar. Sci., 27: 681-

703; Washington.

HENSLEY, D. A. & AHLSTROM, E. H. (1984): Pleu-

ronectiformes.- In: Ontogeny and systematics of

fishes. – Amer. Soc. Ichthyol. Herpetol., Spec. Pub.

1: 670-687; Lawrence, Canada.

HUBBS, C. L. (1945): Phylogenetic position of the Cith-

aridae, a family of flatfishes. – Misc. Pub., Mus.

Zool., Univ. Michigan, 23: 1-38; Ann Arbor.

JAMES, G. D. (1972): Revision of the New Zealand flat-

fish genus Peltorhamphus with descriptions of two

new species. – Copeia, 2: 345-355.

JORDAN, D., EVERMANN, B. & CLARK, H. (1930):

Check list of the fishes and fishlike vertebrates of

North and Middle America north of the northern

boundary of Venezuela and Columbia. – Reprinted

1955; Rep. United States Commissioner Fish., App.

X: 1-670.

KOTTHAUS, A. (1977): Fische des Indischen Ozeans.

Ergebnisse der ichthyologischen Untersuchungen

während der Expedition des Forschungsschiffes

“Meteor” in den Indischen Ozean, Oktober 1964

bis Mai 1965; Teil XX: Pleuronectiformes (Hetero-

somata). – “Meteor” Forsch.-Ergebnisse, Reihe D,

26: 1-20; Berlin, Stuttgart.

LAUDER, G. V. & LIEM, K. F. (1983): The evolution and

interrelationships of the Actinopterygian fishes. –

Bull. Mus. Comp. Zool., 150: 95-197; Cambridge,

Mass.

MASUDA, H., AMAOKA, K., ARAGA, C., UYENO, T.

& YOSHIMO, T. (1984): The fishes of the Japanese

Archipelago. – Tokai University Press; Tokio.

MENON, A. G. (1977): A systematic monograph of the

tongue soles of the genus Cynoglossus Hamilton-

Buchanan (Pisces: Cynoglossidae). – Smithsonian

Contrib. Zool., 238: 1-129; Washington.

⎯ (1979): A revision of the fringed-lip tongue soles of

the genus Paraplagusia Bleeker, 1865 (family Cy-

noglossidae). – Matsya, 5: 11-22; Madras.

MENEZES, N. & BENVEGNU, G. de Q. (1976): On the

species of the genus Symphurus from the Brazilian

coast, with descriptions of two new species (Os-

teichthys, Pleuronectiformes, Cynoglossidae). – Pap.

Avulsos Dept. Zool., 30: 137-170; Sao Paulo.

MUNROE, T. A (1990): Eastern Atlantic tonguefishes

(Symphurus: Cynoglossidae, Pleuronectiformes)

with descriptions of two new species. – Bull. Ma-

rine. Sci., 47: 464-515; Coral Gables, Florida.

⎯ (1991): Western Atlantic tonguefishes of the Symphu-

rus plagusia comples, with descriptions of two new

species. – U.S. Fishery Bull., 89: 247-287; Washington.

NELSON, J. P. (1984): Fishes of the world; 2nd edition.

– John Wiley & sons, New York: 1-523.

⎯ (1994): Fishes of the world; 3rd edition. – John Wiley

& sons, New York: 1-600.

NIELSEN, J. (1961): Atlantide Report No. 6. Psettodoi-

dea and Pleuronectoidea (Pisces, Heterosomata). –

Danish Science Press, Copenhagen: 101-129.

⎯ (1961): Galathea Reports Vol. 4. Heterosomata (Pis-

ces). – Dan. Sci. Press: 219-227; Copenhagen.

⎯ (1963): Atlantide Report No. 7. Soleoidea (Pisces,

Heterosomata). – Danish Science Press, Copenha-

gen: 7-36.

⎯ (1963): Notes on some Heterosomata (Pisces) from

N-W South America with the description of a new

genus and species and a new subspecies of Para-

lichthinae. – Vidensk. Medd. fra Dansk naturh.

Foren., 125: 377-405; Copenhagen.

⎯ (1963): Description of two large unmetamorphosed

flatfish-larvae (Heterosomata). – Vidensk. Medd. fra

Dansk naturh. Foren., 125: 401-407; Copenhagen.

⎯ (1964): Heterosomata (Pisces) collected by dr. Th.

Mortensen off South Africa. – Vidensk, Medd. fra

Dansk naturh. Foren., 127: 127-135; Copenhagen.

NORMAN, J. R. (1934): A systematic monograph of the

flatfishes (Heterosomata); Vol. 1: Psettodidae, Both-

idae, Pleuronectidae. – The Trustees of the British

Museum, London: 1-459

⎯ (1937): Coast fishes. Part II. The Patagonian region. –

Discovery Reports, 16: 1-150.

⎯ (1939): The John Murray expedition 1933-34 scien-

tific reports; vol. VII: zoology. – Brit. Mus. (Nat.

Hist.): 1-116; London.

OCHIAI, A. (1963): Soleina (Pisces). – Fauna Japonica;

Biogeogr. Soc. Japan, Nat. Sci. Mus.: 1-114; Tokyo.

OHE, F. (1985): Marine fish-otoliths of Japan. – Bull.

Senior High School Aichi Univ. Educ., Spec. Vol., 1-

184; Hirosawa.

PARKER, G. H. (1903): The optic chiasma in Teleosts

and its bearing on the asymmetry of the Hetero-

somata (flatfishes). – Bull. Mus. Comp. Zool., 40:

221-242; Cambridge, Mass.

PAULIN, C., STEWART, A., ROBERTS, C. & MC MIL-

LAN, P. (1989): New Zealand fish. A complete

guide. – Nat. Mus. N.Z. Misc. Ser. 19, Wellington.

QUERO, J.-C., HENSLEY, D. A. & MAUGÉ, A. L. (1989):

Pleuronectidae de l’ile de la Réunion et de Mada-

gascar; II. Genres Samaris et Samariscus. – Cybium,

13: 105-114; Paris.

REGAN, C. T. (1910): The origin and evolution of the

teleostean fishes of the order Heterosomata. – Ann.

Mag. Nat. Hist., 6: 484-496; London.

369

Piscium Catalogus, Part Otolithi piscium, Vol. 2

SAKAMOTO, K. (1984): Interrelationships of the fam-

ily Pleuronectidae (Pisces: Pleuronectiformes). –

Mem. Fac. Fish. Hokkaido Univ., 31: 95-215; Hoka-

date.

SCHWARZAHNS, W. (1978): Otolith-morphology and

its usage for higher systematical units, with special

reference to the Myctophiformes s.l. – Meded.

Werkgr. Tert. Kwart. Geol., 15: 167-185; Rotterdam.

⎯ (1993): A comparative morphological treatise of

recent and fossil otoliths of the family Sciaenidae

(Perciformes). – Verl. Dr. F. Pfeil, Piscium Catalo-

gus, Otolithi Piscium, 1: 1-245; München.

⎯ (1994): Sexual and ontogenetic dimorphism in oto-

liths of the family Ophidiidae. – Cybium, 18: 71-98;

Paris.

SCOTT, T. D., GLOVER, C. J. & SOUTHCOTT, R. V.

(1974): The marine and freshwater fishes of South

Australia. – A.B.James Govn. Print.: 1-392; Adelaide.

SHEN, S.-C. (1984): Coastal fishes of Taiwan. – Dept.

Zool. Nat. Taiwan Univ., Taipei: 1-190.

SMALE, M. J., WATSON, G. & HECHT, T. (1995): Oto-

lith atlas of the southern African marine fishes. -

Ichthyological Monographs of the J. L. B. Smith In-

stitute of Ichthyology, 1: 1-253, Grahamstown.

SMITH, M. M. & HEEMSTRA, P. C. (1986; ed.): Smith’s

sea fishes. – Springer Verl., Berlin: 1-1047.

STAUCH, A. & BLANC, M. (1964): Dageichthys lakdon-

ensis, Téléostéen pleuronectiforme du bassin de la

Haute-Bénoué. – Bull. Mus. Nat. Hist. Natur., 36:

172-177, Paris.

TOPP, R. W. & HOFF, F. H. (1972): Memoirs of the

Hourglass cruises; flatfishes (Pleuronectiformes). –

Marine Res. Lab. Florida Dept. Natur. Resources,

St. Petersburg, Florida, vol. IV, part II: 1-135.

TORCHIO, M. (1973): Soleidae. In: Check list of the

fishes of the northeastern Atlantic and the Mediter-

ranean (HUREAU, J. C. & MONOD, T., eds.). –

UNESCO: 628-634; Paris.

WEBER, M. & DE BEAUFORT, L. F. (1929): Fishes of the

Indo-Australian Archipelago. Vol. 5. – Brill, Leiden.

WHITEHEAD, P. J., BAUCHOT, M.-L., HUREAU, J.-

C., NIELSEN, J. & TORTONESE, E. (1986): Fishes

of the North-eastern Atlantic and the Mediterrane-

an; Vol. III. – UNESCO, Paris: 1015-1473.

WHITLEY, G. P. (1968): A check-list of the fishes record-

ed from the New Zealand region. – The Australian

Zoologist, 15: 1-102; Sydney.

Fossil fishes

(Includes references of fossil pleuronectiform otoliths and other fossil otoliths cited in the text)

ANDREWS, S. M., GARDINER, B. G., MILES, R. S. &

PATTERSON, C. (1967): Pisces. In: The fossil

record. – Geol. Soc. London, 637-683.

ANFOSSI, G. & MOSNA, S. (1979): La fauna ittiologica

di Monte Roero (Alba, Italia NW), Otoliti. – Atti.

Ist. Geol. Univ. Pavia, 27: 111-132; Pavia.

BASSOLI, G. (1906): Otoliti fossili terziari dell’ Emilia.

– Riv. Ital. Paleontol., 12: 36-58; Perugia.

BAUZA-RULLAN, J. (1955): Contribucion al cono-

cimiento de la fauna ictiologica fosil de Espana. –

Bol. Soc. Hist. natur. Baleares, 1: 71-80; Palma de

Mallorca.

CHANET, B. & SCHULTZ, O. (1994): Pleuronectiform

fishes from the Upper Badenian (Middle Miocene)

of St. Margarethen (Austria). - Ann. Naturhist. Mus.

Wien, 96A: 95-115; Wien.

DANTE, J. & FRIZZELL, D. (1965): Otoliths of some

early cenozoic fishes of the Gulf Coast. – J. Paleon-

tol., 39: 687-718.

FITCH, J. (1964): The fish fauna of the Playa Rey loacal-

ity, a southern California marine Pleistocene de-

posit. – Los Angeles County Mus. Contrib. Sci., 82:

3-35; Los Angeles.

⎯ (1966): Additional fish remains, mostly otoliths,

from a Pleistocene deposit at Playa del Rey, Califor-

nia. – Los Angeles County Mus. Contrib. Sci., 119:

1-16; Los Angeles.

⎯ (1967): The marine fish fauna, based primarily on

otoliths of a Lower Pleistocene deposit at San Pedro,

California (LACMIP 332, San Pedro Sand). – Los

Angeles County Mus. Contrib. Sci., 128: 1-23; Los

Angeles.

⎯ (1968): Otoliths and other fish remains from the

Timms Point Silt (Early Pleistocene) at San Pedro,

California. – Los Angeles County Mus. Contrib. Sci.,

146: 1-29; Los Angeles.

⎯ (1970): Fish remains, mostly otoliths and teeth, from

the Palos Verdes Sand (Late Pleistocene) of Califor-

nia. – Los Angeles County Mus. Contrib. Sci., 199:

1-41; Los Angeles.

FITCH, J. & LAVENBERG, R. (1981): Teleost fish oto-

liths from Lee Creek Mine, Aurora, North Carolina

(Yorktown Formation: Pliocene). – Smithsonian

Contrib. Paleobiol., 53: 509-529; Washington.

FITCH, J: & REIMER, R. (1967): Otoliths and other fish

remains from a Long Beach, California, Pliocene

deposit. – Bull. S. California Acad. Sci., 66: 77-91;

Los Angeles.

FROST, E. A. (1925): Description of fish otoliths from

the Tertiary formations of Atcheen, North Sumat-

ra. – Dienst Mijnb. Nederl. Oost-Indie, Weten. Med-

ed., 2: 1-28; Weltevreden.

⎯ (1934): Otoliths of fishes from the Lower Tertiary

formations of Southern England. Part V: Anacan-

370

Schwarzhans: Pleuronectiformes

thini, Heterosomata, Ostariophysi. – Ann. Mag. nat.

Hist., 14: 500-505; London.

GAEMERS, P. A. M. (1972): Otoliths from the type lo-

cality of the Sands of Berg (Middle Oligocene) at

Berg, Belgium. – Meded. Werkgr. Tert. Kwart. Geol.,

9: 73-85; Leiden.

⎯ (1974): Otolieten uit het Merksemien en Icenien van

Boring Ouwerkerk (Zeeland, Nederland). – Med-

ed. Werkgr. Tert. Kwart. Geol., 11: 133-143; Leiden.

GAEMERS, P. A. M. & SCHWARZHANS, W. (1973):

Fisch-Otolithen aus dem Pliozän von Antwerpen

(Belgien) und Ouwerkerk (Niederlande) und aus

dem Plio-Pleistozän der Westerschelde (Nieder-

lande). – Leidse Geol. Meded., 49: 207-257; Leiden.

⎯ & ⎯ (1982): Fisch-Otolithen aus der Typusloka-

lität der obermiozänen Sylt-Stufe (Morsum-Kliff,

Insel Sylt, Nordwestdeutschland). – Leidse Geol.

Meded., 52: 119-177; Leiden.

GRENFELL, H. (1984): Early Miocene teleost otoliths

from Parengarenga Harbour, New Zealand. – NZ J.

Geol. Geophys., 27: 51-96; Wellington.

HATAI, K. (1965): Some Pliocene fish otoliths from Ja-

pan. – Senckenbergiana lethaea, 46a: 133-143; Frank-

furt/M.

HEINRICH, W.-D. (1968): Fischotolithen aus dem Ober-

miozän von Hohen Woos. – Z. Gesamtgeb. geol.

Wiss., 18: 1-111; Berlin.

⎯ (1970): Nachweis der Teleosteergattung Lepidorhom-

bus Günther, 1862 im Chatt von Malliß. – Geologie,

19: 883-887; Berlin.

JONET, S. (1973): Etude des otolithes des téléostéens

(pisces) du Miocène des environs de Lisbonne. –

Communic. Serv. geol. Port., 56: 107-294; Lisboa.

KOKEN, E, (1884): Über Fisch-Otolithen, insbesondere

über diejenigen der nord-deutschen Oligozän-Ab-

lagerungen. – Z. deutsch. geol. Ges., 36: 500-565;

Berlin.

⎯ (1891): Neue Untersuchungen an tertiären Fischo-

tolithen, II. – Z. deutsch. geol. Ges., 43: 77-170; Berlin.

LANCKNEUS, J. & NOLF, D. (1979): Les otolithes des

téléostéens redoniens de Bretagne (Néogène de

l’Ouest de la France). – Bull. Inst. geol. Bassin Aqui-

taine, 25: 83-109.

LIEBUS, A. (1927): Neue Beiträge zur Kenntnis der

Eozänfauna des Krappfeldes in Kärnten. – Jahrb.

geol. Bundesanst., 77: 333-393; Wien.

MENZEL, H. (1986):Otolithen aus dem Oligozän und

Miozän von Nordwestdeutschland (zwischen Elbe-

Weser-Aller). In: Nordwestdeutschland im Tertiär.

– Beitr. Reg. Geol. Erde, 18: 446-502; Stuttgart.

MÜLLER, A. (1995, ms): Die Ichthyofauna des Obero-

ligozäns der Hessischen Senke (Raum Kassel, Bun-

desrepublik Deutschland). – Senckenberg Courri-

er, Frankfurt/M.

NOLF, D. (1972): Deuxième note sur les téléostéens des

sables de Lede (Éocène Belge). – Bull. Soc. belge.

Géol., Paléont., Hydrol., 81: 95-109; Bruxelles.

⎯ (1972): Sur la faune ichthyologique des formations

du Panisel et de den Horn (Éocène Belge). – Bull.

371

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Soc. belge Géol., Paléont., Hydrol., 81: 111-138; Brux-

elles.

⎯ (1972): Les otolithes du Calcaire Grossier à Fercourt

(Éocène du bassin de Paris). – Bull. Soc. belge Géol.,

Paléont., Hydrol., 81: 139-157.

⎯ (1976): Les otolithes des téléostéens de l’Oligo-Mi-

ocène belge. – Ann. Soc. roy. Zool. Belg., 106: 3-119;

Bruxelles.

⎯ (1976): Les otolithes des téléostéens néogènes de

Trinidad. – Eclogae Geol. Helv., 69: 703-742; Basel.

⎯ (1978): Les otolithes des téléostéens du Plio-Pleis-

tocène belge. – Geobios, 2: 517-559; Lyon.

⎯ (1981): Révision des types d’otolithes de poissons

fossiles décrits par R. Schubert. – Verh. Geol. B.-A.,

133-183; Wien.

⎯ (1985): Otolithi Piscium. – Handbook of Paleoich-

thyology, 10: 1-145; Gustav Fischer Verl., Stuttgart.

⎯ (1988): Les otolithes de téléostéens éocènes

d’Aquitaine et leur intérèt stratigraphique. – Acad.

roy. Belg., Mem. Cl. Sci., 19: 1-147.

NOLF, D. & BAJPAI, S. (1992): Marine Middle Eocene

fish otoliths from India and Java. – Bull. Inst. roy.

Sci. natur. Belg., 62: 195-221; Bruxelles.

NOLF, D. & CAPPETTA, H. (1976): Observations nou-

velles sur les otolithes des téléostéens du Calcaire

Grossier (Éocène du bassin de Paris). – Geobios, 9:

251-277; Lyon.

⎯ & ⎯ (1980): Les otolithes de téléostéens du Mi-

ocène de Montpeyroux (Hérault, France). – Palae-

overtebrata, 10: 1-28; Montpellier.

⎯ & ⎯ (1988): Otolithes de poissons pliocènes du

Sud-Est de la France. – Bull. Inst. roy. Sci. natur.

Belg., 58: 209-271; Bruxelles.

NOLF, D. & LAPIERRE, H. (1979): Otolithes de pois-

sons nouveaux ou peu connus du Calcier Grossier

et de la formation d’Auvers (Éocène du bassin paris-

ien). – Bull. Mus. natn. Hist. natur., 4: 79-125; Paris.

NOLF, D. & MARTINELL, J. (1980): Otolithes de

téléostéens du Pliocène des environs de Figueras

(Catalogne). – Geologica et Palaeontologica, 14: 209-

234; Marburg.

NOLF, D. & SMITH, R. (1983): Les otolithes de

téléostéens du stratotype des sables d’Edegem (Mi-

ocène inferieur de la Belgique). – Bull. Soc. belg.

Geol., 92: 89-98; Bruxelles.

NOLF, D. & STEURBAUT, E. (1983): Revision des oto-

lithes de téléostéens du Tortonien stratotypique et

de Montegibbio (Miocène superieur d’Italie sep-

tentrionale). – Meded. Werkgr. Tert. Kwart. Geol.,

20: 143-197; Leiden.

NOLF, D. & STRINGER, G. L. (1992): Neogene paleon-

tology in the northern Dominican Republic. 14:

Otoliths of teleostean fishes. – Bull. Amer. Paleont.,

102: 41-81; New York.

OHE, F. (1981): Fish-otoliths from the Dainichi sand

and the Fosoya tuffaceous members of the Pliocene

Kakegawa Group, Shizuoka Prefecture, Central

Japan. – Bull. Senior High School Aichi Univ. Educ.,

8: 125-194; Hirosawa.

372

Schwarzhans: Pleuronectiformes

⎯ (1983): On the otoliths of deep water fishes from

Pliocene Hijikata mud formation exposed in the

Southern part of Kakegawa City, Shizuoka Prefec-

ture, Central Japan. – Bull. Senior High School Ai-

chi Univ. Educ., 10: 1-54; Hirosawa.

POBEDINA, W. M. (1954): Iskopajenije otolity ryb mi-

ozenowyx otlozhenij Aserbajdzhana i ich strati-

graficheskoye znachenie. – Iswest. Akad. Aseba-

jdzhansk. SSSR, 23-37.

POSTHUMUS, O. (1929): Vischotolieten van NO-Bor-

neo. – Dienst. Mijnb. Nederland.-Indie Weten. Med-

ed., 9: 87-108; Bandung.

PRIEM, F. (1914): Sur des otolithes des poissons fossiles

des terrains tertiaires du Sud-Ouest de la France. –

Bull. Soc. geol. France, 14: 244-278; Paris.

RADWANSKA, U. (1984): Some new fish otoliths from

the Korytnica Clays (Middle Miocene; Holy Cross

Mountains, Central Poland). – Acta Geol. Polon.,

34: 299-322; Warszawa.

⎯ (1992): Fish otoliths in the Middle Miocene (Bade-

nian) deposits of southern Poland. – Acta Geol.

Polon., 42: 141-328; Warszawa.

REICHENBACHER, B. (1988): Die Fischfauna der Kirch-

berger Schichten (Unter-Miozän) an der Typusloka-

lität Illerkirchberg bei Ulm. – Stuttgarter Beitr.

Naturkde., 139: 1-53; Stuttgart.

SANZ ECHEVERRIA, J. (1950):Otolitos fosiles del ter-

ciario de Mallorca. – Inst. Invest. geol. “Lucas Malle-

da”, 435-451; Madrid.

SCHWARZHANS, W. (1973): Einige Otolithen aus dem

Unteroligozän von Hückelhoven unter besonderer

Berücksichtigung der Evolution der Trachinidae. –

Meded. Werkgr. Tert. Kwart. Geol., 10: 31-43; Lei-

den.

⎯ (1974): Die Otolithen-Fauna des Chatt A und B

(Oberoligozän, Tertiär) vom Niederrhein, unter Ein-

beziehung weiterer Fundstellen. – Decheniana, 126:

91-132; Bonn.

⎯ (1977): Otolithen aus dem Unteroligozän (Tertiär)

von Hückelhoven (Kreis Heinsberg, Nordrhein-

Westfalen). – Decheniana, 130: 268-292; Bonn.

⎯ (1978): Otolithen aus dem Unter-Pliozän von Süd-

Sizilien und aus der Toscana. – Berliner geowiss.

Abh. (A), 8: 1-52; Berlin.

⎯ (1980): Die tertiäre Teleosteer-Fauna Neuseelands,

rekonstruiert anhand von Otolithen. – Berliner ge-

owiss. Abh. (A), 26: 1-211; Berlin. – [1984: Fish oto-

liths from the New Zealand Tertiary (english trans-

lation). – Rep. N. Z. G. S., 113: 1-269; Lower Hutt]

⎯ (1981): Die Entwicklung der Familie Pterothrissi-

dae (Elopomorpha; Pisces), rekonstruiert nach Oto-

lithen. – Senckenbergiana lethaea, 62: 77-91; Frank-

furt/M.

⎯ (1985): Tertiäre Otolithen aus South-Australia und

Victoria (Australien). – Palaeo Ichthyologica, 3: 1-60;

München.

⎯ (1986): Die Otolithen des Unter-Pliozän von Le

Puget, S-Frankreich. – Senckenbergiana lethaea, 67:

219-273; Frankfurt/M.

⎯ (1994): Die Fisch-Otolithen aus dem Oberoligozän

der Niederrheinischen Bucht. Systematik, Palökol-

ogie, Paläobiogeographie, Biostratigraphie und

Otolithen-Zonierung. – Geol. Jahrb. (A), 140: 3-248;

Hannover.

⎯ (in prep.): Die Otolithen aus der Oberkreide

des Gerhartsreiter Grabens, Oberbayern. – Palaeo

Ichthyologica; München.

SCHUBERT, R. J. (1906): Die Fischotolithen des österre-

ichisch-ungarischen Tertiärs. – Jahrb. geol. Reich-

sanst., 56: 623-706; Wien.

SMIGIELSKA, T. (1973): Fish otoliths from the Lower

Tortonian deposits at Niskowa near Nowy Sacz. –

Roczn. P. T. Geol. (Ann. Soc. Geol. Pologne), 43:

1-40; Krakow.

STEURBAUT, E. (1979): Les otolithes de téléostéens des

Marnes de Saubriges (Miocène d’Aquitaine mérid-

ionale, France). – Palaeontographica (A), 166: 50-91;

Stuttgart.

⎯ (1984): Les otolithes de téléostéens de l’Oligo-Mio-

cène d’Aquitaine (Sud-Ouest de la France). – Pal-

aeontographica (A), 186: 1-162; Stuttgart.

STEURBAUT, E. & JONET, S. (1981): Révision des oto-

lithes de téléostéens du Miocène portugais. – Bull.

Soc. belge Géol., 90: 191-229; Bruxelles.

STINTON, F. (1966): Fish otoliths from the London

Clay. – Brit. Mus. natur. Hist., 404-478; London.

SUZIN, A. V. (1942): Otolity ryb miocenovykh otlosh-

enie Severnovo Kavkaza i Kerchenkovo. – Fond

AsNIN DN & Fond GrosNIN.

VORSTMANN, A. G. (1927): Tertiaire Vischotolieten van

Java. – Dienst. Mijnb. Nederland.-Indie Weten.

Meded.; 5: 1-16; Weltevreden.

WEILER, W. (1942): Die Otolithen des rheinischen und

nordwestdeutschen Tertiärs. – Abh. Reichsamt Bod-

enforsch., 206: 1-140; Berlin.

⎯ (1955): Untersuchungen an der Fischfauna von

Unter- und Ober-Kirchberg bei Ulm, vornehmlich

an Hand von Otolithen in situ. – Palaeontol. Z., 29:

88-102; Stuttgart.

⎯ (1958): Fisch-Otolithen aus dem Ober-Oligozän und

dem Mittel-Miozän der Niederrheinischen Bucht. –

Fortschr. Geol. Rheinland u. Westfalen, 1: 323-361;

Krefeld.

⎯ (1959): Miozäne Fisch-Otolithen aus der Bohrung

S. Pablo 2 im Becken von Veracruz in Mexiko. – N.

Jahrb. Geol. Palaeontol., 109: 147-172; Stuttgart.

⎯ (1962): Fisch-Otolithen aus dem oberen Mittelmio-

zän von Twistringen Bez. Bremen. – Geol. Jahrb.,

80: 277-294; Hannover.

WEINFURTER, E. (1952): Die Otolithen aus dem Tor-

ton (Miozän) von Mühldorf in Kärnten. – Sitz.-Ber.

österr. Akad. Wiss., math.-natur. Kl., 161: 149-172;

Wien.

⎯ (1952): Die Otolithen der Wetzelsdorfer Schichten

und des Florianer Tegels (Miozän, Steiermark). –

Sitz.-Ber. österr. Akad. Wiss., math.-natur. Kl., 161:

455-498; Wien.

373

Piscium Catalogus, Part Otolithi piscium, Vol. 2

Index

References to valid taxa and main discussion of valid taxa are in bold. References to taxa from

synonymy listings regarded as invalid are only presented from their individual entries – synony-

mized genera without type-species; synonymized species only under the species headings.

References to figures are in bold and denoted with an asterisk (*).

abbotti, Citharichthys 147

abbreviatus, Cynoglossus 342, 348, 349*

abentoni, Cynoglossus 347

abnormis, Aseraggodes 325

acadianus, Glyptocephalus 225

Acanthopsetta 210, 214, 218, 219, 220

nadeshnyi 219, 219*

Acedia 360

Achiroides 311

Achiropsetta 104, 208, 210

tricholepis 210

Achiropsis 269, 279, 280

nattereri 280

Achirus 8, 22, 35, 36, 269, 270, 271, 272, 276

achirus 272, 273, 273*, 276

barnharti 273

declivis 273, 274*

† fordycei 15, 337

garmani 273, 275, 275*, 276

klunzingeri 273

lineatus 273

lorentzi 273

mazatlanus 273, 274, 275*

novae 273

opercularis 273

scutum 273, 274, 275*

trichospilus 273

zebrinus 273

achirus, Achirus 272, 273, 273*, 276

Achlyopa 312

achne, Microstomus 246

acinaceus, Cynoglossus 352

aculeatus, Rhombus 91

acuminata, Plagusia 348

† acuminatus, (Pleuronectidarum) 15

acutirostris, Cynoglossus 342

Adamasoma 252

adspersus, Ammotretis 69

adspersus, Paralichthys 46*, 116, 117, 121, 121*

aegyptiaca, Solea 297, 298, 301*

Aesopia 269, 316

cornuta 316, 317, 317*

† granum 16, 317

aestuarius, Paralichthys 116

aethalion, Citharichthys 136

affinis, Pseudorhombus 131

Alaeops 265

albiguttata, Paralichthys 107, 116, 117, 118*, 119

albomaculata, Poecilopsetta 266*, 267

albomaculata, Synaptura 308*, 309

albomarginata, Poecilopsetta 267

algoensis, Paralichthodes 62, 64, 65, 65*

† alta, Paraplagusia 15, 356

altipinnis, Zebrias 321, 321*

† altus, Cynoglossus 15, 356

† altus, Rhinoplagusia 356

† altus, Rhombus 15, 17, 26

amaokai, Parabothus 162

Amate 332

amblybregmatus, Orthopsetta 149

americanus, Hippoglossus 213

americanus, Pseudopleuronectes 238, 239*

Ammopleurops 360

Ammotretis 27, 28, 29, 35, 40, 44, 45, 62, 65, 66, 68, 70

brevipinnis 69

elongatus 69, 69*

macrolepis 69

rostratus 68, 69, 69*

tudori 69, 69*

annadalei, Zebrias 321

Anathyridium 272

andersoni, Pseudorhombus 129

andriashevi, Mancopsetta 209

Ancylopsetta 38, 104, 106, 108, 115

antillarum 106, 108, 109*

cycloidea 106, 107, 108*

dendritica 107

dilecta 107, 108, 108*

kumperae 107

microtenus 107, 108, 108*

quadrocellata 106, 107, 107*

andrewsi, Arnoglossus 168

† angulata, Solea 15, 17

angulosa, Solea 295

† angulosus, Lepidorhombus 15, 20, 24, 95, 96, 97, 98*, 99

angustirostris, Limanda 238

† angustus, Citharopsettodes 15, 77

† angustus, Paracitharus 11, 15, 20, 25, 77, 78, 79*,

Anisochirus 269, 310, 314, 316

panoides 312, 314, 316*

annamensis, Pseudorhombus 132

annectens, Coccolus 159

annectens, Pseudaustroglossus 306

annularis, Brachirus 312

annulatus, Pseudorhombus 125, 130, 130*, 133

anomalus, Pseudorhombus 131

antarctica, Mancopsetta 209

Anticitharus 166

antillarum, Ancylopsetta 106, 108, 109*

antillarum, Monolene 197, 198*

† antiqua, Solea 286

†aomoriensis, Limanda 15, 17

374

Schwarzhans: Pleuronectiformes

Aphorista 360

Apionichthys 35, 52, 269, 279

dumerili 280, 280*

apoda, Pleuronectes 271

† approximata, Solea 15, 23, 24, 285, 286, 288, 290

† approximatum, Buglossidium 285, 288

Apsetta 252

Apterygopectus 208

aquosus, Scophthalmus 91, 92, 93*

arabicus, Arnoglossus 168

arabicus, Symphurus 362

Araias 228

aramaca, Pleuronectes 137

aramaca, Rhombus 119

Aramaca 135

arawak, Symphurus 362

arctifrons, Orthopsetta 149, 151, 152*

arel, Cynoglossus 342, 351, 351*, 352, 353

Arelia 340

Areliscus 340

arenaceus, Citharichthys 147

arenicola, Engyprosopon 202

argus, Pleuronectes 159, 160

argus, Pseudorhombus 125, 132*, 133

ariommus, Araias 230

armstrongi, Arnoglossus 168

† arnoglossoides, Caulopsetta 15, 21, 27, 183, 184*

arnoglossus, Pleuronectes 168

Arnoglossus 11, 12, 24, 45, 51, 52, 104, 105, 165, 166, 182, 183,

184, 186, 193

andrewsi 168

arabicus 168

armstrongi 168

aspilos 168, 176*, 177

bassensis 168

† bauzai 15, 25, 172

capensis 167, 168, 171*, 175, 183

dalgleishi 167, 168, 181, 182*

debilis 168, 181, 181*

elongatus 168

† extremus

15, 20, 27, 168, 178, 178*

fisoni 168

† grenfelli 16, 20, 27, 168, 180, 180*

grohmanni 168, 170, 171*

† holleri 16, 20, 24, 25, 168, 170, 172, 173*, 286

imperialis 18, 20, 24, 167, 168, 169, 170, 171*

† inconspectus 16, 172

japonicus 168

† kokeni 15, 16, 18, 20, 25, 26, 168, 170, 172, 174*, 175

kotthausi 168

† lapierrei 16, 20, 23, 168, 177, 177*, 178

laterna 14, 18, 20, 24, 27, 122, 166, 167, 168, 168*, 169,

170, 172, 174, 175, 181

† longus 16, 20, 27, 52, 167, 168, 178, 179*, 184

macrostoma 168, 169, 169*

maculipinnis 168

marisrubri 168

† miocenicus 16, 170, 172

muelleri 168

multirastris 168

† novus 16, 20, 27, 52, 167, 168, 179, 180*, 184

oxyrhynchus 168

polyspilus 168

† prudhommae 16, 20, 24, 168, 177*, 178

† quadratus 16, 21, 26, 167, 168, 170, 174, 175*

rueppelli 10, 167, 168, 176, 176*, 177

sayaensis 168

tapeinosoma 167, 168, 176, 176*, 177

† taureri 16, 17, 18, 21, 24, 25, 168, 170, 172, 173*

tenuis 168

thori 168, 169, 171*

waitei 168, 176*, 177

arsius, Pseudorhombus 124, 125, 127, 129, 129*, 134

asaedae, Monolene 197

asanoi, Samariscus 261

Aseraggodes 8, 269, 323, 324, 326

abnormis 325

bahamondi 325

beauforti 325

cyaneus 325, 326, 326*

dubius 325

filiger 325, 326, 327*

guttulatus 324, 325

haackeanus 325

herrei 325

kaianus 325

klunzingeri 325, 326, 327*

kobensis 325, 325*, 326

macleayanus 325, 326, 327*

melanostictus 325

microlepidotus 325

normani 325

ocellatus 325

persimilis 325

sinusarabici 325

smithi 325

texturatus 325

whitakeri 325

aspera, Limanda 227, 228, 229*

asperrimum, Clidoderma 18, 21, 27, 245, 245*

aspilos, Arnoglossus 168, 176*, 177

aspilos, Heterobuglossus 310, 311*

asphyxiatus, Pnictes 280

asprella, Limanda 228

assimilis, Bothus 158

Asterorhombus 104, 166, 168, 199, 200

fijiensis 200, 201

intermedius 166, 200, 201, 201*

Atherestes 210, 214, 215, 223

evermanni 215, 216*

stomias 19, 21, 215, 216*

atlanticus, Bothus 159

atlanticus, Citharichthys 154

atlanticus, Monochirus 290

atramentatus, Symphurus 362, 365, 366*

atricaudus, Symphurus 18, 22, 52, 361, 362, 364, 364*

atrimana, Monolene 197

attenuatus, Cynoglossus 341, 342

aurantiaca, Solea 300

aureus, Citharichthys 159

aurolimbata, Plagusia 356

australis, Microchirus 283

australis, Rhinoplagusia 349

australis, Symphurus 362

austrinus, Achirus 271

Austroglossus 269, 297, 306

375

Piscium Catalogus, Part Otolithi piscium, Vol. 2

microlepis 306, 307

pectoralis 306, 307, 307*

avilesi, Apterygopectus 209

† awamoaensis, Grammatobothus 15, 20, 27, 163, 164, 165*

axillaris, Brachypleurops 79

ayresii, Parophrys 250

Azevia 141

azevia, Solea 293

Azygopus 34, 35, 40, 65, 210, 211, 254, 263

pinnifasciatus 263, 264, 264*

bahamondi, Aseraggodes 325

bahianus, Rhombus 159

Baiostoma 272

† balangoensis, Solea 15, 17

† balearicus, Citharus 15, 18, 20, 25, 26, 72, 75, 75*, 76

balteata, Platessa 129

baltica, Pluronectes 235

barbatus, Rhombus 91

Barbourichthys 311

barnardi, Coryphaesopia 317

Barnardichthys 296

barnharti, Achirus 273

† bartonensis, Solea 15

Bascanius 166, 360

bassensis, Arnoglossus 168

bassensis, Rhombosolea 69

† bassolii, Phrynorhombus 15, 102

bathybius, Embassichthys 246

Bathysolea 10, 35, 269, 280, 281, 302, 304

lactea 305, 306

† polonica 16, 21, 25, 305*, 306

profundicola 305, 305*, 306

† bauzai, Arnoglossus 15, 25, 172

† bavayi, Psettodes 15, 19, 23, 58, 61, 62*, 64

beani, Poecilopsetta 266*, 267

Beaufortella 324

beauforti, Aseraggodes 325

belcheri, Psettodes 58, 59*

† belgicus, Citharus 83

†

belgicus, Eucitharus 15, 82

bellonaensis, Engyprosopon 202

bengalensis, Plagusia 358

bennettii, Psettodes 58

bergi, Symphurus 362

† biaculeatus, (Bothidarum) 15

† biaculeatus, Rhombocitharus 15, 20, 23, 81

Bibronia 360

bicolorata, Marleyella 55, 264, 265*

bicoloratus, Kareius 236, 239*

bicyclophorus, Paralichthys 116

bilineata, Lepidopsetta 240, 240*, 241

bilineata, Paraplagusia 18

bilineatus, Achirus 344

bilineatus, Cynoglossus 18, 22, 27, 342, 344, 348, 350*, 351

blachei, Arnoglossus 170

bleekeri, Apionichthys 280

bleekeri, Bothus 158

bleekeri, Engyprosopon 202, 203, 203*

bleekeri, Solea 297, 298

blochi, Cynoglossus 342, 350*, 351

† boerialensis, Pleuronectes 15

bogdanovi, Pleuronectes 236

bollmani, Hippoglossina 110

boops, Caulopsetta 183

Boopsetta 265

borbonica, Solea 318

borealis, Pleuronectes 235

borneensis, Cynoglossus 342, 344, 345*

borneensis, Engyprosopon 202

boscanion, Microchirus 281, 282, 283, 284*

boscii, Lepidorhombus 10, 18, 94, 95, 95*

(Bothidarum)

† biaculeatus 15, 16

† dorsolobatus 15

† heletroides 16

† lapierrei 16, 177

† obliquus 16

† rhomboides 17

† weileri 17

Bothus 8, 11, 24, 44, 45, 51, 56, 104,

157, 162, 200

assimilis 158

bleekeri 158

constellatus 158, 159, 160*

† contortus 15, 17

† decipiens 15, 17

ellipticus 158

guibei 158

leopardinus 158, 160

lunatus 158, 160, 160*

mancus 158, 161, 161*

melissi 158

myriaster 158, 161, 161*

ocellatus 158, 159, 160*

ovalis 158, 161

pantherinus 158, 159, 159*, 160

podas 157, 158, 159, 159*, 160

robinsi 158

† rosenthalensis 17

† semen 17

tricirrhatus 158

ypsigrammus 158

Bowenia 252

Brachirus 8, 35, 36, 269, 310, 311, 314, 323

annularis 312

breviceps 312

cinerascens 312, 314, 315*

melanorhynchus 312, 314, 315*

niger 312, 313, 313*

orientalis 311, 312, 313*, 314

pan 312, 314, 315*

salinarum 312

selheimi 312

villosa 312

zanzibarica 312

brachycephalus, Cynoglossus 353

Brachypleura 12, 34, 37, 38, 42, 44, 64, 71, 84, 85, 86, 210

novaezeelandiae 86, 87, 87*

, 226

† pentagonalis 16, 20, 24, 86, 87, 88, 88*

† xenosulcis 17, 20, 26, 86, 87, 88, 89*

Brachypleurops 79

Brachyprosopon 246

brachyrhynchus, Plagusia 356

brasiliensis, Paralichthys 116, 119, 119*, 121

376

Schwarzhans: Pleuronectiformes

brasiliensis, Xystreurys 112

breviceps, Brachirus 312

brevipinnis, Ammotretis 69

brevirictis, Psettina 186, 187*

brevirostris, Cynoglossus 358

brevirostris, Plagusia 348

brevis, Cynoglossus 356

broadhursti, Cynoglossus 342, 355, 357*

browni, Cynoglossus 342

browni, Solea 271

brunneus, Cynoglossus 352

buchanani, Cynoglossus 358

Buglossidium 281, 282

† approximatum 285, 288

† frequens 15, 285, 286, 288

luteum 19, 281

Buglossus 281

cacatuae, Arnoglossus 259

cadenati,Cynoglossus 342

cadenati, Synaptura 308

caeca, Cryptops 323

caeruleosticta, Paralichthys 116

californicus, Paralichthys 18, 20, 114, 115, 116, 120, 120*,

121, 122

calimanda, Pleuronectes 103

callopterus, Symphurus 362

canariensis, Cynoglossus 342, 343, 343*, 344

cancellatus, Zebrias 321, 322, 322*

candidissimus, Rhombus 159

cantori, Trulla 344

Cantoria 340

cantoris, Plagusia 351

capellonis, Solea 301

capensis, Arnoglossus 167, 168, 171*, 175, 183

capensis, Cynoglossus 342

capensis, Heteromycteris 332, 333*

caribbaea, Trichopsetta 190

caribbeanus, Symphurus 362

carnaria, Platessa 236

carpentari, Cynoglossus 342, 359, 361*

cartwrighti, Pseudorhombus 129

Catathyridium 269, 270, 273, 275

grandiviri 276

jenynsi

275, 276, 276*

Caulopsetta 104, 165, 168, 176, 182

† arnoglossoides 15, 21, 27, 183, 184*

boops 183

scapha 182, 183, 183*, 184

† cauneillensis, Citharus 15, 83

† cauneillensis, Rhombocitharus 15, 20, 23, 81, 83, 83*

cayennensis, Citharichthys 147

Cephalopsetta 38, 104, 124, 135

ventrocellatus 135

ceratophrys, Arelia 358

Chabanaudetta 314

chabanaudi, Symphurus 362*, 363

Chaenopsetta 114, 115

chartes, Platotichthys 160

Charybdia 166

Chascanopsetta 10, 34, 44, 45, 48, 49, 104, 105, 206, 207, 208

galathaea 207

lugubris 19, 27, 46*, 135, 207, 207*

megagnatha 207

micrognathus 207

microstoma 207

prognathus 207

prorigera 207

cheni, Heteromycteris 332

chirophthalma, Vanstraelenia 303, 304, 304*

chittendeni, Cyclopsetta 141, 142*, 143

chlorospilus, Parabothus 162, 162*

Chopinopsetta 71

chui, Nematops 269

cicatricosus, Pleuronectes 231

ciliaris, Engyophrys 191

cinerascens, Brachirus 312, 314, 315*

cinnamoneus, Pseudorhombus 125, 126, 126*

† circularis, Eucitharus 15

circularis, Platophrys 161

† circularis, Rhombocitharus 15, 20, 23, 81, 83

Citharichthys 11, 34, 38, 42, 44, 52, 104, 145, 148, 149, 154, 156

abbotti 147

arenaceus 147

gilberti 147, 147*

macrops 147, 148, 148*

platophrys 147

sordidus 19

spilopterus 145, 146*, 147

stampfli 146*, 147

stigmaeus 19

uhleri 147

† varians 17

xanthostigma 19

Citharoides 11, 37, 70, 71, 72, 79

macrolepidotus 79, 80*

† Citharopsettodes 13, 70, 77

† angustus 15, 77

Citharus 11, 70, 71, 72, 77

† balearicus 15, 18, 19, 25, 26, 72, 75, 75*, 76

† cauneillensis 15

† latisulcatus 16

linguatula 18, 71, 72, 73*, 74, 75, 82

† lusitanicus 16, 17, 19, 24, 25, 72, 74*, 75

† miocenicus 75, 76

† schuberti 17, 19, 25, 72, 76, 76*

sp. 74*, 75

civitatus, Symphurus 362, 364, 364*

† claibornensis, Eosolea 15

clarus, Laeops 193

Cleisthenes 210, 214, 216

herzensteini 217, 217*

pimetorum 217

clerveleyi, Solea 295

Clidoderma 210, 243, 244, 245

asperrimum 18, 21, 27, 245, 245*

coarctus, Parabothus 162

Coccolus 157

cochinensis, Zebrias

321

cocosensis, Engyprosopon 202*, 203

coenosus, Pleuronichthys 246, 247, 248*

Colistium 62, 65, 66, 68

guentheri 66, 67, 67*, 68

nudipinnis 66, 67, 67*, 68

377

Piscium Catalogus, Part Otolithi piscium, Vol. 2

† collatus, Psettodes 15, 16, 17, 19, 23, 58, 60*, 61*

colorata, Poecilopsetta 265, 267

comifer, Achirus 271

commersoniana, Synaptura 18, 308, 308*

† concaviventris, Etropus 15, 20, 22, 156, 156*

† concavus, (Pleuronectidarum) 15

conspersus, Pleuronectes 168

constellatus, Bothus 158, 159, 160*

† contortus, Bothus 15, 17

cooperi, Metoponops 149

corallinus, Samariscus 261

coreanicus, Paralichthys 122

† corius, Rhombus 15, 17

cornuta, Aesopia 316, 317, 317*

† cornuta, Quenselia 15, 21, 25, 26, 44, 291, 292, 293, 293*, 295

cornutus, Orthopsetta 149, 152, 153*

cornutus, Pleuronichthys 18, 21, 27, 247

† corpulentus, Solea 15

Coryphaesopia 316

Coryphyllus 324, 326

costae, Samaris 259

† cottreaui, Solea 15

craticulus, Zebrias 321

cristatus, Lophorhombus 185

cristatus, Pleuronectes 91

cristatus, Samaris 258, 259, 260*

crossolepis, Pseudaesopia 320

Crossolepis 186

Crossorhombus 104, 157, 158, 199, 201, 204

azureus 204, 205*

howensis 204

kanekonis 204, 205*

valderostratus 204, 205*

crossotus, Etropus 152, 153, 154, 154*

crumenalis, Pelecanichthys 208

Cryptops 323

ctenosquamis, Spinirhombus 126

cuneata, Dicologlossa 18, 47*, 133, 286, 287, 294, 295, 297

Curioptera 69

cyaneus, Aseraggodes

325, 326, 326*

cycloidea, Ancylopsetta 106, 107, 108*

cyclops, Pleuronectes 91

Cyclopsetta 38, 48, 104, 109, 135, 136, 141, 145

chittendeni 141, 142*, 143

fimbriata 141, 143, 143*

maculifera 141

panamensis 19, 20, 22, 141, 143, 144*

querna 109, 141, 142*, 143

† transitus 17, 20, 22, 143, 145*

cyclosquamus, Etropus 153

Cynicoglossus 246

Cynoglossoides [VON BONDE 1922] 340

Cynoglossoides [SMITH 1949] 340

cynoglossus, Cynoglossus 342, 358, 359*

Cynoglossus 36, 40, 52, 338, 339, 340, 341, 342, 359, 361

abbreviatus 342, 348, 349*

acutirostris 342

† altus 15, 356

arel 342, 351, 351*, 352, 353

attenuatus 341, 342

bilineatus 18, 22, 27, 342, 344, 348, 350*, 351

blochi 342, 350*, 351

borneensis 342, 344, 345*

broadhursti 342, 355, 357*

browni 342

cadenati 342

canariensis 342, 343, 343*, 344

capensis 342

carpentari 342, 359, 361*

cynoglossus 342, 358, 359*

dispar 341, 342, 348, 350*

dollfusi 342

dubius 342, 344, 345*

durbanensis 342

ecaudatus 341, 342

feldmanni 342, 347, 347*

gilchristi 342, 356, 357*, 358

gracilis 342, 347, 348, 349*

heterolepis 342, 346, 347*

interruptus 342, 354, 354*

itinus 342, 353, 354*

japonicus 18, 22, 27, 342, 348, 350*, 351

joyneri 18, 22, 27, 342, 353, 353*

kapuasensis 342, 346, 347*

kopsi 342, 353, 354*

lachneri 342

† leuchsi 15, 16, 17, 22, 24, 25, 342, 356, 358*

lida 341, 342, 346, 346*

lingua 340, 342, 351, 352, 352*

macrophthalmus 342

macrostomus 342

maculipinnis 342, 356, 357*

marleyi 342, 359

microlepis 342

microphthalmus 342

monodi 342

monopus 342, 358, 359*

† obliqueventralis 16, 22, 26, 342, 343, 343*

ogilbyi 342

puncticeps 342, 356, 357*, 358

quadrilineatus 342, 344, 346*

robustus 342, 351, 352, 352*, 353

sealarki 341, 342, 355, 355*

semifasciatus 342, 358, 359*

semilaevis 342, 347, 348, 349*

senegalensis 342, 344, 345*

sinusarabici 342

suyeni 342

trigrammus 342, 348, 349*

unicolor

342, 350*, 351

wandersi 342

zanzibarensis 342, 355, 355*

cynoglossus, Glyptocephalus 225, 226*

cynoglossus, Pleuronectes 223

Cynopsetta 219

cypho, Laeops 193

Dageichthys 269, 280, 301

lakdoensis 301

dalgleishi, Arnoglossus 167, 168, 181, 182*

danae, Monolene 197

darwini, Oncopterus 69, 70, 70*

debilis, Arnoglossus 168, 181, 181*

† decipiens, Bothus 15, 17

378

Schwarzhans: Pleuronectiformes

declivis, Achirus 273, 274*

decurrens, Pleuronichthys 247, 248, 248*

delagoensis, Samaris 259

Delothyris 197

delsmani, Etropus 153

deltae, Cynoglossus 358

dendritica, Ancylopsetta 107

dentatus, Hippoglossoides 220

dentatus, Japanolaeops 196

dentatus, Paralichthys 116, 117, 117*, 121

dentex, Hippoglossus 58

derentensis, Taratretis 70

desoutterae, Samariscus 261

Dexillichthys 269, 310

macrolepis 311, 312*

muelleri 311

setiger 311

Dexillus 310

Dexiourius 340, 342

Dexistes 210, 223, 226, 228

rikuzenius 228, 230, 230*

diabolicus, Symphurus 362

diagrammus, Pleuronectes 232

diaphanus, Bothus 159

diaphanus, Pleuronectes 168

Dicologlossa 48, 49, 269, 280, 281, 282, 291, 294

cuneata 18, 47*, 133, 286, 287, 294, 295, 297

hexophthalma 18, 291, 294, 295, 295*, 296

† patens 16, 18, 19, 21, 24, 25, 294, 296, 297*

dignabilis, Pseudopleuronectes 238

dilecta, Ancylopsetta 107, 108, 108*

dimorphus, Platophrys 204

dinoceros, Orthopsetta 149

diomedianus, Symphurus 362

diplasios, Arelia 344

diplospilus, Pseudorhombus 125

dipterygia, Plagusia 348

dispar, Cynoglossus 341, 342, 348, 350*

diurus, Scophthalmus 235

Dollfusetta 166

dollfusi, Cynoglossus 342

Dollfusiana 166

Dollfusichthys 340

† dominicensis, Syacium 15, 20, 22, 136, 139, 140*

† dorsolobata, Taeniopsetta 15, 21, 188, 189*

† dorsolobatus, (Bothidarum) 15

Dorsopsetta 109

norma 109, 143

Drepanopsetta 219

dubiosa, Monolene 197

dubius, Aseraggodes 325

dubius, Cynoglossus 342, 344, 345*

dubius, Hippoglossoides 220, 222*, 223

dumerili, Apionichthys 280, 280*

dupliciocellatus, Pseudorhombus 125, 129, 130*

durbanensis, Cynoglossus 342

dwinensis, Platessa 231

ecaudatus, Cynoglossus 341, 342

Echinosolea 290

ectenes, Etropus 153

elassodon, Hippoglossoides 220, 221*

elegans, Tarphops 135

elevatus, Pseudorhombus 125, 131, 131*

ellipticus, Bothus 158

elongata, Platessa 225

elongatus, Ammotretis 69, 69*

elongatus, Arnoglossus 168

elongatus, Cynoglossus 351

elongatus, Microbuglossus 302, 303*

† elongatus, Pleuronectes 15, 18

elongatus, Symphurus 362*, 363

elongatus, Xenobuglossus 295

Embassichthys 210, 245, 246

bathybius 246

Engyophrys 38, 104, 105, 189, 190, 191, 192

ciliaris 191

sanctilaurenti 190, 191, 192*

sentus 191

Engyprosopon 8, 51, 56, 104, 157, 158, 199, 201, 204

arenicola 202

bellonaensis 202

bleekeri 202,

203, 203*

borneensis 202

cocosensis 202*, 203

filimanus 202, 202*, 203

grandisquama 202, 203, 203*

hawaiensis 202

hensleyi 202

hureaui 202

latifrons 202

longipelvis 202

longipterum 202

macrolepis 202

macroptera 202

maldivensis 202

mogkii 201

multisquamata 202

natalensis 202

raoulensis 202

regani 202

rostratum 202

sechellensis 202

septempes 202

smithi 202

ui 19, 135

xenandrus 201, 202, 202*

entomorhynchus, Arnoglossus 175

Eopsetta 48, 49, 210, 212, 227, 232

grigorjewi 212

jordani 18, 21, 212, 213, 213*

† Eosolea 13

† claibornensis 15

† texana 17

Errex 225

erumei, Psettodes 57, 58, 59*

Etropus 38, 104, 145, 149, 152

† concaviventris 15, 20, 22, 156, 156*

crossotus 152, 153, 154, 154*

cyclosquamus 153

delsmani 153

ectenes 153

intermedius 153, 154, 154*

longimanus 153, 154, 155, 155*

379

Piscium Catalogus, Part Otolithi piscium, Vol. 2

microstomus 153, 155, 155*

peruvianus 153

rimosus 153

Euchalarodus 230

Eucitharus 71

† belgicus 15

† circularis 15

† lusitanicus 16

† miocenicus 16, 18, 24

† schuberti 17

Eupnoea 360

Euporista 360

Euryglossa 311

Eurypleura 311

evermanni, Atherestes 215, 216*

excisiceps, Teratorhombus 129

exilis, Lyopsetta 18, 21, 27

† extremus, Arnoglossus 15, 20, 27, 168, 178, 178*

fallax, Symphurus 362

† fangariensis, (Pleuronectidarum) 15, 18

fasciata, Plagusia 363

fasciatus, Achirus 271

fasciatus, Nodogymnus 278

fasciatus, Pleuronectes 283

fasciatus, Samariscus 261

fasciatus, Zebrias 321

fasciolaris, Symphurus 362

feldmanni, Cynoglossus 342, 347, 347*

fernandezianus, Paralichthys 116

ferruginea, Limanda 18, 227, 228, 229*

filiger, Aseraggodes 325, 326, 327*

filimanus, Engyprosopon 202, 202*, 203

filipectoralis, Samariscus 261

fimbriata, Cyclopsetta 141, 143, 143*

fimbriatus, Trinectes 271

finis, Soleonasus 280

fischeri, Solea 271

fisoni, Arnoglossus 168

flavilatus, Pelotretis 251, 252, 253*

flesoides, Pleuronectes 235

flesoides, Rhombosolea 254

flesus, Platichthys

18, 21, 24, 53, 55*, 235, 237*

† flexodorsalis, Peltorhamphus 15, 22, 27, 334, 335, 337*

fluviatilis, Trinectes 271

foliacea, Solea 312

† foliformis, Rhombus 15, 18

fonsecensis, Trinectes 271, 272, 272*

† fordycei, Achirus 15, 337

† fordycei, Peltorhamphus 15, 22, 27, 334, 337, 338*

formoana, Rhinoplagusia 349

formosanus, Pseudorhombus 126

fragilis, Orthopsetta 149, 150*, 151

frechkopi, Microchirus 282, 292

† frequens, Buglossidium 15, 285, 286, 288

† frequens, Microchirus 14, 15, 21, 23, 24, 25, 51, 283, 285,

285*, 290

frontalis, Gastropsetta 108, 109, 109*

fulvomarginata, Solea 298

fuscus, Hemirhombus 147

fuscus, Symphurus 362

galathaea, Chascanopsetta 207

gallus, Lophonectes 185, 185*

garmani, Achirus 273, 275, 275*, 276

Gastropsetta 38, 104, 105, 106, 108

frontalis 108, 109, 109*

gesneri, Rhombus 159

gigantea, Psettina 186

gigas, Hippoglossus 213

gilberti, Citharichthys 147, 147*

gilchristi, Chascanopsetta 207

gilchristi, Cynoglossus 342, 356, 357*, 358

gilesi, Symphurus 360, 362, 366*, 367

gilli, Pleuronectes 246

ginsburgi, Symphurus 362

† glaber, Solea 16

glabra, Platessa 231, 236

glacialis, Liopsetta 230, 231, 231*

glossa, Plagiopsetta

257, 258, 258*

Glossichthys 360

Glyptocephalus 10, 11, 44, 45, 48, 49, 210, 223, 225

cynoglossus 225, 226*

stelleri 225

zachirus 19, 21, 47*, 225, 226*, 227*

goniographicus, Hippoglossus 58

goreensis, Cynoglossus 344

gorgonae, Symphurus 362

gracilis, Cynoglossus 342, 347, 348, 349*

gracilis, Laeops 193

Grammatobothus 104, 157, 158, 162

† awamoaensis 15, 20, 27, 163, 164, 165*

krempfi 163

pennatus 163

polyophthalmus 162, 163, 163*, 164

† radwanskae 16, 20, 25, 163, 164*

Grammichthys 272

grandisquama, Engyprosopon 202, 203, 203*

grandisquama, Nematops 269, 269*

grandisquamis, Plagusia 351

grandiviri, Catathyridium 273, 276

† Granulithus 13, 269, 316, 317

† granum 16, 21, 23, 317, 318*

† granum, Aesopia 16, 317

† granum, Granulithus 16, 21, 23, 317, 318*

† grenfelli, Arnoglossus 16, 20, 27, 168, 180, 180*

grigorjewi, Eopsetta 212

groenlandicus, Microstomus 246

grohmanni, Arnoglossus 168, 170, 171*

gronovii, Solea 273

guatimalensis, Citharichthys 147

guentheri, Colistium 66, 67, 67*, 68

guentheri, Laeops 193, 193*

† guestfalica, Solea 16, 82

guibei, Bothus 158

guineensis, Hemirhombus 136

gunteri, Syacium

136, 138, 139*

guttata, Plagusia 348

guttulata, Hypsopsetta 249, 250, 251*

guttulatus, Aseraggodes 324, 325

Gymnachirus 35, 269, 270, 277

melas 278, 279*

380

Schwarzhans: Pleuronectiformes

nudus 277

gymnorhinus, Orthopsetta 149

haackeanus, Aseraggodes 325

hamiltoni, Cynoglossus 358

Haplozebrias 320

hardenbergi, Cynoglossus 347

harmandi, Solea 314

hartzfeldi, Rendahlia 332, 334, 335*

hawaiensis, Engyprosopon 202

hawaiiensis, Poecilopsetta 267

heckelii, Peloria 159

hectoris, Pseudorhombus 183

hedleyi, Pardachirus 329, 330, 331*

heini, Microbuglossus 302, 303*

† heletroides, (Bothidarum) 16

† helvecianus, Pseudorhombus 16

Hemirhombus 135

hensleyi, Engyprosopon 202

herrei, Aseraggodes 325

herzensteini, Cleisthenes 217, 217*

herzensteini, Pseudopleuronectes 238, 239*

Heterobuglossus 269, 310

aspilos 310, 311*

heterolepis, Cynoglossus 342, 346, 347*

heterolepis, Synaptura 310

Heteromycteris 18, 36, 45, 269, 330, 332, 334

capensis 332, 333*

cheni 332

japonicus 332, 333*

matsubarai 332

oculus 332, 333*

proboscideus 332

heterophthalmus, Rhombus 159

Heteroprosopon 246

heterorhinos, Soleichthys 318, 319*

hexophthalma, Dicologlossa 18, 291, 294, 295, 295*, 296

hexophthalmus, Microchirus 282

hilgendorfi, Paralichthys 116

Hippoglossina 38, 53, 104, 106, 109, 112, 113

bollmani 110

macrops 109, 110, 110*

montemaris 110

mystacium 110

stomata

110, 111, 111*

Hippoglossoides 44, 45, 48, 49, 210, 214, 218, 219, 223, 241

dubius 220, 222*, 223

elassodon 220, 221*

platessoides 19, 21, 24, 220, 221*

robustus 220

hippoglossoides, Reinhardtius 47*, 221, 223, 224*

Hippoglossus 10, 11, 52, 210, 212, 213

hippoglossus 213, 214*

stenolepis 19, 21, 213, 214, 214*

hippoglossus, Hippoglossus 213, 214*

hirtus, Pleuronectes 101

hispidus, Monochirus 290, 291*

hollandi, Areliscus 348

† holleri, Arnoglossus 16, 20, 24, 25, 168, 170, 172, 173*, 286

Holonodus 320

holothuriae, Symphurus 362

hubbardi, Parophrys 232

humilis, Solea 302

† hunyadensis, (Pleuronectidarum) 16, 18

hureaui, Engyprosopon 202

huysmani, Samariscus 261, 262, 263*

Hypoclinemus 269, 270, 276

mentalis 277, 277*

paraguayensis 276, 277

Hypsopsetta 48, 49, 210, 245, 246, 247, 249

guttulata 249, 250, 251*

Icania 340, 342

† ignobilis, Limanda 16, 21, 23, 227, 228, 229*

iijimae, Psettina 186*, 187

immaculatus, Cynoglossus 356

impar, Solea 298

imperialis, Arnoglossus 18, 20, 24, 167, 168, 169, 170, 171*

† inconspectus, Arnoglossus 16, 172

indica, Solea 273

inermis, Platophrys 162

inermis, Poecilopsetta 267

Inopsetta 210, 226,

240

ishyra 240, 241, 241*

inornatus, Samariscus 261

inscriptus, Trinectes 271

insignis, Vanstraelenia 303, 304, 304*

intermedius, Asterorhombus 166

intermedius, Cynoglossus 346

intermedius, Etropus 153, 154, 154*

intermedius, Hippoglossus 137

interruptus, Cynoglossus 342, 354, 354*

inusita, Cynoglossus 352

† irregularis, (Pleuronectidarum) 16, 18, 22

ishyra, Inopsetta 240, 241, 241*

isocles, Paralichthys 115, 116, 122, 123*, 125

isolepis, Isopsetta 18, 21, 242, 243, 243*

Isopsetta 44, 210, 233, 241, 242

isolepis 18, 21, 242, 243, 243*

Istiorhombus 124

italicus, Pleuronectes 236

itinus, Cynoglossus 342, 353, 354*

Japanolaeops 196

dentatus 196

japonica, Paraplagusia 18

japonica, Pseudaesopia 320, 320*

japonicus, Arnoglossus 168

japonicus, Cynoglossus 18, 22, 27, 342, 348, 350*, 351

japonicus, Heteromycteris 332, 333*

japonicus, Samariscus 261, 262*

Japonolaeops 104, 189

jaubertensis, Rendahlia 332, 333, 334, 335*

javanica, Plagusia 356

javanicus, Pseudorhombus 125, 127, 128*, 129

jenynsi, Catathyridium 275, 276, 276*

jenynsi, Symphurus 362

jenynsii, Pseudorhombus 125, 131, 131*, 132

† Joleaudichthys 57

jordani, Eopsetta 18, 21, 212, 213, 213*

381

Piscium Catalogus, Part Otolithi piscium, Vol. 2

jordani, Paralichthys 121

joyneri, Cynoglossus 18, 22, 27, 342, 353, 353*

kaianus, Aseraggodes 325

Kamoharaia 104, 207, 208

megastoma 208

kapuasensis, Cynoglossus 342, 346, 347*

† karaganensis, Rhombus 16

Kareius 210, 226, 235, 236

bicoloratus 236, 239*

katakurae, Hippoglossoides 220

kaupii, Arelia 351

keralensis, Zebrias 321

kessleri, Arnoglossus 170

kiensis, Parabothus 162

kingii, Hippoglossus 121

† kirchbergeana, Solea 16, 286

† kirchbergeanus, Microchirus 14, 16, 17, 18, 21, 24, 25, 51,

283, 286, 287*

kitaharae, Laeops 193

kitaharae, Tanakius 223, 224, 225*

kitt, Microstomus 246, 247*

kleini, Solea 298, 301, 301*

† klockenhoffi, Lepidorhombus 16, 20, 24, 95, 99, 99*, 100

klunzingeri, Achirus 273

klunzingeri, Aseraggodes 325, 326, 327*

kobensis, Aseraggodes 325, 325*, 326

kobensis, Scaeops 204

krempfi, Grammatobothus 163

† kokeni, Arnoglossus 15, 16, 18, 20, 25, 26, 168, 170, 172,

174*, 175

† kokeni [BASSOLI 1906], Solea 16, 172, 296

† kokeni [SCHUBERT 1906], Solea 16, 296

† konkensis, Rhombus 16, 18

kopsi, Cynoglossus 342, 353, 354*

kotthausi, Arnoglossus 168

kumperae, Ancylopsetta 107

kyaropterygium, Symphurus 362

Kyleia

166

lachneri, Cynoglossus 342

lactea, Bathysolea 305, 306

lactea, Plagusia 367

Laeopichthys 192

Laeops 8, 51, 104, 189, 192

clarus 193

cypho 193

gracilis 193

guentheri 193, 193*

kitaharae 193

lanceolata 193

macrophthalmus 193, 194, 194*, 196

natalensis 193

nigrescens 193, 194*, 196

nigromaculatus 193, 194, 194*

parviceps 192, 193

pectoralis 193

† rharbensis 16, 21, 26, 193, 195, 196*

sinusarabici 193

† splendens 17, 21, 25, 48, 192, 193, 195, 195*

tungkongensis 193

variegata 193

laevis, Pleuronectes 91

lagoensis, Cynoglossus 343

Laiopteryx 86

lakdoensis, Dageichthys 301

Lambdopsetta 192

lanceolata, Laeops 193

† lapierrei, Arnoglossus 16, 20, 23, 168, 177, 177*, 178

† lapierrei, (Bothidarum) 16, 177

lascaris, Pegusa 18, 19

lascaris, Solea 14, 18, 298, 300, 300*, 301

lata, Platessa 235

laterna, Arnoglossus 14, 18, 24, 27, 122, 166, 167, 168, 168*,

169, 170, 172, 174, 175, 181

latidens, Microstomus 246

latifrons, Citharichthys 137

latifrons, Engyprosopon 202

† latior, Microchirus 16, 19, 21, 25, 283, 288, 288*

† latior, Solea 16, 288

† latisulcatus, Citharus 16

latus, Peltorhamphus 334, 336, 336*

latus, Samariscus 261

leei, Symphurus 362, 364, 364*

† lenticularis, Solea 16

leopardinus, Bothus 158, 160

leotardi, Pleuronectes 168

Lepidoblepharon 34, 35, 37, 44, 48, 49, 64, 71, 84, 85, 86, 210

ophthalmolepis 85, 86*

Lepidopsetta [GILL 1864] 210, 226, 233, 240, 241

bilineata 240, 240*, 241

mochigarei 240

Lepidopsetta [GÜNTHER 1880] 208

Lepidorhombus 11, 34, 48, 49, 80, 89, 90, 92, 93, 250

† angulosus 15, 20, 24, 95, 96, 97, 98*, 99

boscii 10, 18, 94, 95, 95*

† klockenhoffi 16, 20, 24, 95, 99, 99*, 100

† subtriangularis 15, 17, 20, 23, 24, 25, 82, 94, 96, 96*,

97*, 98, 99

whiffiagonis 19, 20, 24, 46*, 92, 93, 94*, 95, 98, 99

leporina, Rhombosolea 253, 254, 255*

Leptolaeops 192

lentiginosus, Rhombus 129

lethostigma, Paralichthys 116, 117, 118, 119*, 121

† leuchsi, Cynoglossus 15, 16, 22, 24, 25, 342, 356, 358*

leucorhynchus, Achiroides 314

levisquamis, Pseudorhombus 125, 126*, 127

Liachirus 323, 328, 329

lida, Cynoglossus 341, 342, 346, 346*

lighti, Cynoglossus 353

ligulatus, Symphurus 362

limanda, Hippoglossoides 220

limanda, Limanda 18, 21, 24, 227, 228*

Limanda 44, 210, 223, 226,

227, 229, 233, 240

† aomoriensis 15, 17

aspera 227, 228, 229*

ferruginea 18, 227, 228, 229*

† ignobilis 16, 21, 23, 227, 228, 229*

limanda 18, 21, 24, 227, 228*

† otomoi 16, 18

proboscidea 227

punctatissima 227

382

Schwarzhans: Pleuronectiformes

sakhalinensis 227

Limandella 238

limandoides, Pleuronectes 220

limandula, Pleuronectes 227

lineata, Solea 318

lineatus, Achirus 273

lineolatus, Cynoglossus 344

lingua, Cynoglossus 340, 342, 351, 352, 352*

linguatula, Citharus 18, 71, 72, 73*, 74, 75

lingula, Monochirus 283

linnei, Hippoglossus 213

lioderma, Pleuronectes 91

Lioglossina 34, 38, 104, 106, 110, 113, 115

oblonga 113, 114, 114*

tetrophthalmus 113, 114, 114*

liolepis, Xystreurys 111, 112, 112*

Liopsetta 210, 226, 230, 233, 235

glacialis 230, 231, 231*

obscura 230, 231, 231*

pinnifasciata 230

putnami 230, 231, 231*

lipophthalmus, Typhlachirus 323

† lobata, Platessa 16

longidorsale, Syacium 136

longimanus, Etropus 153, 154, 155, 155*

longimanus, Samariscus 261

longipelvis, Engyprosopon 202

longipterum, Engyprosopon 202

longleyi, Syacium 138

† longus, Arnoglossus 16, 20, 27, 52, 167, 168, 178, 179*, 184

Lophonectes 104, 165, 185

gallus 185, 185*

Lophopsetta 90

lophoptera, Scianectes 194

Lophorhombus 185

lophotes, Arnoglossus 170

lorentzi, Achirus 273

lubbocki, Symphurus 362

lucapensis, Zebrias 321

lugubris, Chascanopsetta 19, 27, 46*, 135,

207, 207*

lunatus, Bothus 158, 160, 160*

lunulatus, Pleuronectes 159

luscus, Pleuronectes 235

lusitanica, Synaptura 306, 308, 309, 309*

† lusitanicus, Citharus 16, 19, 24, 25, 72, 74*, 75, 82

† lusitanicus, Eucitharus 16, 72

luteum, Buglossidium 19, 281

luteus, Microchirus 282, 283, 284*

luzonensis, Samariscus 261

luzonensis, Symphurus 362

Lyopsetta 48, 49, 210, 214, 217, 219, 220

exilis 18, 21, 27, 217, 218, 218*

maccullochi, Cynoglossus 356

machionessarum, Passer 159

macleayanus, Aseraggodes 325, 326, 327*

macrocephalus, Paraplagusia 348

macrochirus, Nematops 269

macrognathus, Samariscus 261

macrolepidota, Plagusia 351

macrolepidotus, Citharoides 79, 80*

macrolepis, Ammotretis 69

macrolepis, Dexillichthys 311, 312*

macrolepis, Engyprosopon 202

macrolepis, Paracitharus 77, 78*, 79*

macrolepis, Samaris 259

macrolophus, Arnoglossus 176

macrophthalmus, Cynoglossus 342

macrophthalmus, Laeops 193, 194, 194*, 196

macrophthalmus, Symphurus 362

macrops, Citharichthys 147, 148, 148*

macrops, Hippoglossina 109, 110, 110*

macroptera, Engyprosopon 202

macropterus, Rhombus 161

macrorhynchos, Plagusia 352

macrostoma, Arnoglossus 168, 169, 169*

macrostomus, Cynoglossus 342

maculata, Chascanopsetta 207

maculata, Mancopsetta 11, 209, 209*

maculatus, Pleuronectes 92

maculatus, Samariscus 261

maculatus, Solea 302

maculatus, Trinectes 270, 271, 271*

maculifera, Cyclopsetta 141

maculipinna, Monolene 197, 198*, 199

maculipinnis, Arnoglossus 168

maculipinnis, Cynoglossus 342, 356, 357*

maculosus, Pleuronectes [CUVIER 1829] 129

maculosus, Pleuronectes [GIRARD 1856] 120

maderensis, Rhombus 159

maeoticus, Pleuronectes 91

malayanus, Pseudorhombus 125, 127, 127*

maldivensis, Engyprosopon 202

maldivensis, Marleyella 264

maldiviensis, Symphurus 362

malhensis, Parabothus 162

Mancopsetta 10, 34, 39, 40, 41, 44, 45, 104, 105, 208, 210

andriashevi 209

maculata 11, 209, 209*

milfordi 46*, 208*, 209

mancus, Bothus 158, 161, 161*

mangili, Pleuronectes 283

margaritifera, Solea 299

marginata, Synaptura 308

marginatus, Symphurus 362

mariajorisae, Orthopsetta 149

marisrubri, Arnoglossus 168

Marleyella 35, 42, 56, 210, 211, 264, 265

bicolorata 55, 264, 265*

maldivensis 264

marleyi, Cynoglossus 342, 359

marmorata, Synaptura 310

marmoratus, Pardachirus 328, 329, 330, 331*

marmoratus, Symphurus 362

matsubarai, Heteromycteris 332

matsuurae, Reinhardtius 223

maximus, Hippoglossus 213

maximus, Scophthalmus 7, 91, 92*

mazatlanus, Achirus 273, 274, 275*

mbaoensis, Solea 295

† medius, Phrynorhombus 16, 20, 24, 102, 103, 104*

megagnatha, Chascanopsetta 207

megalepis, Poecilopsetta 267

megastoma, Kamoharaia 208

383

Piscium Catalogus, Part Otolithi piscium, Vol. 2

melampetalus, Cynoglossus 351

melanochira, Solea 298

melanogaster, Pleuronectes 117

melanopterus, Plagusia 358

melanorhynchus, Brachirus 312, 314, 315*

melanospilos, Pardachirus 329, 330, 331*

melanostictus, Aseraggodes 325

melanostictus, Psettichthys 242, 242*

melanurus, Symphurus 362

melas, Gymnachirus 278, 279*

melasma, Trichopsetta 190, 191*

melasmatotheca, Symphurus 362

melissi, Bothus 158

mentalis, Hypoclinemus 277, 277*

meridionalis, Symphurus 362

mertensi, Monolene 189, 197

Metoponops 148

Microbuglossus 269, 280, 301

elongatus 302, 303*

heini 302, 303*

ovatus 301, 302, 303*

microcephalus, Pleuronectes 246

microcephalus, Soleichthys 318, 319, 319*, 320, 321

Microchiropsis 281

Microchirus 24, 25, 51, 269, 280, 281, 290, 291, 295

boscanion 281, 282, 283, 284*

frechkopi 282, 292

† frequens 14, 15, 21, 23, 24, 25, 51, 283, 285, 285*, 290

hexophthalmus 282

† kirchbergeanus 14, 16, 17, 18, 21, 24, 25, 51, 283, 286, 287*

† latior 16, 19, 21, 25, 283, 288, 288*

luteus 282, 283, 284*

variegatus 18, 19, 21, 24, 25, 281, 282, 282*, 283, 284, 286, 288

† wienrichi 17, 21, 24, 283, 286, 287, 288, 289*

wittei 282, 292

microchirus, Pleuronectes 283

micrognathus, Chascanopsetta 207

micrognathus, Pseudorhombus 125

microlepidotus, Aseraggodes 325

microlepis, Austroglossus 306, 307

microlepis, Cynoglossus 342

microlepis, Symphurus 362

microphthalmus, Cynoglossus 342

microphthalmus, Neolaeops 166, 166*

microphthalmus, Trinectes 271

microps, Citharichthys 155

microps, Cynoglossus 348

microps, Paralichthys 116, 121, 122*

microstoma, Arnoglossus 168

microstoma, Chascanopsetta 207

microstoma, Monolene 196, 197, 198, 199*

microstoma, Nematops 269

microstoma, Platophrys 204

Microstomus 44, 45, 210, 245, 246, 247

achne 246

kitt 246, 247*

pacificus 19, 21, 246

shuntovi 246

microstomus, Etropus 153, 155, 155*

microstomus, Pleuronectes 246

microtenus, Ancylopsetta 107, 108, 108*

micrurum, Syacium 11, 135, 136, 137*

milfordi, Mancopsetta 46*, 208*, 209

millari, Rhombosolea 254

† minor, Rhombus 16

minor, Symphurus 362

minutus Monochirus 283

† miocenica, Rhombus 16, 18

† miocenicus, Arnoglossus 16, 170, 172

† miocenicus, Citharus 75, 76

† miocenicus, Eucitharus 16, 18, 24, 75

misakius, Pseudorhombus 126

Mischommatus 310

mochigarei, Lepidopsetta 240

mogkii, Engyprosopon 201

mollis, Pleuronectes 271

mongonuiensis, Arnoglossus 185

Monochirus 269, 280, 281, 290

hispidus 290, 291*

monodi, Cynoglossus 342

Monodichthys 332

Monolene 38, 51, 104, 105, 189, 192, 193, 196, 197

antillarum 197, 198*

asaedae 197

atrimana 197

danae 197

dubiosa 197

maculipinna 197, 198*, 199

mertensi 189, 197

microstoma 196, 197, 198, 199*

† priscus 16, 21, 23, 197, 199, 200*

† prudhommae 16, 178

sessilicauda 197, 198*

monopus, Cynoglossus 342, 358, 359*

monopus, Rhombosolea 254

montemaris, Hippoglossina 110

moltoni, Arnoglossus 169

morrowi, Pardachirus 329

mortoniensis, Pleuronectes 129

moseri, Verasper 243, 244

muelleri, Arnoglossus 168

muelleri, Dexillichthys 311

multifasciata, Aesopia 318

multimaculatus, Pseudorhombus 131

multiradiatus, Pseudorhombus 131

multirastris, Arnoglossus 168

multisquamata, Engyprosopon 202

munroi, Zebrias 321

myriaster, Bothus 158, 161, 161*

mystacium, Hippoglossina 110

Myzopsetta 227

nadeshnyi, Acanthopsetta 219, 219*

nalaka, Pleuronectes 58

naresi, Thysanopsetta 206, 206*

nasuta, Solea 298, 300, 300*, 301

natalensis, Engyprosopon 202

natalensis, Laeops 193

natalensis, Poecilopsetta 267, 268*

natalensis, Pseudorhombus 125

nattereri, Achiropsis 280

Neachiropsetta 208

nebularis, Platophrys 159

nebulosus, Apionichthys 280

384

Schwarzhans: Pleuronectiformes

nebulosus, Symphurus 362

neglectus, Pseudorhombus 125, 129, 130*

Nematops 210, 268

chui 269

grandisquama 269, 269*

macrochirus 269

microstoma 269

Nematozebrias 320

Neoetropus 210

Neolaeops 104, 165, 166, 168

microphthalmus 166, 166*

Neorhombus 124

nephelus, Pleuronichthys 247

nicholsi, Nodogymnus 278

nielseni, Samariscus 261

niger, Brachirus 312, 313, 313*

nigrescens, Laeops 193, 194*, 196

nigrescens, Symphurus 19, 22, 26, 360, 362, 367, 367*

nigrolabeculata, Plagusia 356

nigromaculatus, Laeops 193, 194, 194*

nigromanus, Pleuronectes 225

nigropinnatus, Cynoglossus 354

nigrostriolata, Solea 318

Nodogymnus 35, 269, 270, 277, 278

fasciatus 278

nicholsi 278

texae 278, 279*

williamsoni 278

zerbrinus 278

† nolfi, Pseudopardachirolithus 16, 22, 23, 327, 328, 329*

norma, Dorsopsetta 109, 143

Normanetta 328

normani, Aseraggodes 325

normani, Heteromycteris 334

normani, Poecilopsetta 267

normani, Symphurus 362

norvegicus, Phrynorhombus 102, 103, 103*

notata, Hippoglossina 112

notata, Plagusia 348

Notosema 106, 107

novae, Achirus 273

novaecambriae, Paralichthys 131

novaezeelandiae, Bowenia

254

novaezeelandiae, Brachypleura 86, 87, 87*, 226

novaezeelandiae, Peltorhamphus 334, 335, 336*

† novaezeelandiae, Rhombocitharus 16, 20, 27, 81, 83, 84*

novemfasciatus, Symphurus 362

† novus, Arnoglossus 16, 20, 27, 52, 167, 168, 179, 180*, 184

nudipinnis, Colistium 66, 67, 67*, 68

nudus, Gymnachirus 277

nudus, Rhombus 168

† obliqueventralis, Cynoglossus 16, 22, 26, 342, 343, 343*

† obliquus, (Bothidarum) 16, 103

oblonga, Lioglossina 113, 114, 114*

obscura, Liopsetta 230, 231, 231*

oceanica, Limanda 227

ocellaris, Platessa 117

ocellata, Quenselia 282, 290, 292*, 293

ocellata, Taeniopsetta 187, 188*

ocellatus, Aseraggodes 325

ocellatus, Bothus 158, 159, 160*

ocellatus, Hippoglossus 136

ocellatus, Pleuronichthys 247

ocellatus, Psammodiscus 70

ocellatus, Symphurus 362

ocellifer, Pseudorhombus 132

octoculatus, Tosarhombus 203

oculellus, Symphurus 362, 364, 364*

oculocirris, Pseudorhombus 125

oculus, Heteromycteris 332, 333*

Odontolepis 360

† oedelemensis, Psettodes 16, 58, 59, 60

ogilbyi, Cynoglossus 342

oligodon, Pseudorhombus 125, 130, 130*, 134

oligolepis, Plagusia 351

oligolepis, Tarphops 134*, 135

oligomerus, Symphurus 362

olivaceus, Paralichthys 18, 19, 20, 27, 115, 116, 118, 121, 122, 123*

ommaspilus, Symphurus 362

ommatus, Paralichthys 107

Oncopterus 62, 65, 68, 69

darwini 69, 70, 70*

opercularis, Achirus 273

ophthalmolepis, Lepidoblepharon 85, 86*

ophyras, Paralichthys 117

† orbicularis, (Pleuronectidarum) 16

orbicularis, Scaeops 203

orbignyana, Paralichthys 116, 116*, 117

orbisculus, Trichopsetta 190

orientalis, Brachirus 311, 312, 313*, 314

orientalis, Symphurus 362, 366, 366*

ornatus, Achirus 362

ornatus, Samaris 259

Orthopsetta 104, 145, 146, 148, 153

amblybregmatus 149

arctifrons 149, 151, 152*

cornutus 149, 152, 153*

dinoceros 149

fragilis 149, 150*, 151

gymnorhinus 149

mariajorisae 149

sordidus 20, 148, 149, 150*, 151

stigmaeus 20, 149, 149*, 151

xanthostigma 20,149, 151, 151*

orthorhynchus, Hippoglossus 58

os, Cynoglossus 346

† otomoi, Limanda 16, 18

ottonis, Apionichthys 280

ovale, Syacium 55, 56, 136, 137, 138, 139*, 158, 200

ovalis, Ammotretis 69

ovalis, Bothus 158, 161

ovatus, Microbuglossus 301, 302, 303*

oxyrhynchos, Plagusia 358

oxyrhynchus, Arnoglossus 168

pacificus, Microstomus 19, 21, 246

paetulus, Hemirhombus 137

paitensis, Symphurus 362

palad, Platophrys 129

pallasii, Pleuronectes 235

pan, Brachirus 312, 314, 315*

385

Piscium Catalogus, Part Otolithi piscium, Vol. 2

panamensis, Cyclopsetta 19, 20, 22, 141, 143, 144*

panamensis, Solea 271

panoides, Anisochirus 312, 314, 316*

pantherinus, Bothus 158, 159, 159*, 160

papillosum, Syacium 136, 137, 138*, 140

papillosus, Zeugopterus 101

Parabothus 104, 157, 158, 162

amaokai 162

chlorospilus 162, 162*

coarctus 162

kiensis 162

malhensis 162

polylepis 162

taiwanensis 162

violaceus 162

Parachirus 269, 323, 330

xenicus 330

Paracitharus 11, 70, 71, 72, 77, 78

† angustus 11, 15, 20, 25, 77, 78, 79*

macrolepis 77, 78*, 79*

Paradicula 310

paraguayensis, Hypoclinemus 276, 277

Paralichthodes 27, 28, 29, 33, 34, 40, 42, 44, 62, 63, 64, 66, 71, 211

algoensis 62, 64, 65, 65*

Paralichthys 34, 38, 52, 104, 106, 107, 108, 110, 113, 114, 124

adspersus 46*, 116, 117, 121, 121*

aestuarius 116

albiguttata 107, 116, 117, 118*, 119

bicyclophorus 116

brasiliensis 116, 119, 119*, 121

caeruleosticta 116

californicus 18, 20, 114, 115, 116, 120, 120*, 121, 122

dentatus 116, 117, 117*, 121

fernandezianus 116

hilgendorfi 116

isocles 115, 116,

122, 123*, 125

lethostigma 116, 117, 118, 119*, 121

microps 116, 121, 122*

olivaceus 18, 19, 20, 27, 115, 116, 118, 121, 122, 123*

orbignyana 116, 116*, 117

shmitti 116

squamilentus 107, 116, 117, 118, 118*, 119

triocellatus 116

tropicus 116, 119, 119*

vorax 116

woolmani 116

Paralimanda 265

Paraplagusia 338, 339, 340, 341, 342, 348, 359

† alta 15, 356

bilineata 18 , 348

japonica 18, 348

† roseni 17, 356

Pardachirus 36, 45, 269, 323, 326, 327, 328

hedleyi 329, 330, 331*

marmoratus 328, 329, 330, 331*

melanospilos 329, 330, 331*

morrowi 329

pavoninus 19, 22, 27, 329, 330, 331*

poropterus 329

Parophrys 48, 49, 210, 226, 232, 233

vetulus 19, 21, 47*, 232, 233*

parviceps, Laeops 192, 193

parvimanus, Rhombus 159

parvus, Symphurus 362

passarinus, Pleuronectes 2

passer, Pleuronectes 235

patagonicus, Paralichthys 116

† patens, Dicologlossa 16, 18, 19, 21, 24, 25, 294, 296, 297*

† patens, Solea 16, 296

paulistanus, Trinectes 271, 272*

pavo, Rhombus 161

pavonina, Platessa 91

pavoninus, Pardachirus 19, 22, 27, 329, 330, 331*

pectoralis, Austroglossus

306, 307, 307*

pectoralis, Laeops 193

pegusa, Solea 300

Pegusa 296, 297

lascaris 18, 19

Pelecanichthys 104, 206, 207

crumenalis 208

pelicanus, Symphurus 362

pellegrini, Cynoglossus 348

pellucidus, Thyris 197

Peloria 157

Pelotretis 27, 35, 40, 210, 250, 251, 252

flavilatus 251, 252, 253*

Peltorhamphus 12, 35, 36, 40, 65, 210, 269, 330, 331, 334

† flexodorsalis 15, 22, 27, 334, 335, 337*

† fordycei 15, 22, 27, 334, 337, 338*

latus 334, 336, 336*

novaezeelandiae 334, 335, 336*

tenuis 19, 22, 27, 334, 336, 338*

penescalaris, Zebrias 321

pennatus, Grammatobothus 163

† pentagonalis, Brachypleura 16, 20, 24, 86, 87, 88, 88*

† pentagonalis, (Pleuronectidarum) 16, 88

pentophthalmus, Pseudorhombus 19, 27, 125, 132, 132*

perarcuatus, Pleuronectes 240

percocephala, Platessa 122

Perissias 38, 104, 105, 158, 189, 192

taeniopterus 192

persimilis, Aseraggodes 325

peruvianus. Etropus 153

Phrynorhombus 10, 11, 89, 100, 102

† bassolii 15, 102

† medius 16, 20, 24, 102, 103, 104*

norvegicus 102, 103, 103*

regius 102, 103

Phyllichthys 269, 310, 314, 315, 316

punctatus 314, 315,

316, 316*

sclerolepis 315

sejunctus 315

picta, Plagusia 367

pictus, Pleuronectes 161

pilosa, Solea 273

piger, Symphurus 362

pimetorum, Cleisthenes 217

pinangensis, Cantoria 351

pinguis, Pleuronectes 223

pinnifasciata, Liopsetta 230

pinnifasciatus, Azygopus 263, 264, 264*

Plagiopsetta 56, 210, 254, 257, 263

glossa 257, 258, 258*

plagiusa, Symphurus 362*, 363

Plagiusa 360

plagusia, Symphurus 362, 362*

386

Schwarzhans: Pleuronectiformes

Plagusia 360

planus, Pleuronectes 238

platessa, Pleuronectes 7, 19, 21, 24, 51, 52, 232, 233, 234*, 235

Platessa 232

† lobata 16

† sector 17

platessoides, Hippoglossoides 19, 21, 24, 220, 221*

Platichthys 53, 210, 226, 235, 236, 238, 241

flesus 18, 21, 24, 53, 55*, 235, 237*

stellatus 19, 21, 53, 54*, 235, 236, 237*, 241

platophrys, Citharichthys 147

Platophrys 157, 158

Platotichthys 157

Platysomatichthys 221

plebeia, Rhombosolea 52, 252, 253, 254, 255*

Pleuronectes 44, 210, 226, 232, 233, 235

† boerialensis 15

† elongatus 15, 18

pallasii 235

platessa 7, 19, 21, 24, 51, 52, 232, 233, 234*, 235

† sectoroides 17

† vulsus 17

(Pleuronectidarum)

† acuminatus 15

† concavus 15

† fangariensis 15, 18

† hunyadensis 16, 18

† irregularis 16, 18, 22

† orbicularis 16

† pentagonalis 16

† splendens 17

† subrostratus 17

† syacioides 17

† temputulensis 17

Pleuronichthys 44, 45, 210, 245, 246

coenosus

246, 247, 248*

cornutus 18, 21, 27, 247

decurrens 247, 248, 248*

nephelus 247

ocellatus 247

ritteri 19, 21, 247, 249, 250*

verticalis 247, 249, 249*

plinthus, Poecilopsetta 266*, 267

Pluviopsetta 210

Pnictes 269, 279, 280

asphyxiatus 280

podas, Bothus 157, 158, 159, 159*, 160

Poecilopsetta 10, 45, 210, 264, 265, 268

albomaculata 266*, 267

albomarginata 267

beani 266*, 267

colorata 265, 267

hawaiiensis 267

inermis 267

megalepis 267

natalensis 267, 268*

normani 267

plinthus 266*, 267

praelongo 266*, 267

vaynei 267

zanzibarensis 267, 268*

poecilurus, Rhombus 203

pola, Platessa 246

† polonica, Bathysolea 16, 21, 25, 305*, 306

polylepis, Parabothus 162

polyophthalmus, Grammatobothus 162, 163, 163*, 164

polyspilus, Arnoglossus 168

polyspilus, Rhombus 129

polytaenia, Plagusia 346

Pomatopsetta 219

ponticus, Hippoglossus 213

ponticus, Scophthalmus 91

poropterus, Pardachirus 329

potous, Pleuronectes 352

† Praearchirolithus 12, 13, 269, 323, 327

† schultzei 17, 21, 23, 323, 324, 324*, 328

praecisus, Cynoglossus 353

praelongo, Poecilopsetta 266*, 267

† premaxima, Psetta 16

† priscus, Monolene 16, 21, 23

proboscidea, Limanda 227

proboscideus, Heteromycteris 332

profunda, Psettina 186

profundicola, Bathysolea 305, 305*, 306

prognathus, Chascanopsetta 207

prolatinaris, Symphurus 362

prorigera, Chascanopsetta 207

Protopsetta 216

† prudhommae, Arnoglossus 16, 20, 24, 168, 177*, 178

† prudhommae, Monolene 16, 178

Psammodiscus 62, 65, 70

ocellatus 70

Psetta 90

† premaxima 16

Psettichthys 210, 241, 242

melanostictus 242, 242*

Psettina 104, 165, 186

brevirictis 186, 187*

gigantea 186

iijimae 186*, 187

profunda 186

tosana 186

variegata 186

Psettinella 186

Psettodes 10, 12, 25, 27, 28, 34, 42, 48, 57, 62, 63

† bavayi 15, 19, 23, 58, 61, 62*, 64

belcheri 57, 58, 59*

bennettii 58

† collatus 15, 16, 17, 19, 23, 58, 59, 60*, 61*

erumei 58, 59*

† oedelemensis 16, 58, 59, 60

† spinosus 17, 58, 59, 60

Psettylis 157

Pseudaesopia 269, 316, 318, 319, 321

crossolepis 320

japonica 320, 320*

regani 319, 320

Pseudaustroglossus 306

Pseudocitharichthys 157

Pseudomancopsetta 208

† Pseudopardachirolithus 12, 13, 269, 323, 327

† nolfi 16, 22, 23, 327, 328, 329*

† sulci 17, 22, 24, 25, 327, 328, 329*

Pseudoplatichthys 210

Pseudopleuronectes 210, 226, 233, 238, 240, 241, 245

americanus 238, 239*

387

Piscium Catalogus, Part Otolithi piscium, Vol. 2

herzensteini 238, 239*

yokohamae 238, 239*

Pseudorhombus 27, 34, 38, 42, 45, 52, 104, 106, 110, 116, 124,

134, 135, 136

annulatus 125, 130, 130*, 133

argus 125, 132*, 133

arsius 124, 125, 127, 129, 129*, 134

cinnamoneus 125, 126, 126*

diplospilus 125

dupliciocellatus 125, 129, 130*

elevatus 125, 131, 131*

† helvecianus 16

javanicus 125, 127, 128*, 129

jenynsii 125, 131, 131*, 132

levisquamis 125, 126*, 127

malayanus 125, 127, 127*

micrognathus 125

natalensis 125

neglectus 125, 129, 130*

oculocirris 125

oligodon 125, 130, 130*, 134

pentophthalmus 19, 27, 125, 132, 132*

quinquocellatus 125

spinosus 125

tenuirastrum 125, 132, 132*, 133

triocellatus 125, 131, 132, 133, 133*

† weinfurteri 17, 18, 20, 25, 125, 133, 133*

pterospilotus, Symphurus 362

punctatissima, Limanda 227

punctatissima, Synaptura 309

punctatus, Cynoglossus 353

punctatus, Phyllichthys 314, 315, 316, 316*

punctatus, Zeugopterus 19, 20, 24, 100*, 101

puncticeps, Cynoglossus 342, 356, 357*, 358

purpureomaculatus, Areliscus 348

pusilla, Platessa 238

pusillus, Symphurus 362

putnami, Liopsetta 230, 231, 231*

† quadratus, Arnoglossus 16, 21, 26, 167, 168, 170, 174, 175*

quadridens, Pleuronectes 246

quadrilineatus, Cynoglossus 342, 344, 346*

quadriocellata, Solea 293

quadrituberculatus, Pleuronichthys 248

quadrocellata, Ancylopsetta 106, 107, 107*

quagga, Zebrias 321, 322, 323*

Quenselia 24, 25, 44, 269, 280, 281, 282, 290, 295

† cornuta 15, 21, 25, 26, 44, 291, 292, 293, 293*, 295

ocellata 282, 290, 292*, 293

teophila 292*, 293

quenselii, Pleuronectes 246

querna, Cyclopsetta 109, 141, 142*, 143

quinquelineatus, Cynoglossus 344

quinquocellatus, Pseudorhombus 125

radula, Taeniopsetta 187, 188, 188*

† radwanskae, Grammatobothus 16, 20, 25, 163, 164*

Ranularia 106

raoulensis, Engyprosopon 202

raptator, Trachypterophrys 207

rasile, Xystreurys 112, 113*

regani, Engyprosopon 202

regani, Pseudaesopia 319, 320

regani, Symphurus 362

regius, Phrynorhombus 102, 103

Reinhardtius 10, 11, 42, 48, 49, 210, 211, 214, 215, 220, 221

hippoglossoides 47*, 221, 223, 224*

Rendahlia 36, 269, 330, 332, 339

hartzfeldi 332, 334, 335*

jaubertensis 332, 333, 334, 335*

retiaria, Rhombosolea 253, 254, 257*

reticulatus, Symphurus 362

† rharbensis, Laeops 16, 21, 26, 193, 195, 196*

† rhenanus, Rhombocitharus 15, 16, 17, 20, 23, 24, 80, 81, 81*

† rhenanus, Rhombus 16, 81, 96

Rhinoplagusia 340

† altus 356

Rhinosolea 12, 269

rhomaleus, Arelia 347

Rhombiscus 124

† Rhombocitharus 12, 13, 23, 24, 70, 80, 84

† biaculeatus 15, 20, 23, 81

† cauneillensis 15, 20, 23, 81, 83, 83*

† circularis 15, 20, 23, 81, 83

† novaezeelandiae 16, 20, 27, 81, 83, 84*

† rhenanus 15, 16, 17, 20, 23, 24, 80, 81, 81*

† rhomboides 17, 20, 23, 81, 82*, 83

Rhomboides 90

† rhomboides, (Bothidarum) 17

† rhomboides, Rhombocitharus 17, 20, 23, 81, 82*, 83

rhomboides, Rhombus 159

rhomboides, Solea 159

Rhomboidichthys 157, 158

Rhombosolea 35, 39, 40, 42, 48, 49, 51, 210, 251, 252

leporina 253, 254, 255*

plebeia 52, 252, 253, 254, 255*

retiaria 253, 254, 257*

tapirina 47*, 52, 53, 55*, 253, 254, 256*

Rhombus 90

† altus 15, 17, 26

† corius 15, 17

† foliformis 15, 18

† karaganensis 16

† konkensis 16, 18

† minor 16

† miocenica 16, 18

rhombus, Scophthalmus 90, 91, 93*

rhytisma, Symphurus 362

rikuzenius, Dexistes 228, 230, 230*

rimosus, Etropus 153

ritteri, Pleuronichthys 19, 21, 247, 249, 250*

robinsi, Bothus 158

robinsoni, Plagusia 349

robustus, Cynoglossus 342, 351, 352, 352*, 353

robustus, Hippoglossoides 220

† roseni, Paraplagusia 17, 356

† rosenthalensis, Bothus 17, 101

† rosenthalensis, Zeugopterus 17, 20, 23, 101, 101*

roseus, Pleuronectes 235

rostrata, Myzopsetta 228

rostratum, Engyprosopon 202

rostratus, Ammotretis 68, 69, 69*

388

Schwarzhans: Pleuronectiformes

† rotunda, Solea 17, 19, 21, 25, 298, 299, 299*

† rotundus, Gobius 17, 299

† rotundus, Solea 17, 18

roulei, Cynoglossus 347

rueppelli, Arnoglossus 10, 167, 168, 176, 176*, 177

rugosus, Platichthys 236

rumulo, Bothus 159

russellii, Platessa 129

russellii, Solea 308

sakhalinensis, Limanda 227

salinarum, Brachirus 312

Samaris 34, 35, 40, 44, 45, 56, 210, 254, 258

costae 259

cristatus 258, 259, 260*

macrolepis 259

† validus 17, 21, 27, 259, 260*

Samariscus 8, 10, 56, 210, 254, 258

asanoi 261

corallinus 261

desoutterae 261

fasciatus 261

filipectoralis 261

huysmani 261, 262, 263*

inornatus 261

japonicus 261, 262*

latus 261

longimanus 261

luzonensis 261

macrognathus 261

maculatus 261

nielseni 261

sunieri 261, 263*

triocellatus 52, 261, 262, 263*

xenicus 261

sanctilaurenti, Engyophrys 190, 191, 192*

sauvignyi, Synaptura 301

saxatilis, Pleuronectes 103

saxicola, Pleuronectes 225

sayademalhensis, Symphurus 362

sayaensis, Arnoglossus 168

scabra, Trinectes 271

Scaeops 201

scalaris, Zebrias 321

scapha, Caulopsetta 182, 183, 183*, 184

schrenki, Limanda 238

† schuberti, Citharus 17, 19, 25, 72, 76, 76*

† schuberti, Eucitharus 17, 76

† schultzei, Praearchirolithus 17, 21, 23, 323, 324, 324*, 328

† schultzei, (Soleidarum) 17, 324, 328

schultzi, Symphurus 362

Scianectes 192

Scidorhombus 166

sclerolepis, Phyllichthys 315

Scophthalmus 25, 34, 89, 90, 100

aquosus 91, 92, 93*

maximus 7, 91, 92*

rhombus 90, 91, 93*

scutifer, Pleuronectes 236

scutum, Achirus 273, 274, 275*

sealarki, Cynoglossus 341, 342, 355, 355*

sechellensis, Engyprosopon 202

† sector, Platessa 17

† sectoroides, Pleuronectes 17

sejunctus, Phyllichthys 315

selheimi, Brachirus 312

† semen, Bothus 17

semifasciatus, Cynoglossus 342, 358, 359*

semilaevis, Cynoglossus 342, 347, 348, 349*

senegalensis, Cynoglossus 342, 344, 345*

senegalensis, Solea 19, 297, 298, 298*

sentus, Engyophrys 191

septempes, Engyprosopon 202

septemstriatus, Symphurus 362, 366, 366*

septentrionalis, Hippoglossus 213

serratus, Rhombus 159

setiger, Dexillichthys 311

setiger, Rhombus 103

shmitti, Paralichthys 116

shuntovi, Microstomus 246

siammakuti, Soleichthys 318

sibogae, Cynoglossus 353

† simplex, Solea 17, 18

simulator, Cynoglossus 344

sindensis, Cynoglossus 344

sinensis, Tephrinectes 63, 64*

sinicus, Cynoglossus 344

sinusarabici, Aseraggodes 325

sinusarabici, Cynoglossus 342

sinusarabici, Laeops 193

slavae, Achiropsetta 209

smithi, Aseraggodes 325

smithi, Engyprosopon 202

smithi, Platophrys 161

smithii, Zebrias 320

solea, Solea 7, 14, 19, 21, 24, 27, 125, 296, 297, 298, 299, 300, 301*

Solea 35, 51, 269, 280, 296, 297, 302

aegyptiaca 297, 298, 301*

† angulata 15, 17

† antiqua 286

† approximata 15, 23, 24, 285, 286, 288, 290

† balangoensis 15, 17

† bartonensis 15

bleekeri 297, 298

† corpulentus 15

† cottreaui 15

fulvomarginata 298

† guestfalica 16, 82

impar 298

† kirchbergeana 16, 286

kleini 298, 301, 301*

† kokeni [BASSOLI 1906]16, 172, 296

† kokeni [SCHUBERT 1906] 16, 296

lascaris 14, 18, 298, 300, 300*, 301

† latior 16, 288

† lenticularis 16

nasuta 298, 300, 300*, 301

† patens 16, 296

† rotunda 17, 19, 21, 25, 298, 299, 299*

† rotundus 17, 18

senegalensis 19, 297, 298, 298*

† simplex 17, 18

solea 7, 14, 19, 21, 24, 27, 125, 296, 297, 298, 299, 300, 301*

† solitarius 17

389

Piscium Catalogus, Part Otolithi piscium, Vol. 2

† songgoensis 17, 18

stanalandi 298

† subglaber 17

† subvulgaris 17, 286, 287

† sulci 17

† taureri 17, 172

† tenuis 17, 18, 195

triophthalma 297, 298, 299*

soleaeformis, Rhombus 137

(Soleidarum)

† schultzei 17

Soleichthys 48, 49, 269, 316, 318, 320, 321

heterorhinos 318, 319*

microcephalus 318, 319, 319*, 320, 321

siammakuti 318

Soleonasus 269, 279, 280

finis 280

Soleotalpa 279

† solitarius, Solea 17

† songgoensis, Solea 17, 18

sordidus, Citharichthys 19

sordidus, Orthopsetta 20, 148, 149, 150*, 151

sorsogonensis, Typhlachirus 323

Sphagomorus 57

spilopterus, Citharichthys 145, 146*, 147

spilurus, Rhomboidichthys 203

Spinirhombus 124

spinosus, Pleuronectes 161

† spinosus, Psettodes 17, 58, 59, 60

spinosus, Pseudorhombus 125

† splendens, Hippoglossoides 195

† splendens, Laeops 17, 21, 25, 48, 192, 193, 195, 195*

† splendens, (Pleuronectidarum) 17, 195

squamilentus, Paralichthys 107, 116, 117, 118, 118*, 119

stampfli, Citharichthys 146*, 147

stanalandi, Solea 298

stellatus, Platichthys 19, 21, 53, 54*, 235,

236, 237*, 241

stelleri, Glyptocephalus 225

stellosus, Rhombus 91

stenolepis, Hipoglossus 19, 21, 213, 214, 214*

stigmaeus, Citharichthys 19

stigmaeus, Orthopsetta 20, 149, 149*, 151

stigmatias, Paralichthys 107

stomata, Hippoglossina 110, 111, 111*

stomias, Atherestes 19, 21, 215, 216*

Strabozebrias 320

Strandichthys 310

strictus, Symphurus 362

† subglaber, Solea 17, 96

† subrostratus, (Pleuronectidarum) 17

† subtriangularis, Lepidorhombus 15, 17, 20, 23, 24, 25, 82,

94, 96, 96*, 97*, 98, 99

† subvulgaris, Solea 17, 286, 287

† sulci, Pseudopardachirolithus 17, 22, 24, 25, 327, 328, 329*

† sulci, Solea 17, 328

sumatrana, Plagusia 358

sumatranus, Rhombus 159

sumichrasti, Citharichthys 147

sumptuosus, Symphurus 362

sundaicus, Brachirus 312

sunieri, Samariscus 261, 263*

surinamensis, Pleuronectes 160

suyeni, Cynoglossus 342

swinhonis, Pseudorhombus 122

Syacium 11, 34, 38, 42, 44, 104, 135, 145, 158, 200

† dominicensis 15, 20, 22, 136, 139, 140*

gunteri 136, 138, 139*

longidorsale 136

micrurum 11, 135, 136, 137*

ovale 55, 56, 136, 137, 138, 139*, 158, 200

papillosum 136, 137, 138*, 140

† syacioides 11, 17, 20, 25, 136, 140, 141*

†

syacioides, (Pleuronectidarum) 17, 140

† syacioides, Syacium 11, 17, 20, 25, 136, 140, 141*

Symboulichthys 157

Symphurus 8, 10, 22, 36, 40, 42, 51, 338, 339, 342, 359, 360, 361

arabicus 362

arawak 362

atramentatus 362, 365, 366*

atricaudus 18, 22, 52, 361, 362, 364, 364*

australis 362

bergi 362

callopterus 362

caribbeanus 362

chabanaudi 362*, 363

civitatus 362, 364, 364*

diabolicus 362

diomedianus 362

elongatus 362*, 363

fallax 362

fasciolaris 362

fuscus 362

gilesi 360, 362, 366*, 367

ginsburgi 362

gorgonae 362

holothuriae 362

jenynsi 362

kyaropterygium 362

leei 362, 364, 364*

ligulatus 362

lubbocki 362

luzonensis 362

macrophthalmus 362

maldiviensis 362

marginatus 362

marmoratus 362

melanurus 362

melasmatotheca 362

meridionalis 362

microlepis 362

minor 362

nebulosus 362

nigrescens 19, 22, 26, 360, 362, 367, 367*

normani 362

novemfasciatus 362

ocellatus 362

oculellus

362, 364, 364*

oligomerus 362

ommaspilus 362

orientalis 362, 366, 366*

paitensis 362

parvus 362

pelicanus 362

piger 362

plagiusa 362*, 363

plagusia 362, 362*

390

Schwarzhans: Pleuronectiformes

prolatinaris 362

pterospilotus 362

pusillus 362

regani 362

reticulatus 362

rhytisma 362

sayademalhensis 362

schultzi 362

septemstriatus 362, 366, 366*

strictus 362

sumptuosus 362

tesselatus 362

trewavasae 362, 363, 363*, 364

trifasciatus 362

undatus 362

undecimplerus 362

urospilos 362

variegatus 362

varius 362

vittatus 362

williamsi 362, 365, 366*

woodmasoni 362

Synaptura 35, 44, 45, 269, 306, 308

albomaculata 308*, 309

cadenati 308

commersoniana 18, 308, 308*

lusitanica 306, 308, 309, 309*

marginata 308

Synapturichthys 296

synapturoides, Zebrias 321, 322, 322*

Synclidopus 324, 326

taedifer, Bascanius 176

Taeniopsetta 38, 104, 165, 187

† dorsolobata 15, 21, 188, 189*

ocellata 187, 188*

radula 187, 188, 188*

taeniopterus, Perissias 192

taivanus, Spinirhombus 126

taiwanensis, Parabothus 162

Tanakius 210, 223

kitaharae 223, 224, 225*

tapeinosoma, Arnoglossus 167, 168, 176, 176*

, 177

tapirina, Rhombosolea 47*, 52, 53, 55*, 253, 254, 256*

Tapirisolea 68

Taratretis 62, 65, 70

derwentensis 70

Tarphops 19, 27, 38, 45, 104, 124, 134

elegans 135

oligolepis 134*, 135

† taureri, Arnoglossus 16, 17, 18, 21, 24, 25, 168, 170, 172, 173*

† taureri, Solea 17, 172

† temputulensis, (Pleuronectidarum) 17

tenuirastrum, Pseudorhombus 125, 132, 132*, 133

tenuis, Areliscus 353

tenuis, Arnoglossus 168

tenuis, Peltorhamphus 19, 22, 27, 334, 336, 338*

tenuis, (Pleuronectiformorum) 195

† tenuis, Solea 17, 18, 195

teophila, Quenselia 292*, 293

Tephrinectes 27, 28, 29, 33, 34, 38, 40, 44, 53, 62, 63, 66, 104, 105

sinensis 63, 64*

Teratorhombus 124

tesselatus, Symphurus 362

tetrophthalmus, Lioglossina 113, 114, 114*

texae, Nodogymnus 278, 279*

† texana, Eosolea 17

texturatus, Aseraggodes 325

thompsoni, Apsetta 254

thori, Arnoglossus 168, 169, 171*

Thyris 197

Thysanopsetta 34, 38, 40, 42, 45, 104, 105, 205, 206, 208

naresi 206, 206*

tosana, Psettina 186

Tosarhombus 104, 199, 203

octoculatus 203

Trachypterophrys 207

† transitus, Cyclopsetta 17, 20, 22, 143, 145*

trewavasae, Symphurus 362, 363, 363*

, 364

Trichobrachirus 312

trichodactylus, Pleuronectes 290

trichodactylus, Solea 312

tricholepis, Achiropsetta 210

Trichopsetta 38, 104, 105, 189, 190, 191, 192

caribbaea 190

melasma 190, 191*

orbisculus 190

ventralis 46*, 190, 191*

trichospilus, Achirus 273

tricirrhatus, Bothus 158

trifasciatus, Symphurus 362

trigrammus, Cynoglossus 342, 348, 349*

Trinectes 8, 269, 270, 273

fimbriatus 271

fluviatilis 271

fonsecensis 271, 272, 272*

inscriptus 271

maculatus 270, 271, 271*

microphthalmus 271

paulistanus 271, 272*

triocellatus, Paralichthys 116

triocellatus, Pseudorhombus 125, 131, 132, 133, 133*

triocellatus, Samariscus 52, 261, 262, 263*

triophthalma, Solea 297, 298, 299*

tropicus, Paralichthys 116, 119, 119*

trulla, Plagusia 344

Trulla 340, 341, 342, 348

tshusanensis, Cynoglossus 353

tuberculatus, Pleuronectes 91

tubifera, Solea 318

tudori, Ammotretis 69, 69*

tungkongensis, Laeops 193

turbot, Pleuronectes 91

Typhlachirus 269, 316, 323

lipophthalmus 323

sorsogonensis 323

uhleri, Citharichthys 147

ui, Engyprosopon 19, 135

ui, Scaeops 204

umborsus, Platichthys 240

uncinata, Solea

391

Piscium Catalogus, Part Otolithi piscium, Vol. 2

undatus, Symphurus 362

undecimplerus, Symphurus 362

unicolor, Cynoglossus 342, 350*, 351

unicolor, Soleotalpa 280

unicornis, Citharichthys 152

unimaculatus, Rhombus 103

uniocellatus, Pleuronectes 103

Uropsetta 114

urospilos, Symphurus 362

Usinostia 340

† validus, Samaris 17, 21, 27, 259, 260*

Vanstraelenia 35, 269, 280, 281, 302, 305

chirophthalma 303, 304, 304*

insignis 303, 304, 304*

† varians, Citharichthys 17

variegata, Laeops 193

variegata, Psettina 186

variegatus, Mirochirus 18, 19, 21, 24, 25, 281, 282, 282*, 283,

284, 286, 288

variegatus, Symphurus 362

variegatus, Verasper 244, 244*

varius, Symphurus 362

vaynei, Poecilopsetta 267

Velifracta 63

ventralis, Trichopsetta 46*, 190, 191*

ventrocellatus, Cephalopsetta 135

Veraequa 246

Verasper 34, 210, 243, 245

moseri 243, 244

variegatus 244, 244*

Verecundum 111

versicolor, Cynoglossus 353

verticalis, Pleuronichthys 247, 249, 249*

vetulus, Parophrys 19, 21, 47*, 232, 233*

victoriae, Pleuronectes 254

villosa, Brachirus 312

violaceus, Parabothus 162

vittatus, Symphurus 362

vorax, Paralichthys 116

vorax, Pseudorhombus 119

vulgaris, Hippoglossus 213

vulgaris, Limanda 227

vulgaris, Platessa 235

vulgaris, Solea 19, 296, 300

† vulsus, Pleuronectes 17

waikyai, Arnoglossus 132

waitei, Arnoglossus 168, 176*, 177

wandersi, Cynoglossus 342

† weileri, Sebastes 17, 82

† weileri, (Bothidarum) 17, 82

† weinfurteri, Pseudorhombus 17, 18, 20, 25, 125, 133, 133*

whiffiagonis, Lepidorhombus 19, 20, 24, 46*, 92, 93, 94*, 95,

98, 99

whitakeri, Aseraggodes 325

Whitleyia 310

† wienrichi, Microchirus 17, 21, 24, 283, 286, 287, 288, 289*

williamsi, Symphurus 362, 365, 366*

williamsoni, Nodogymnus 278

wittei, Microchirus 282, 292

wolffii, Rhombus 122

woodmasoni, Symphurus 362

woolmani, Paralichthys 116

xanthosticta, Brachypleura 87

xanthostigma, Citharichthys 19

xanthostigma, Orthopsetta 20, 149, 151, 151*

xenandrus, Engyprosopon 201, 202, 202*

xenicus, Parachirus 330

xenicus, Samariscus 261

Xenobuglossus 294

† xenosulcis, Brachypleura 17, 20, 26, 86, 87, 88, 89*

Xystreurys 38, 104, 106, 111

liolepis 111, 112, 112*

rasile 112, 113*

Xystrias 212

yokohamae, Pseudopleuronectes 238, 239*

ypsigrammus, Bothus 158

zachirus, Glyptocephalus 19, 21, 47*, 225, 226*, 227*

zanzibarensis, Cynoglossus 342, 355, 355*

zanzibarensis, Poecilopsetta 267, 268*

zanzibarica, Brachirus 312

zebra, Zebrias

321, 322, 323*

Zebrias 35, 45, 269, 316, 318, 320, 323

altipinnis 321, 321*

annadalei 321

cancellatus 321, 322, 322*

cochinensis 321

craticulus 321

fasciatus 321

keralensis 321

lucapensis 321

munroi 321

penescalaris 321

quagga 321, 322, 323*

scalaris 321

synapturoides 321, 322, 322*

zebra 321, 322, 323*

zebrinus, Achirus 273

zerbrinus, Nodogymnus 278

Zeugopterus 10, 11, 34, 45, 89, 100

punctatus 19, 20, 24, 100*, 101

† rosenthalensis 17, 20, 23, 101, 101*

Zevaia 282, 290, 291, 295

zonatus, Ammotretis 69

Piscium Catalogus

ISSN 0724-9012

A continuing file of all recent and fossil fishes

from a paleoichthyological point of view

Part

OTOLITHI PISCIUM

vol. 1 A comparative morphological treatise

of recent and fossil otoliths

of the family Sciaenidae (Perciformes)

by Werner SCHWARZHANS

pp. 1-245, 406 figs., July 1993,

ISBN 3-923871-70-8, DM 240,–;

now

DM 120,–/ ˜ 61,36.

vol. 2 A comparative morphological treatise

of recent and fossil otoliths

of the of the order Pleuronectiformes

by Werner SCHWARZHANS

pp. 1-392, 1021 figs., April 1999,

ISBN 3-931516-54-7, DM 150,–/ ˜ 76,69.

vol. 3 is in preparation and will deal with

recent and fossil otoliths of the

Gadiformes and Batrachoidiformes

Further volumes are being envisaged and

will be published in 2 to 3 year intervals,

dealing with

Ophidiiformes

Beryciformes and Zeiformes

Osmeriformes and Stomiformes

Myctophiformes

Trachinoidei and Notothenioidei

For orders please contact

Verlag Dr. Friedrich Pfeil

P.O. Box 65 00 86, D-81214 München

Tel. (089) 74 28 270 – Fax (089) 72 42 772 – E-Mail 100417.1722@compuserve.com

Piscium

catalogus

is a continuing

ﬁ le of all

recent and

fossil ﬁ shes

from a

paleoichthyological

point of view

ISSN 0724-9012

ISBN 3-931516-54-7

Teleostean otoliths reveal diverse Plio-Pleistocene fish assemblages in coastal Georgia (Glynn County)

Article

Aug 2018

Extensive bulk sampling at seven Plio-Pleistocene sites spanning approximately 4.5 Ma to 120,000 years ago in age near Brunswick, Glynn County, Georgia, produced 1,803 teleostean otoliths. The otolith assemblage was relatively diverse with 50 taxa (representing 18 families) of Plio-Pleistocene teleosts. The otoliths represented mainly shallow-marine fishes, which were all extant except for four species. The assemblage was dominated by 16 sciaenid taxa that represented 65.8% of the total number of otoliths. The Plio-Pleistocene otoliths indicated fishes that are almost identical to the marine fishes from present-day coastal Georgia. The teleostean otoliths are considered especially important for several reasons. This study represents the first description of fish otoliths from the Plio-Pleistocene of coastal Georgia and describes the bony fishes present from approximately 4.5 Ma (Raysor Marl equivalent) to 120,000 years ago (late Pleistocene). This time interval includes the late Neogene climatic changes as well as the glacial-interglacial climatic cycles in North America. Also, the preservation of aragonitic otoliths is rare in coastal Georgia given the very high water table and the intense and rapid weathering. Furthermore, there is a paucity of Plio-Pleistocene fossils, especially bony fishes, in coastal Georgia related to various geological constraints such as highly erosive transgressive sequences. The Plio-Pleistocene otolith assemblage from coastal Georgia contains 13 families representing 28 taxa not recognized by skeletal fossils in Georgia. Although the Ariidae and Sciaenidae were previously recognized based on skeletal fossil material in Georgia, there are 14 newly reported taxa based on otoliths in these families (1 and 13 respectively) including Protosciaena kirbyorum n. sp., the first fossil species of this genus in the U.S. Otolith data also verified fishes previously indicated by skeletal remains and provided greater specificity in several cases.

Early Pliocene otolith assemblages from the outer-shelf environment reveal the establishment of mesopelagic fish fauna over 3 million years ago in southwestern Taiwan

Article

Full-text available

Sep 2023

Understanding the diversity of deep-sea fish fauna based on otoliths in the tropical and subtropical West Pacific has been limited, creating a significant knowledge gap regarding regional and temporal variations in deep-sea fish fauna. To address this gap, we collected a total of 122 bulk sediment samples from the Lower Pliocene Gutingkeng Formation in southwestern Taiwan to reconstruct the otolith-based fish fauna. Using planktonic foraminiferal biostratigraphy, we determined the age of the samples to be 5.6 to 3.1 Ma. A total of 8314 otoliths were assigned to 64 different taxa from 33 families, including the discovery of one new genus, Gutingichthys gen. nov., and three new species: Benthosema duanformis sp. nov., Benthosema parafibulatum sp. nov., and Gutingichthys changi sp. nov. Comparisons with other regional otolith-based assemblages highlighted the exceptional diversity of our collection, making it the most diverse fossil fish fauna reported from Taiwan to date. Otolith diversity analysis revealed very few taxa were dominant in the assemblage, particularly the mesopelagic Myctophidae, with a wide variety of minor taxa. The co-occurrence of shallow-water elements suggests episodic storm events as a potential source. The predominance of deep-sea and oceanic fishes indicated an outer-shelf to upper slope environment, resembling the modern outer-shelf and upper slope fish fauna in the region. Our findings suggest an early establishment and persistent presence of the mesopelagic fish community since the Early Pliocene. Further investigations of the Upper Miocene and Pleistocene sections of the Gutingkeng Formation would provide valuable insights into the evolution of deep-sea fish fauna in the area.

2023 Schwarzhans- Geology and otolith-based fisg fauna, Pliocene NW-Morocco

Article

Full-text available

Apr 2023

The coquina on the banks of the Oued Beth in the Rharb Basin in northwestern Morocco has long been known to be exceptionally rich in fossils. The stratigraphic position ranging from the Late Miocene to the Pliocene has been controversial, however. In the course of my master’s degree field work in 1975/76, I mapped the right bank of the Oued Beth from Dar bel Hamri to El Kansera. Following multiple recent studies in the general region, I here review my results and present an updated comprehensive stratigraphic and geologic frame for the first time. The coquina near Dar bel Hamri is interpreted to be of Early Pliocene age, possibly containing some reworking of Late Miocene fossils. The coquina and other locations along the Oued Beth have yielded a rich otolith assemblage, which is described in this article. It represents the first fossil otolith-based fish fauna described from Northwest Africa and contains 96 species, 16 of which are new. The new species in the order of their description are Diaphus maghrebensis n. sp., Ophidion tuseti n. sp., Centroberyx vonderhochti n. sp., Myripristis ouarredi n. sp., Deltentosteus planus n. sp., Caranx rharbensis n. sp., Trachurus insectus n. sp., Parapristipoma bethensis n. sp., Pomadasys zemmourensis n. sp., Cepola lombartei n. sp., Trachinus maroccanus n. sp., Trachinus wernlii n. sp., Uranoscopus hoedemakersi n. sp., Uranoscopus vanhinsberghi n. sp., Spondyliosoma tingitana n. sp., and Opsodentex mordax n. sp. In addition, a new species is described from the Tortonian and Zanclean of Italy: Rhynchoconger carnevalei n. sp. Some additional otoliths are described from another Northwest Moroccan location of Early Pliocene age near Asilah, 50 km south of the Strait of Gibraltar. The Early Pliocene fish fauna from Dar bel Hamri in the Rharb Basin is also of interest, because it constitutes the nearest Atlantic fauna of the time of the reconnection of the Mediterranean with the Atlantic and may have acted as a hosting area for the remigration of fishes into the Mediterranean. Indeed, the correlation is high between the Northwest Moroccan and the well-known time-equivalent Mediterranean fish fauna, but the Moroccan fauna also contains a good proportion of putative endemic taxa and taxa with tropical West African affinities that apparently did not migrate into the Mediterranean. Thus, the Early Pliocene fish fauna from the Rharb Basin represents a unique assemblage for which I propose the biogeographic term “Maghrebian bioprovince.”

2023- Bratischko et al- Middle Miocene (Bessarabian) otoliths from Crimea, Estern Paratethys

Article

Full-text available

Feb 2023

Reconstructing fossil bony fish faunas using otoliths is a well-established method that allows a diverse and dense record in time and space to be assembled. Here, we report about a rich otolith-based fish fauna from the middle Sarmatian s.l. (middle Bessarabian) from Jurkine, Kerch Peninsula, Crimea. The study is based on more than 5,000 specimens constituting 36 different species, 24 of which are new and two remain in open nomenclature. This assemblage represents the first major otolith association described from the Bessarabian. It also represents a fish fauna from the last continuous restricted marine environment that evolved in the Eastern Paratethys, was recruited from the Badenian/Tarkhanian fauna, and was not affected by the subsequent Khersonian crisis. The association of otoliths is characterized by a high content of endemic fishes that derived from the relatively well-known early Sarmatian s.l. (Volhynian) fish fauna, and it contains certain faunal elements that were trapped in the then-isolated Eastern Paratethys and did not range into younger strata. This forced endemic evolution explains the unusually high percentage of new taxa. The fish fauna is dominated by stenohaline marine shelf fishes apparently recruited from the Konkian and earlier Sarmatian s.l. (Volhynian) fauna after the Karaganian crisis. The families Gobiidae and Gadidae benefited most in this restricted marine environment, while deep-water fishes disappeared with the Karaganian crisis. In this study, we discuss the further evolution of Eastern Paratethyan fishes as far as can be reconstructed from the relatively limited data from post-Bessarabian strata and also outline targets for future research in the field. The stratigraphic sequence of the Jurkine section is being revised based on a detailed suite of benthic foraminifera. Implications for the stratigraphy of the middle and upper Sarmatian s.l., their boundary, and the paleoenvironments of this part of the Kerch Peninsula are discussed.

Late Pliocene (Yorktown Formation) Teleostean Otoliths from New Localities in North Carolina, USA, and their Relationship to Other North American Assemblages

Article

Full-text available

Jan 2022

Abstract - Two new outcrops from the Late Pliocene Yorktown Formation in North Carolina, USA, at the Bell Bridge and Dixon localities produced 29 and 13 species, respectively, based on 672 teleostean otoliths. Otoliths are closely related to extant species along the present-day eastern U.S. coast with ophidiids, paralichthyids, and haemulids most abundant. Percentage similarity analysis indicates that the localities are markedly different. Based on the fossil fish assemblage, the paleoenvironment is interpreted as marine, deep inner–middle shelf, normal salinity, and tropical–temperate. The new Pliocene fish otolith assemblages were analyzed to understand the relationship to the coeval Yorktown Formation fish assemblage from the Lee Creek Mine. The new assemblages are significant, considering the limited number of North American Pliocene otolith studies and provide insight into northwestern Atlantic Coast Pliocene paleoenvironments. The relationship of the new Pliocene fish otoliths to known Pliocene otolith assemblages from North America is established.

First Cretaceous teleostean otolith assemblage (Arkadelphia Formation, upper Maastrichtian) from Arkansas, USA, early Gadiformes, and the Western Interior Seaway

Article

Full-text available

May 2023

The fortuitous discovery of Cretaceous (late Maastrichtian) teleostean otoliths in boring samples (17–31 m below ground level) from the Arkadelphia Formation near Cabot, Arkansas, USA, has consequential and overarching ramifications. The otolith assemblage, which is relatively large with 2,109 specimens, represents the first Mesozoic otolith assemblage described from Arkansas and one of the largest Cretaceous assemblages from a single USA site. The diversity of the assemblage is fairly large with a richness of 19 species with three additional taxa in open nomenclature and one unknown lapillus, which more than doubles the known actinopterygians from the Arkadelphia Formation. The otolith assemblage is extremely uneven in its diversity with one species, a putative siluriform Vorhisia vulpes Frizzell (1965b), accounting for approximately 73% of the total. The most unique feature of the otolith assemblage is the presence of cool-water gadiforms, which represent approximately 7.6% of the total assemblage. The presence of the gadiforms is related to the effects of the Western Interior Seaway and paleogeography during the Late Cretaceous in the western Gulf Coastal Plain. The gadiforms may represent relicts of a greater population and distribution in the early Maastrichtian. Percentage similarity measurements of the otolith assemblage indicate that the Arkadelphia Formation is more closely related to the Severn Formation in eastern Maryland (57.86%) and the Kemp Clay Formation in northeast Texas (35.77%) than to the Ripley Formation in northeastern Mississippi (5.34%). The similarity measurements and other factors indicate that the Arkadelphia Formation otolith assemblage belongs to the Western Interior Seaway community (bioprovince). The Arkadelphia Formation otolith assemblage also contains several taxa that become extinct, such as the ubiquitous V. vulpes, at the K-Pg extinction event. The otoliths point to a very shallow marine environment (possibly inner shelf; less than 20 m in depth) with estuarine and freshwater input nearby and may be utilized for refinement of paleoshorelines for the southern reaches of the Western Interior Seaway during the Late Cretaceous.

Middle and late Eocene fish otoliths from the eastern and southern USA

Article

Full-text available

Apr 2022

The fossil otoliths of the southern USA have been known for more than 130 years and are among the richest assemblages worldwide. However, previous studies are often scattered and employed outdated systematic scheme. A collection of over 25000 otoliths ranging in age from the Lutetian to the Priabonian from 47 sites in five states in the eastern and southern USA is analysed here. Combined with the earlier described material, at least 101 otolith-based taxa are documented, of which 83 are identified at species level. Fourteen of these are introduced as new species: Elopothrissus bernardlemorti sp. nov., “Muraenesox” barrytownensis sp. nov., Pseudophichthys texanus sp. nov., Paraconger wechesensis sp. nov., Neoopisthopterus weltoni sp. nov., “aff. Glyptophidium” stringeri sp. nov., Symmetrosulcus dockeryi sp. nov., Mene garviei sp. nov., “Citharus” varians sp. nov., Waitakia beelzebub sp. nov., Astroscopus compactus sp. nov., Parascombrops yanceyi sp. nov., Anisotremus rambo sp. nov., and Pagellus pamunkeyensis sp. nov. The assemblages are distinct from contemporary European faunas by the complete lack of mesopelagic fish otoliths, and by the presence of sciaenids. Dominant taxa in the American Eocene are the Ophidiidae, Sciaenidae, Lactariidae, and Congridae. They indicate shallow water environments for all the sampled sites. The notable abundance of those taxa suggests that they could have had a higher turnover rate, and provided fundamental nutrition in the local Paleogene marine ecosystem. Further analyses of the species in the stratigraphic succession revealed that a faunal turnover between the Claiborne and Jackson seas was evident in teleosts, and it might be more widespread in other marine organisms in the region.

Fish otolith record reveals possible tropical-subtropical fish community in temperate Japan during the exceptionally warm Last Interglacial period

Article

Full-text available

May 2023

Glacial-interglacial cycles are characteristic of the large-scale reorganisation of global climate during the Quaternary. Therefore, records of warmer-than-present periods, such as the Marine Isotope Stage (MIS) 5e, draw particular interest as they may aid scientists to predict how marine ecosystems may change in the future. However, fish fossil records during such warming periods are less clear. Here, we aim to reconstruct local fish fauna during the MIS 5e by describing fossil otoliths from two localities in central Japan belonging to the Otsu Sand and Mud Member of the Yokosuka Formation. A total of 544 otoliths were analysed, revealing the presence of at least 35 taxa. The fish assemblages reflect a mixture of coastal to oceanic epi-mesopelagic species. In addition, the remarkable occurrences of two present-day tropical species and its species composition demonstrate a possible complex tropical to subtropical-like fish fauna in the higher latitude Palaeo-Tokyo Bay during the warmer-than-present last interglacial period.

Addressing challenges in marine conservation with fish otoliths and their death assemblages

Article

Feb 2023

Otolith death assemblages provide a valuable source of biological and ecological information that can help address three main problems in marine conservation: a) the lack of pre-industrial, pre-human-impact baselines for evaluating change; b) the inefficiency of survey methods for recording small and cryptic fish species; and c) the absence of long-term data on environmental change impacts on marine ecosystems and fishes. We review here the current knowledge on the formation and preservation of otoliths and their death assemblages, and the methods to obtain, date and analyse them in order to detect changes in the species traits and ecology, the fish population structure and the palaeoceanographic shifts that drove them. Supplementary material at https://doi.org/10.6084/m9.figshare.c.6428742

Expliquer la biologie des espèces par leurs relations de parenté. Exemple des Scophthalmidae [Teleostéens : Pleuronectiformes].

Article

Full-text available

Jan 2008

RÉSUMÉ : Le présent travail a pour but d'essayer de comprendre l'origine de caractéristiques biologiques de poissons plats, famille des Scophthalmidae, au moyen d'un arbre de relations de parenté. La répartition de 12 caractéristiques a été analysée ; il est apparu que certaines n'étaient présentes que chez certaines espèces étroitement apparentées et pouvaient donc être expliquées en terme d'héritage depuis un ancêtre commun. En revanche, d'autres s'expliquent au moyen de convergences et d'adaptations récentes. Cependant, le manque de données biologiques pour certaines espèces empêche de proposer des scénarios pour expliquer l'origine de ces caractéristiques. ABSTRACT : Biology of species explained by interrelationships. Attempt on scophthalmid fishes [Pleuronectiformes]. The aim of this work is to try to interpret the Life-history traits of scophthalmid fishes with the results of the phylogenetic analysis proposed by Chanet (2003). 12 traits have been analysed: several, such as living on a rocky substrate or at important depth, are only present in some clades within the Scophthalmidae and thus can be interpreted as the result of inheritance and then appear to be synapomorphies. On the opposite, several cases of convergence and recent adaptation seem to have occurred for other traits. Unfortunately, the lack of biological data for some scophthalmid species prevents us from proposing any scenario explaining the origin of several Life-history traits. The importance of researching Life-history traits on various species for a better understanding of the origin of these traits is pointed out.

ResearchGate has not been able to resolve any references for this publication.

A comparative morphological treatise of recent and fossil otoliths of the order Pleuronectiformes

Recommended publications

A comparative morphological study of Recent otoliths of the Moridae (Gadiformes)

Comparative morphology of the sagittal otolith in three species of south Caspian gobies

Uptake of Fluorescent Gentamicin by Peripheral Vestibular Cells after Systemic Administration

Fossil lanternfish otoliths of California, with notes on fossil Myctophidae of North America