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35
The Nereididae (Annelida) – diagnoses, descriptions, and a key to
the genera
Robin S. Wilson1,2 , Christopher J. Glasby3,4 , Torkild Bakken5
1 Sciences Department, Museums Victoria Research Institute, Museums Victoria, GPO Box 666 Melbourne, Victoria 3001, Australia
2 The University of Melbourne, Melbourne, Victoria 3010, Australia
3 Museum and Art Gallery Northern Territory, PO Box 4646, Darwin NT 0801, Australia
4 Australian Museum Research Institute, Australian Museum, 1 William Street, Sydney, NSW 2010, Australia
5 Norwegian University of Science and Technology, NTNU University Museum, NO-7491 Trondheim, Norway
Corresponding author: Robin S. Wilson (rwilson@museum.vic.gov.au)
Copyright: © Robin S. Wilson et al.
This is an open access article distributed under
terms of the Creative Commons Attribution
License (Attribution 4.0 International –
CC BY 4.0).
Review Article
Abstract
Nereididae is among the most familiar of marine annelid families, common and well-stud-
ied in most marine environments but paradoxically no recent key or identication guide
exists to the world’s genera. Here updated generic descriptions, a list of characters, a
linear key to genera, and minimal diagnoses that distinguish each genus from all others
in the family are provided. This information is generated from a Delta database of 186
morphological characters and a link is provided to downloadable software allowing the
same data to be interrogated using the open-source Delta program Intkey – a nonlinear
multiple entry point computerised interactive key. For each genus the recent literature
is also summarised, comments on taxonomic status provided, and published keys to
species cited. Nexus format matrices are provided for all 45 genera and 158 Nereididae
species, representing all genera, scored for 146 multistate characters from the same
character list to facilitate future phylogenetic studies.
Key words: Computer taxonomy, diagnosis, identication tools, natural language
descriptions, polychaete, taxonomic verication, Taxonomic Information System
Academic editor: Greg Rouse
Received:
29 March 2023
Accepted:
31 July 2023
Published:
11 October 2023
ZooBank: https://zoobank.
org/76D0717B-0197-4A85-A30F-
A58338D1ED7B
Citation: Wilson RS, Glasby CJ,
Bakken T (2023) The Nereididae
(Annelida) – diagnoses, descriptions,
and a key to the genera. ZooKeys
1182: 35–134. https://doi.
org/10.3897/zookeys.1182.104258
ZooKeys 1182: 35–134 (2023)
DOI: 10.3897/zookeys.1182.104258
This article is part of:
Guides to Australian Annelida
36
ZooKeys 1182: 35–134 (2023), DOI: 10.3897/zookeys.1182.104258
Robin S. Wilson et al.: The Nereidid worms
Table of contents
Introduction ..........................................................................................................36
Methods ................................................................................................................37
Results and discussion ........................................................................................39
Annotated characters of Nereididae ..............................................................39
Prostomium, pharynx, and ventrum – characters 1–20 ...........................39
Pharyngeal papillae and paragnaths – characters 21–82 .......................45
Dorsal lamellae and parapodia – characters 83–128 ..............................52
Aciculae and chaetae – characters 129–178 ...........................................58
Pygidium and appendages – character 179 ..............................................65
Epitokal modications and reproduction – characters 180–186 ............67
Key to genera of Nereididae ............................................................................67
Systematic account of Nereididae genera .....................................................72
Acknowledgements ...........................................................................................125
Additional information .......................................................................................125
References ..........................................................................................................125
Supplementary material 1 .................................................................................134
Supplementary material 2 .................................................................................134
Introduction
The Nereididae is probably the best-known of all the families of marine an-
nelids (“polychaetes”) – the family includes many species that are commonly
encountered world-wide, intertidally, and also in diverse habitats from ephem-
eral freshwaters to abyssal depths (Bakken et al. 2022; Rouse et al. 2022).
Nereididae are also frequent study subjects in teaching laboratories, and some
species are commonly studied as laboratory animals (Fischer et al. 2010) (al-
though now known to comprise complexes of multiple species; see System-
atic account of Nereididae genera). Nereididae are almost invariably used as
exemplars of marine Annelida in invertebrate zoology textbooks (Marshall and
Williams 1972; Ruppert et al. 1994; Rouse and Giribet 2016). Nereididae are
signicant ecologically especially in intertidal ats (Compton et al. 2013; Choi
et al. 2014) where they form signicant components to the diet of sh and
shorebirds (Iwamatsu et al. 2007; Alves et al. 2013; Duijns et al. 2013) and are
aquaculture species of importance for sh bait and for aquaculture species
for human consumption (Yoshida 1984; Olive 1994; Lim et al. 2021). A number
of nereidid species are accidental introductions, or their introduced status is
cryptic (Einfeldt et al. 2014; Villalobos-Guerrero and Carrera-Parra 2015; Tosuji
et al. 2019; Kurt et al. 2021).
Taxonomic research on Nereididae is active, with nearly 100 papers published
in the past decade, and the family currently comprises 45 genera and 719 spe-
cies (Read and Fauchald 2023). Prominent among recent studies are investiga-
tions using molecular evidence leading to discovery of cryptic species (Glasby
et al. 2013; Villalobos-Guerrero and Bakken 2018; Tosuji et al. 2019; Teixeira et
al. 2022a, 2022b) and new phylogenetic hypotheses (Tosuji et al. 2018; Alves
et al. 2020, 2023; Villalobos-Guerrero et al. 2022b). The past decade has also
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Robin S. Wilson et al.: The Nereidid worms
seen description of 40 new species, revision of eight genera and a review of the
diversity, biology, anatomy, and ecology of the family Bakken et al. (2022).
Despite this recent taxonomic progress, identication of nereidid specimens
remains a challenge, especially to non-specialists. Genus-level identication is
dicult because no key to genera has been published since Fauchald (1977)
and our own interactive key, now 20 years out of date (Wilson et al. 2003).
Identication diculties are compounded by the wide recognition that several
of the most species-rich genera are assemblages of unrelated species (Bakken
and Wilson 2005; Bakken et al. 2022; Rouse et al. 2022). It is clear that a num-
ber of genera will be revised when further molecular systematic studies are
completed. But it is also clear that achieving sucient taxon sampling in those
molecular studies is a signicant challenge and that the composition of many
genera and identity of many species is likely to remain doubtful for a signicant
number of years. Yet the need for identication tools is widespread, not least
by those conducting new molecular systematics studies to resolve problematic
taxa. For these reasons we provide this review with the following aims:
• to provide updated descriptions of all genera; these correct one error in
Bakken et al. (2022) and also include additional characters (see System-
atic account of genera);
• to provide a dichotomous key to genera (see Key to genera of Nereididae)
and a downloadable interactive identication tool (= Taxonomic Informa-
tion System) using the Delta Intkey software (Wilson et al. 2023);
• to discriminate all genera based on minimal diagnoses (see Systematic
account of genera);
• to provide a character list (see Nereididae characters) and Nexus format
data matrices (Wilson et al. 2023) for inclusion in future phylogenetic
studies requiring morphological evidence.
Methods
We used the Delta (Descriptive Language for Taxonomy) suite of programs to
create and manage taxonomic data to support objective and quantitative de-
scription and discrimination of Nereididae taxa (Dallwitz 1974, 1980; Dallwitz
et al. 1993; Dallwitz and Paine 2015). The original implementation of the Del-
ta software by Australia’s Commonwealth Scientic and Industrial Research
Organisation (CSIRO) is still available as Windows only software via Dallwitz
(2020). The Delta software was ported to Java by the Atlas of Living Australia
as Open-Delta (Atlas of Living Australia 2014) as Windows/Mac OS/Linux soft-
ware and this is the version we use. A third implementation of Delta, although
lacking interactive identication software, is Cavalcanti (2022). The implemen-
tation of Delta is approximately identical in Dallwitz (2020) and Atlas of Living
Australia (2014) so the guide of Coleman et al. (2010), although based on Win-
dows software, is a very useful introduction for any Delta installation.
Delta comprises several separate applications: the Delta Editor manages
taxon by character data and generates outputs via scripts (called Action Sets).
For the purposes of this paper, principal outputs are natural language descrip-
tions and diagnoses of taxa (see below and Systematic account of Nereididae
genera), linear keys (see below and Key to genera of Nereididae), interactive
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Robin S. Wilson et al.: The Nereidid worms
keys and Nexus les (Wilson et al. 2023) and annotated character lists (see
Nereididae characters, below).
For each genus we include two Delta outputs: a description and a diagnosis
– terms that have been used loosely in much of the taxonomic literature, where
typically “diagnoses” are merely descriptions. Our descriptions are Delta-gen-
erated natural language outputs, use all character states known for a genus
based on the sources we list as interpreted against our character list. These are
concatenations of character states recorded for each taxon.
We concur with Borkent (2021) that diagnoses should be minimal statements
that precisely distinguish taxa – typically from other taxa of the same rank – and
ours do so. Borkent (2021) did not identify tools for the non-trivial task of gen-
erating such diagnoses but the Delta system has that capability: the DiagLevel
setting species the minimum number of characters for which the diagnostic
description should differ from all the other taxa (Dallwitz 1989). The diagnoses
provided below include, for all genera, ‘minimal diagnoses’ which as the name
implies, are a list of those characters which alone are sucient to distinguish the
given genus from all others. These minimal diagnoses were generated using the
Intkey setting DiagLevel=1. For many genera, the setting could be increased to
DiagLevel=2, thus generating additional characters which, for those genera, can
be used to verify a ‘minimal diagnosis’ that may have been tentatively achieved by
the user (perhaps when viewing damaged specimens, or when interpreting some
characters was uncertain). These additional diagnostic characters providing an
additional secondary level of verication are termed ‘secondary diagnosis’ in the
generic accounts below. Our intended use of the diagnosis is to verify identica-
tions by detecting errors that may have been made while using a key (Borkent
2021; also see comment below at the beginning of Key to genera of Nereididae).
The key was generated by the Delta Confor program with the following set-
tings: RBASE = 2.00 ABASE = 1.00 REUSE = 1.01 VARYWT = 0.80; Number of
conrmatory characters = 2. Following the recommendation of Dallwitz and
Paine (2015) these settings were arrived at by iterative modication: balancing
length of key (RBASE), evenness of subdivisions based on abundance indices,
(ABASE, not used here), minimising re-use of characters (REUSE) and treat-
ment of variable characters (VARYWT); Dallwitz (1974) provides further details.
Characters and character states are described and illustrated in the follow-
ing section. The downloadable Intkey interactive key associated with this paper
includes a more comprehensive set of character state illustrations. Two Nexus
les are provided as Suppl. materials 1, 2 and as part of Wilson et al. (2023).
One Nexus le contains all 45 genera, the second contains 158 species repre-
senting all nereidid genera (these are the 158 species for which we have the
most complete data). Delta truncates character and character state labels in
Nexus outputs to 30 characters; these truncated labels were replaced with full
names from original Delta text les using shell scripts provided by Buz Wilson
(pers. comm. 2 September 2023) and subsequent manual editing. Both Nexus
les use the same 146 unordered multistate characters; both exclude meris-
tic characters since their coding for phylogenetic analyses requires additional
data and assumptions (e.g., Lawing et al. 2008) and was beyond the scope of
this project. All these information sources are generated from the same Delta
database that was used for the diagnoses and descriptions.
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ZooKeys 1182: 35–134 (2023), DOI: 10.3897/zookeys.1182.104258
Robin S. Wilson et al.: The Nereidid worms
Interactive keys are implemented in the Delta suite by the Intkey application
(Dallwitz et al. 1995; Coleman et al. 2010) which requires binary les gener-
ated from the Delta Editor (Penev et al. 2009). Our Intkey les for Nereididae
are available as a separate download (Wilson et al. 2023) and require prior in-
stallation of the (recommended) Open-Delta software (Atlas of Living Australia
2014) or the original Delta programs (Dallwitz 2020). This paper serves as an
alternative for those unable to install the Delta software.
Results and discussion
Annotated characters of Nereididae
We identied 186 morphological characters to characterise nereidid taxa. Char-
acters are given as they are described in the Delta Editor with annotations and
illustrations as required, elaborating features in more detail. We have illustrated
characters that we consider the most useful for identication using specimens
lodged with the Museum & Art Gallery of the Northern Territory (NTM) and Mu-
seum Victoria (NMV), or derived from the literature as credited in the gure
captions. Some characters are included even though their potential to inform
higher level relationships are not yet tested, for example: palpophore surface
(character 4), and prostomium longitudinal groove (character 9). We have also
included some characters useful for distinguishing species (principally counts
of papillae and paragnaths on the eversible pharynx). Meristic characters, in
particular paragnath counts, are thus far rarely used to characterise nereidid
genera – typically such characters require data from large numbers of speci-
mens if they are to be the basis of robust taxonomic conclusions (Wilson 1993;
Wilson and Glasby 1993).
This character list is also the basis of the Nexus format les provided by Wil-
son et al. (2023). That Nexus le excludes meristic characters for the reasons
set out above, thus the 186 characters listed below are reduced to 146 multi-
state characters in Nexus outputs. Nexus le labels of character descriptions
in some are abbreviated for convenience in phylogenetic software; all Nexus
character labels are provided below in square brackets.
Prostomium, pharynx, and ventrum – characters 1–20 (Fig. 1A–P)
1. Antennae [NEXUS: antennae]
1. present.
2. absent.
All Nereididae have a pair of antennae excepting Unanereis Day, 1962 in
which a single antenna is present as illustrated in Day (1962: fig. 3a) (Una-
nereis macgregori) and Ben Amor (1980: fig. A) (Unanereis zghali). Bakken
et al. (2022) discussed the possibility that presence of a single antenna
is a developmental anomaly seen occasionally in Nereididae specimens,
in which case both species of Unanereis may be referable to Ceratonereis
orSolomononereis.
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Robin S. Wilson et al.: The Nereidid worms
Figure 1. Prostomium, pharynx A barrel-shaped palps (orange dashed outline) and palpophore surface with a single
transverse groove (open arrow) Namalycastis abiuma LNG M16Q3 B subconical palps (orange dashed outline) and pal-
pophore surface with several oblique grooves (lled arrows) Neanthes glandicincta MD165 anterior C caecal glands
(lled arrows) in ventral dissection of Perinereis vallata NMV F108784 D spherical palpostyles (lled arrow) and pros-
tomium with longitudinal groove (open arrow) Namalycastis abiuma E acutely conical palpostyles (lled arrow) and
indented prostomium (open arrow) Gymnonereis minyami F prostomium anterior margin entire Nereis sp. G prostomium
anterior margin indented (open arrow) Ceratonereis sp. H dentate jaws (lled arrow) Platynereis bicanaliculata NTM
W17252 I smooth/crenulate jaws (white arrow) Leonnates crinitus NTM W3330 J everted pharynx a truncate cone with
greatest width at margin of tentacular belt (= “frustrum-shaped”) Alitta sp. NMV F94547 K everted pharynx cylindrical
Simplisetia aequisetis NMV F94248 L ventral peristomial ap (lled arrows) and palpostyles subconical to oval-shaped
(open arrow) Cheilonereis peristomialis M ventrum of anterior chaetigers with rows of tubercles extending to the base
of each neuropodium (lled arrows) Australonereis ehlersi N ventrum of anterior chaetigers smooth Neanthes sp. NMV
F182608 O dorsal view pharynx with numbering following Kinberg Perinereis vallata P ventral view pharynx with number-
ing following Kinberg Perinereis vallata. Sources: A, B, F, H, I, M C. Glasby photographs C, J, K, N R. Wilson photographs
D modied after C. Glasby (1999) E modied after Hutchings and Reid (1990) G Leon Altoff photograph L, O, P R. Wilson
drawings. Not to scale; body widths of these example specimens are in the range 2–5 mm wide excluding parapodia.
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Robin S. Wilson et al.: The Nereidid worms
2. Palps [NEXUS: palp orientation]
1. anteriorly directed.
2. ventrally directed.
In most nereidids the palps are anteriorly directed and both palpophore and
palpostyles are typically easily seen in dorsal view e.g., Villalobos-Guerrero et
al. (2022b: g. 5b, c) for Nereis agulhana. However, in some taxa, e.g., Microne-
reis and some Kainonereis and Platynereis species, the palps are distinctly ven-
trally directed and not fully visible in dorsal view. Examples of ventrally directed
palps are Paxton (1983: g. 15) for Micronereis bansei, Conde-Vela et al. (2018:
g. 3b, c) for Kainonereis alata and Read (2007: g. 6a, b) for Platynereis aus-
tralis. Caution is required utilising this character alone for identication since,
at least in Kainonereis and Platynereis, this condition seems to be expressed in
epitokes and not always conrmed for atokes. Furthermore, it is plausible that
palps which may have been ventrally directed in live epitokes may be distorted
into an anteriorly directed palps orientation as an artefact caused by preserva-
tion with pharynx extended (Read 2007: gs 2a, 3a); Read (2007) did not make
use of this character to separate New Zealand species of Platynereis.
3. Palpophore [NEXUS: palpophore form]
1. barrel-shaped, approximately equal width from base to palpostyle (not
overly large compared with palpostyle; Fig. 1A).
2. massive subconical, attened palpostyle (minute by comparison; Fig. 1B).
Although palpophore shape has been considered in recent revisionary works
at the generic and species group levels, there has been no convincing argu-
ments identifying particular shapes. At least four characteristic shapes have
been documented: oval (Perinereis species complex) sub-ovoid (Composetia,
Leonnates), obtusely conical (Leonnates, Parasetia, Potamonereis), and sub-
conical (Parasetia, Neanthes) (Villalobos-Guerrero 2019; Villalobos-Guerrero et
al. 2021, 2022a, b). However, some genera were found to be polymorphic for
the states recognised and the states themselves can be dicult to distinguish,
especially if specimens are preserved in a distorted condition. Other authors
have distinguished palpophores on the basis of size: e.g., the palpophores of
Potamonereis have been referred to as massive (as in Potamonereis kumense-
nis (Sato, 2020)). The present 2-state system is an attempt to describe more
effectively the variation in the family. Thus, barrel-shaped palpophores (most
genera) have an approximately equal width from base to palpostyle. They are
not overly large compared to the size of the palpostyle, and in some cases
may be of similar length and usually they have a transverse groove (Fig. 1A).
Variability in length of barrel-shaped palpophores may be an indication that
this character needs to be further divided into additional states. Subconical,
dorso-ventrally attened palpophores (Alitta, Hediste, Leonnates, Neanthes mi-
cromma, Neanthes glandicincta; Fig. 1B) tend to be massive compared to the
size of the palpostyle, have a maximum width at mid to mid-end of palp, and
usually have longitudinal striae. Neanthes is polymorphic for this character and
Dendronereis is uncertain.
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Robin S. Wilson et al.: The Nereidid worms
4. Palpophore surface [NEXUS: palpophore surface]
1. without grooves or striae (palps short, compact; Fig. 1D).
2. with a single transverse groove (palpophores well developed (Fig. 1A).
3. with several oblique grooves or striae (palpophores well developed; Fig. 1B).
The presence of a transverse groove (Fig. 1A, open arrow) or multiple stri-
ae (Fig. 1B, lled arrows) on the palpophore, as noted by Villalobos-Guerrero
and Idris (2021) is present in many nereid genera with biarticulated palps. The
depth of the groove is variable depending on how extended the palps were on
xation. Sometimes many ner transverse grooves (striae) are visible although
they may be faint if the palps are extended. In general, we observed that bar-
rel-shaped forms have a single transverse groove which is perpendicular to the
long axis of the palpophore, and that subconical, attened forms possess mul-
tiple striae which are at an oblique angle.
5. Palpostyles [NEXUS: palpostyles]
1. present.
2. absent (palps undivided, minute).
A biarticulate palp with a distinct distal palpostyle is present in all Nereididae
except members of the genus Micronereis which have an undivided roughly
spherical palp that is also ventrally located on the anterior prostomium; see
Paxton (1983: g. 15; Micronereis bansei).
6. Palpostyles for m [NEXUS: palpostyles form]
1. spherical.
2. subconical.
3. acutely conical.
Palpostyles (present in all genera except Micronereis) are recognised as
having three shapes: spherical, subconical (in most nereidids; could also be re-
ferred to as oval-shaped), and acutely conical. The palpostyles are spherical in
members of the Namanereidinae, as illustrated by Glasby (1999: g. 10a; Nama-
lycastis abiuma). Some members of the genera Ceratocephale and Gymnonereis
have palpostyles that are acutely conical e.g., Hutchings and Reid (1990: g. 6a;
Ceratocephale aureola), Hutchings and Reid (1990: g. 9a; Gymnonereis minya-
mi), Wilson and Glasby (1993: g. 8a; Perinereis caeruleis). This character is also
useful for species separation across several unrelated genera of Nereididae.
7. Eyes [NEXUS: eyes]
1. present (Fig. 1E).
2. absent (Fig. 1D).
Two pairs of eyes are present in most Nereididae but they are absent in
a number of species found at bathyal and abyssal depths and subterranean
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Robin S. Wilson et al.: The Nereidid worms
and cave-dwelling Namanereidinae. Examples of the former are illustrated
by Hartman and Fauchald (1971: pl. 4 g. a; Ceratocephale abyssorum, as
Pisionura abyssorum) and Hartmann-Schröder (1975: g. 22; Neanthes
bioculata).
8. Prostomium anterior margin [NEXUS: prostomium anterior margin]
1. entire (Fig. 1F).
2. indented (Fig. 1E, G, open arrows).
The prostomium in Nereididae is usually entire on the anterior margin e.g., in
Composetia marmorata (Glasby 2015: g. 1G, H) but in 13 genera there is a con-
spicuous indentation between the antennae, as illustrated by Hutchings and
Reid (1990: g. 10a; Gymnonereis yurieli), Glasby (1999: g. 12a; Namalycastis
borealis) and Glasby (2015: g. 1A–E; Ceratonereis spp.).
9. Prostomium longitudinal groove [NEXUS: prostomium longitudinal groove]
1. present (Fig. 1D open arrow).
2. absent (Fig. 1E, F).
10. Tentacular belt length [NEXUS: tentacular belt length]
1. equal to or less than length of chaetiger 1.
2. greater than length of chaetiger 1.
Terminology for characters 10 and 11 follows Villalobos-Guerrero et al.
(2022a) who as part of a revision of Composetia showed that the body part
referred to widely in the literature as “tentacular segment”, “achaetigerous seg-
ment” and “apodous segment” comprises two segments plus the peristomium.
While some genera are polymorphic for this character, others consistently have
one or the other state. A short tentacular belt (state 1) distinguishes Namaly-
castis and Namanereis from most other nereidids.
11. Tentacular belt [NEXUS: tentacular belt divided]
1. fused, separate segments not recognisable.
2. represented by two distinct segments each carrying a pair of tentacu-
lar cirri.
12. Tentacular cirri comprising [NEXUS: tentacular cirri number]
1. four pairs.
2. three pairs.
13. Tentacular cirrophores [NEXUS: tentacular cirrophores]
1. present.
2. absent (cirri undivided).
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14. Tentacular cirri extending to chaetiger (number)
Small variations in the length of these cirri on the tentacular belt is often not a
useful statistic, but may assist in recognising taxa which have very long tentac-
ular cirri (e.g., Ceratonereis spp. and Platynereis spp.). Generally the posterodor-
sal pair is the longest.
15. Ventral peristomial ap [NEXUS: ventral peristomial ap]
1. present (Fig. 1L, lled arrows).
2. absent.
16. Ventrum of anterior chaetigers [NEXUS: ventrum anterior chaetigers]
1. smooth (Fig. 1N).
2. with rows of tubercles extending to the base of each neuropodium (Fig. 1M).
17. Oesophageal caeca [NEXUS: oesophageal caeca]
1. present (Fig. 1C).
2. absent.
Oesophageal caeca (equivalent terms are caecal glands, oesophageal
pouches) are a pair of organs that are prominent and easily visible if present,
but only by dissection. The oesophageal caeca are located immediately pos-
terior to the muscular pharynx. at the start of the oesophagus. Their utility in
taxonomy was rst suggested by Savigny (1822) but Khlebovich (2001) was
the rst to use these structures in the taxonomy of Nereididae.
18. Jaws [NEXUS: jaw dentition]
1. with smooth or slightly crenulate cutting edge (Fig. 1I).
2. with dentate cutting edge (Fig. 1H).
Variation in jaw morphology is as yet not well understood. Some taxa have
jaws with smooth or faintly crenulate cutting edge, while others have distinctly
or indistinctly toothed jaws. In some taxa the jaws are robust and dark (e.g.,
Neanthes spp., Perinereis spp.), while others have ner, translucent jaws (e.g.,
Ceratocephale spp., some Simplisetia spp.). However, many taxa are interme-
diate between these conditions, and abrasion may falsely result in the appear-
ance of “smooth” jaws. Differences in the chemical composition of nereidid
jaws may offer the best opportunity to distinguish taxa, but these studies have
yet to be undertaken systematically.
19. Everted pharynx shape [NEXUS: everted pharynx form]
1. cylindrical (Fig. 1K).
2. a truncate cone, tapering, greatest width at margin of tentacular segment
(Fig. 1J).
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Robin S. Wilson et al.: The Nereidid worms
This character was introduced by Villalobos-Guerrero et al. (2021) using the
term “frustrum-shaped” however we prefer simpler language (and frustrum can
also refer to a truncate pyramid).
20. Maxillary ring of pharynx [NEXUS: maxillary ring of pharynx]
1. divided into discrete Areas (Fig. 1O, P).
2. undivided.
Pharyngeal papillae and paragnaths – characters 21–82 (Fig. 2A–G)
21. Maxillary ring of pharynx with papillae [NEXUS: maxillary ring papillae]
1. present.
2. absent.
22. Maxillary ring of pharynx with papillae [NEXUS: maxillary papillae arrangement]
1. solitary.
2. in tufts.
23. Maxillary ring of pharynx with papillae number
A count of the total number of papillae on the maxillary ring helps to discrimi-
nate taxa and is practical even when the arrangement in discrete Areas is un-
clear, as is often the case in Gymnonereidinae.
24. Undivided maxillary ring – total number of paragnaths present
Micronereis is the only nereidid genus with paragnaths present on an undivided
maxillary ring. In this genus the pharynx is not fully eversible and specimens
are small – the number of paragnaths present can only be recorded as a single
number, if it can be determined at all.
25. Maxillary ring paragnaths [NEXUS: maxillary ring paragnaths]
1. present.
2. absent.
26. Maxillary ring of pharynx with P-bar paragnaths (Fig. 2A) [NEXUS: maxillary
ring Pbars]
1. present, usually in regular comb-like rows.
2. absent.
27. Area I conical paragnaths (Fig. 2B) [NEXUS: Area I conical paragnaths]
1. present.
2. absent.
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28. Area I conical paragnaths: number
29. Area II conical paragnaths [NEXUS: Area II conical paragnaths]
1. present.
2. absent.
30. Area II conical paragnaths: number
31. Area II rod-like paragnaths (Fig. 2C) [NEXUS: Area II rodlike paragnaths]
1. present.
2. absent.
32. Area II rod-like paragnaths: number
33. Area III conical paragnaths [NEXUS: Area III conical paragnaths]
1. present.
2. absent.
34. Area III conical paragnaths: number
35. Area III conical paragnaths: isolated lateral groups [NEXUS: Area III lateral
groups]
1. present.
2. absent.
In many taxa Area III paragnaths include a few paragnaths positioned as
distinct groups on each side of the main group.
36. Area III rod-like paragnaths [NEXUS: Area III rodlike paragnaths]
1. present.
2. absent.
37. Area III rod-like paragnaths: number
38. Area IV paragnaths [NEXUS: Area IV paragnaths]
1. present.
2. absent.
39. Area IV conical paragnaths [NEXUS: Area IV conical paragnaths]
1. present.
2. absent.
40. Area IV conical paragnaths: number
41. Area IV smooth bar-like paragnaths (Fig. 2D) [NEXUS: Area IV smooth bars]
1. present.
2. absent.
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These are the smooth bar paragnaths of Bakken et al. (2009) and are not formed
by fusion of separate conical paragnaths but are apparently present throughout
development in the form of smooth bars in all those taxa in which they occur.
When they occur on Area IV, cones are also usually present (sometimes lacking,
see Tosuji et al. 2019), as illustrated in Hutchings et al. (1991: g. 3B; Perinereis
amblyodonta) and Villalobos-Guerrero et al. (2022b: g. 4B; Neanthes capensis).
Thus, bar-like paragnaths are distinct from “melted paragnaths” described
and illustrated by Bakken et al. (2009: g. 2c) which are formed by partial fusion
of distinct paragnaths and occur most often in epitokes and are not considered
to have taxonomic value. Glasby et al. (2011) claried that the term “melted”
should apply only to conical paragnaths mounted on a plate-like basement while
Conde-Vela and Salazar-Vallejo (2015) introduced the term “merged paragnaths”
for forms where a basement is not present. We have not used merged or melted
paragnaths here since their intra-specic variability is incompletely understood.
42. Area IV smooth bar-like paragnaths: number
Paragnaths on Area IV are typically roughly conical in shape, though variations
range from attened domes of irregular shape to tooth-like paragnaths. In
some taxa, particularly species of Neanthes and Perinereis, in addition to cones
a separate patch of bar-shaped paragnaths occurs at the maxillary end of Area
IV; these bars are counted separately.
43. Area IV rod-like paragnaths [NEXUS: Area IV rodlike paragnaths]
1. present.
2. absent.
44. Area IV rod-like paragnaths: number
45. Oral ring papillae [NEXUS: oral ring papillae]
1. present.
2. absent.
46. Oral ring papillae: number
47. Oral ring papillae arrangement [NEXUS: oral ring papillae arrangement]
1. solitary.
2. arranged in tufts.
48. Area V papillae [NEXUS: Area V papillae]
1. present.
2. absent.
49. Area V papillae: number
In Ceratocephale spp., Area V and VI contain up to three papillae in total; these
are here interpreted as all occurring in Area V, with VI = 0,0.
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50. Area VI papillae [NEXUS: Area VI papillae]
1. present.
2. absent.
51. Area VI papillae: number
52. Areas VII-VIII papillae [NEXUS: Areas VIIVIII papillae]
1. present.
2. absent.
53. Areas VII-VIII papillae: number
54. Areas VII-VIII papillae arranged [NEXUS: Areas VIIVIII papillae rows]
1. in a single row.
2. in a double row.
Where a double row of papillae is present, the 2nd (posterior) row may be hard
to see unless the pharynx is completely everted.
55. Oral ring paragnaths [NEXUS: oral ring paragnaths]
1. present.
2. absent.
56. Oral ring paragnaths (discrete or continuous) [NEXUS: oral ring paragnaths
arranged]
1. with Areas V, VI and VII-VIII discrete.
2. comprising a continuous ring dorsally and ventrally, discrete groups not
recognisable.
57. Oral ring paragnaths on Areas V and VI (discrete or continuous) [NEXUS:
Areas VVI paragnaths]
1. form discrete groups.
2. continuous, not recognisably distinct.
58. Oral ring pyramidal paragnaths (Fig. 2E) [NEXUS: oral ring pyramidal
paragnaths]
1. present.
2. absent.
Pyramidal paragnaths have a quadrangular base and taper to a pointed apex
(Bakken et al. 2009: 309).
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59. Crown-shaped oral ring paragnaths (Fig. 2F) [NEXUS: oral ring crown paragnaths]
1. present.
2. absent.
60. Crown-shaped oral ring paragnaths: number
61. Area V conical paragnaths [NEXUS: Area V conical paragnaths]
1. present.
2. absent.
62. Area V conical paragnaths: number
63. Area V conical paragnaths arranged [NEXUS: Area V cones arranged]
1. in a triangle.
2. in a longitudinal line.
3. irregularly.
64. Area VI paragnaths [NEXUS: Area VI paragnaths]
1. present.
2. absent.
65. Area VI paragnaths arranged [NEXUS: Area VI paragnaths arranged]
1. in a roughly circular group.
2. in lines or arcs.
Area VI paragnaths are usually arranged in a circular or irregular compact
group (sometimes of only one or two paragnaths). In some species of Nean-
thes, an alternative arrangement of cones occurs: a distinct line or arc.
66. Area VI conical paragnaths [NEXUS: Area VI conical paragnaths]
1. present.
2. absent.
67. Area VI conical paragnaths: number
68. Area VI smooth bars (Fig. 2D) [NEXUS: Area VI smooth bars]
1. present.
2. absent.
Tosuji et al. (2019) demonstrated that in some species of Perinereis, long
smooth bars in Area VI may shorten in length with growth of the worm to the
extent that Area VI paragnaths in mature forms show a mixture of short bars
and cones, so care must be exercised in using this character.
69. Area VI smooth bars: number
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70. Area VI shield-shaped bars (Fig. 2G) [NEXUS: Area VI shield-shaped bars]
1. present.
2. absent.
Shield-shaped bars are laterally compressed and have a pointed or rounded
apex (Bakken et al. 2009: 311).
71. Area VI shield-shaped bars: number
72. Area VI rod-shaped paragnaths [NEXUS: Area VI rod paragnaths]
1. present.
2. absent.
73. Area VI rod-shaped paragnaths: number of rows
74. Areas VII-VIII paragnaths [NEXUS: Areas VIIVIII paragnaths]
1. present.
2. absent.
75. Areas VII-VIII conical paragnaths [NEXUS: Areas VIIVIII cone paragnaths]
1. present.
2. absent.
76. Areas VII-VIII conical paragnaths: number
Areas VII-VIII typically forms a continuous ventro-lateral band of paragnaths
and is recorded as such. In a few taxa the Areas VII-VIII band of paragnaths is
extended through the dorsal region and encircles the oral ring of the pharynx;
in this case even though the band nominally extends through the dorsal Areas
V and VI, they are indistinguishable and the count is recorded for Areas VII-VIII.
77. Areas VII-VIII conical paragnaths arranged [NEXUS: Areas VIIVIII cones ar-
ranged]
1. in isolated patches.
2. in one or more irregular lines forming a continuous band.
In a few nereidid species, e.g., Cheilonereis peristomialis Benham, 1916, the
paragnaths on Areas VII-VIII are arranged in distinct isolated patches. In other
nereidids the arrangement is an irregular but continuous band made up one or
more rows deep.
78. Areas VII-VIII conical paragnaths (size distribution) [NEXUS: Areas VIIVIII
cones sizes]
1. similar in size, or irregular mix of large and small paragnaths in a single band.
2. differentiated, with a separate band of minute paragnaths also present.
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Figure 2. Paragnaths A P-bar paragnaths Pseudonereis anomala B conical paragnaths Pseudonereis trimaculata C rod-like
paragnaths Platynereis polyscalma D smooth bar paragnaths Perinereis vancaurica E pyramidal paragnaths Perinereis akuna
F crown paragnaths Micronereis piccola G shield-shaped paragnaths Pseudonereis trimaculata. Sources: A–E, G emended
from Bakken et al. (2009: gs 2–5) F emended from Paxton (1983: g. 4). Scale bars: 0.1 mm (A–E, G); 200 μm (F).
Typically the paragnaths on Areas VII-VIII comprise a variety of sizes irreg-
ularly arranged. However, in some taxa there is differentiation into an anterior
band of paragnaths similar in size to elsewhere on the proboscis, and a sepa-
rate band of minute paragnaths.
79. Areas VII-VIII P-bar paragnaths (Fig. 2A) [NEXUS: Areas VIIVIII Pbars]
1. present.
2. absent.
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80. Areas VII-VIII P-bar paragnaths (interspersed/discrete) [NEXUS: Areas
VIIVIII Pbar arrangement]
1. interspersed with conical paragnaths.
2. forming a separate band.
81. Areas VII-VIII rod-shaped paragnaths (Fig. 2C) [NEXUS: Areas VIIVIII rod
paragnaths]
1. present.
2. absent.
82. Areas VII-VIII rod-shaped paragnaths: number of rows
Dorsal lamellae and parapodia – characters 83–128 (Fig. 3A–G)
83. Transverse dorsal lamellae (Fig. 3A) [NEXUS: transverse dorsal lamellae]
1. present.
2. absent.
84. Transverse dorsal lamellae, commencing chaetiger
85. Transverse dorsal lamellae, last present chaetiger
86. Transverse dorsal lamellae, mid-dorsal papilla [NEXUS: middorsal papilla]
1. present.
2. absent.
It has been shown by Blake (1985) and Hilbig (1997) (for Ceratocephale
loveni) and by Hylleberg and Nateewathana (1988) (for Ceratocephale an-
daman) that presence/absence of mid-dorsal papilla is variable and likely
to be related to size or sexual maturity. However, the description of Cera-
tocephale papillata de León-González & Góngora-Garza, 1992 is based on
155 specimens, all of which have mid-dorsal papilla. In other species of
Ceratocephale, observations on mid-dorsal papillae should be interpreted
with caution.
87. Transverse dorsal lamellae mid-dorsal papilla commencing chaetiger
88. Notopodium [NEXUS: notopodium development]
1. with at least one distinct ligule or lobe.
2. strongly reduced, without distinct lobes or ligules.
According to nautical wisdom, boats are dened as vessels able to be car-
ried on ships. Parapodial lobes and ligules are distinguished according to a
similar logic: lobes can be carried on ligules, but not vice versa. In general,
ligules are larger and atter than the smaller, conical lobes.
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89. Dorsal notopodial ligule (Fig. 3E) [NEXUS: dorsal notopodial ligule]
1. present.
2. absent.
90. Dorsal notopodial ligule, rst present [NEXUS: dorsal notopodial ligule rst]
1. chaetiger 1.
2. chaetiger 3.
3. chaetiger 4.
4. chaetiger 5.
91. Dorsal notopodial ligule, length on anterior chaetigers [NEXUS: dorsal no-
topodial ligule anterior]
1. markedly elongate.
2. not markedly elongate.
3. markedly reduced.
92. Dorsal notopodial ligule, length on posterior chaetigers [NEXUS: dorsal no-
topodial ligule posterior]
1. markedly elongate (Fig. 3D).
2. not markedly elongate.
93. Dorsal notopodial ligule, breadth on posterior chaetigers [NEXUS: dorsal
notopodial ligule posterior width]
1. markedly broader (Fig. 3G).
2. not markedly broader.
94. Dorsal notopodial ligule, reduction on posterior chaetigers [NEXUS: dorsal
notopodial ligule posterior size]
1. absent (Fig. 3B).
2. markedly reduced.
3. not markedly reduced (Fig. 3F).
95. Dorsal notopodial ligule (divided into branchiae or not) [NEXUS: dorsal no-
topodial branchiae]
1. divided into numerous branchial laments (Fig. 3H).
2. not divided into numerous branchial laments.
Only in Dendronereides is the dorsal notopodial ligule divided into numerous
branchial laments. The branchial structures of Dendronereides and Dendrone-
reis are therefore not homologous.
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96. Prechaetal notopodial lobe (Fig. 3B, F) [NEXUS: prechaetal notopodial lobe]
1. present.
2. absent.
The prechaetal notopodial lobe is here dened as a digitiform process that is
anterior to the acicular notopodial lobe and is not supported by the notopodial
acicula (see character 100 Notopodial acicular process).
97. Prechaetal notopodial lobe, development [NEXUS: prechaetal notopodial
lobe size]
1. smaller than dorsal notopodial ligule on anterior chaetigers, usually re-
duced or absent posteriorly.
2. approximately equal to length of dorsal notopodial ligule at least on an-
terior chaetigers (thus notopodium of three similar sized ligules/lobes).
98. Prechaetal notopodial lobe distribution [NEXUS: prechaetal noto lobe location]
1. present on all chaetigers (may be reduced in size on posterior chaetigers).
2. restricted to a limited number of anterior chaetigers.
99. Prechaetal notopodial lobe, reducing in size posteriorly, last present at ap-
prox. chaetiger
100. Notopodial acicular process (Fig. 3E open arrow) [NEXUS: notopodial acic-
ular process]
1. present.
2. absent.
The notopodial acicular process, if present, is a small digitiform process
formed around the tip of the acicula and is located between the acicular
and ventral notopodial ligules (see character 97 Prechaetal notopodial
lobedevelopment).
101. Notopodial acicular process reducing in size posteriorly, last present on
chaetiger
102. Notopodial acicular ligule (Fig. 3E–G) [NEXUS: acicular notopodial ligule]
1. present.
2. absent.
The acicular notopodial ligule is here considered to be that eshy ligule ven-
tral to the acicula in the notopodium. It is present in Nereidinae, but absent
in Ceratocephale, Gymnonereis, Micronereis and Stenoninereis. Males of some
species of Micronereis have a process on the ventral side of the notopodial
acicular lobe; this dimorphic character is here considered not homologous with
the ventral notopodial ligule of most nereidids.
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103. Acicular notopodial ligule development [NEXUS: acicular notopodial ligule
form]
1. similar to or shorter than neuropodial acicular ligule.
2. prolonged, distinctly longer than neuropodial acicular ligule.
3. reduced, much shorter than neuropodial acicular ligule.
104. Dorsal cirrus (divided into branchiae or not) [NEXUS: dorsal cirrus branchiae]
1. divided into numerous branchial laments (Fig. 3I).
2. not divided into numerous branchial laments.
Figure 3. Parapodia A transverse dorsal lamellae (lled arrows) Ceratocephale setosa B attened post-chaetal neuropodial
lobe (lled arrow), accessory ventral cirrus (open arrow) anterior parapodium anterior view Ceratocephale setosa C cirro-
phore of dorsal cirrus enlarged and vascularised (lled arrow), acicular notopodial ligule present (open arrow) posterior
parapodium anterior view Ceratocephale setosa D dorsal notopodial ligule (= accessory dorsal cirrus of some authors)
(lled arrow) ventral neuropodial ligule (open arrow) Gymnonereis minyami chaetiger 34 anterior view E notopodial acicular
process (open arrow) digitiform neuropodial postchaetal lobe (lled arrow) Neanthes tasmani chaetiger 30 anterior view
(ventral cirrus missing) F notopodial prechaetal lobe (open arrow) digitiform neuropodial postchaetal lobe (lled arrow)
Neanthes tasmani chaetiger 30 anterior view G dorsal notopodial ligule markedly broader on posterior chaetigers (lled
arrow) chaetiger 78 Alitta succinea USNM 27799 H dorsal notopodial ligule divided into branchiae (lled arrow) dorsal cirrus
(open arrow) Dendronereides heteropoda chaetiger 19 anterior view I dorsal cirrus divided into branchial laments (lled ar-
row) Dendronereis sp chaetiger 14 anterior view. Sources: A–D Hutchings and Reid (1990) E,F modied after Bakken (2002)
G R. Wilson drawing H, I C. Glasby photographs. Abbreviations: anl, acicular notopodial ligule; dc, dorsal cirrus; dnl, dorsal
notopodial ligule; pnl, prechaetal notopodial ligule; vnl, ventral neuropodial ligule; vc, ventral cirrus. Not to scale; maximum
body width excluding parapodia of 3A specimen ~ 1.2 mm; for remaining gures acicula lengths in the range 0.1–0.4 mm.
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Only in Dendronereis does the dorsal cirrus form numerous branchial la-
ments. The branchial structures of Dendronereides and Dendronereis are there-
fore not homologous.
105. Dorsal cirrus (Fig. 3B, F) length on chaetiger 10–20 relative to length of
acicular notopodial ligule
106. Dorsal cirrus: sub-terminally attached to dorsal notopodial ligule on poste-
rior chaetigers, or not [NEXUS: dorsal cirrus subterminal]
1. sub-terminally attached to dorsal margin of dorsal notopodial ligule on
posterior chaetigers (Fig. 3G).
2. not sub-terminally attached to dorsal notopodial ligule on posterior chaetigers.
107. Dorsal cirrus terminally attached to dorsal notopodial ligule on posterior
chaetigers, or not [NEXUS: dorsal cirrus terminal]
1. terminally attached to dorsal notopodial ligule on posterior chaetigers.
2. not terminally attached to dorsal notopodial ligule on posterior chaetigers.
108. Dorsal cirrus terminally attached, or not [NEXUS: dorsal cirrus terminal all]
1. terminally attached throughout, so that dorsal notopodial ligule has ap-
pearance of a cirrophore for the dorsal cirrus.
2. not terminally attached throughout all chaetigers.
109. Dorsal cirrus (with/without cirrophore) [NEXUS: dorsal cirrophore]
1. simple, lacking basal cirrophore (Fig. 3C, lled arrow).
2. arising from basal cirrophore.
110. Cirrophore of dorsal cirrus length [NEXUS: dorsal cirrophore development]
1. short, at most as long as ventral notopodial ligule.
2. much longer than ventral notopodial ligule (Fig. 3D).
111. Cirrophore of dorsal cirrus enlargement [NEXUS: dorsal cirrophore vascular]
1. enlarged and vascularised (Fig. 3C, lled arrow).
2. not enlarged and vascularised.
112. Cirrophore of dorsal cirrus (expanded and leaike, or cylindrical) [NEXUS:
dorsal cirrophore expanded]
1. expanded and leaike (Fig. 3C, lled arrow).
2. cylindrical throughout.
113. Cirrophore of dorsal cirrus expanded commencing approx. chaetiger
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114. Neuropodial prechaetal lobe [NEXUS: neuropodial prechaetal lobe]
1. present.
2. absent.
Terminology after Hylleberg and Nateewathana (1988); characteristically
present in the gymnonereids Ceratocephale and Gymnonereis. A structure of
the same name is described as being present in descriptions (mostly prior to
1988), for example in some species of Ceratonereis but we contend that these
are misinterpretations.
115. Neuropodial prechaetal lobe present on chaetigers
116. Neuropodial prechaetal lobe development [NEXUS: neuropodial prechae-
tal lobe form]
1. projecting beyond postchaetal lobe (at least in anterior chaetigers).
2. not projecting beyond the postchaetal lobe.
117. Neuropodial postchaetal lobe (Fig. 3E, lled arrow) [NEXUS: neuropodial
postchaetal lobe]
1. present.
2. absent.
118. Neuropodial postchaetal lobe [NEXUS: neuropodial postchaetal lobe length]
1. projecting beyond end of the acicular ligule (Fig. 3E, lled arrow).
2. not projecting beyond end of the acicular ligule.
119. Neuropodial postchaetal lobe distribution [NEXUS: neuropodial postchae-
tal lobe distribution]
1. present throughout all chaetigers.
2. restricted to anterior chaetigers.
120. Neuropodial postchaetal lobe form [NEXUS: neuropodial postchaetal
lobe form]
1. digitiform (Fig. 3E lled arrow).
2. attened.
121. Neuropodial postchaetal lobe reducing posteriorly, last present on chaetigers
122. Ventral neuropodial ligule of anterior chaetigers [NEXUS: ventral neuropo-
dial ligule anterior]
1. present (Fig. 3E).
2. absent.
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123. Ventral neuropodial ligule of anterior chaetigers development [NEXUS:
ventral neuropodial ligule anterior length]
1. approx. as long as acicular neuropodial ligule (Fig. 3E).
2. short, up to half length of acicular neuropodial ligule.
124. Ventral neuropodial ligule on posterior chaetigers [NEXUS: ventral neu-
ropodial ligule posterior]
1. present.
2. absent.
125. Ventral neuropodial ligule on posterior chaetigers development [NEXUS:
ventral neuropodial ligule posterior length]
1. similar to length of acicular neuropodial ligule.
2. longer than acicular neuropodial ligule.
3. short, up to half length of acicular neuropodial ligule (Fig. 3G).
126. Accessory ventral cirrus (Fig. 3B, open arrow) [NEXUS: accessory ventralcirrus]
1. present (i.e., double ventral cirri).
2. absent.
127. Accessory ventral cirrus commencing chaetiger
128. Relative length of paired ventral cirri [NEXUS: accessory ventral cirri length]
1. superior ventral cirrus of chaetigers 10–20 longer than inferior cirrus
(Fig.3B, D).
2. superior ventral cirrus of chaetigers 10–20 and inferior cirrus similar in
length (Fig. 3C).
3. superior ventral cirrus of chaetigers 10–20 shorter than inferior cirrus.
In most Ceratocephale the superior cirrus is always the longer of the pair,
especially on the rst few chaetigers. However, in at least one species, Cer-
atocephale papillata, the superior cirrus is shorter than the inferior cirrus on
anterior-most 10–20 chaetigers.
Aciculae and chaetae – characters 129–178 (Fig. 4A–Q)
129. Notoaciculae on chaetigers 1 and 2 [NEXUS: notoaciculae chaetigers 1 2]
1. present.
2. absent.
Presence of notoaciculae in chaetigers 1 and 2 is dicult to observe and
failure to mention this character in published descriptions cannot be taken as
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evidence of absence. It is necessary to manipulate the parapodia with trans-
mitted light, or, preferably in small specimens, to remove and mount parapodia
on slides. In Ceratonereis mirabilis and related species, notoaciculae of chae-
tigers 1 and 2 are present, but are short and translucent even though those
of subsequent chaetigers are dark and extend to the tip of the acicular ligule.
Namalycastis and Namanereis have notoacicula in chaetigers 1 and 2, although
like notoaciculae in remaining chaetigers, they sit just above the neuroaciculae
in the upper part of the neuropodium.
130. Notochaetae of chaetigers 3 and 4 [NEXUS: notochaetae chaetigers 3 4]
1. present.
2. absent.
131. Notochaetae: heterogomph spinigers [NEXUS: notochaetae heterogomph
spinigers]
1. present.
2. absent.
Chaetal shaft with heterogomph articulation is illustrated in Fig. 4B. Equiva-
lent to long-bossed heterogomph sensu Conde-Vela (2021); see character 133
Notochaetae: sesquigomph spinigers. The chaetal shaft boss is the structure
indicated with a lled arrow on Fig. 4B, C, L.
132. Notochaetae: homogomph spinigers [NEXUS: notochaetae homogomph
spinigers]
1. present.
2. absent.
Chaetal shaft with homogomph articulation is illustrated in Fig. 4A. Equiva-
lent to short-bossed heterogomph sensu Conde-Vela (2021).
133. Notochaetae: sesquigomph spinigers [NEXUS: notochaetae sesquigomph
spinigers]
1. present.
2. absent.
Chaetal shaft with sesquigomph articulation is illustrated in Fig. 4C. Despite
the advance in quantifying chaetal articulation by Conde-Vela (2021) we retain
the terms homogomph/ heterogomph/ sesquigomph due to their near-univer-
sal usage in the literature over the near-equivalents proposed by Conde-Vela
(2021). It would also be desirable to compare inter- and intra-specic variation
between veried Nereididae species before adopting new terms and a revised
assessment of their taxonomic signicance.
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134. Notochaetae: homogomph falcigers (Fig. 4K–Q) [NEXUS: notochaetae ho-
mogomph falcigers]
1. present.
2. absent.
135. Notochaetae: homogomph falcigers with terminal tendon (Fig. 4K, lled
arrow) [NEXUS: notochaetae homogomph falcigers tendon]
1. present.
2. absent.
136. Notochaetae: homogomph falcigers rst present at chaetiger
137. Notochaetae: homogomph falcigers articulation [NEXUS: notochaetae ho-
mogomph falcigers articulation]
1. fused on some chaetigers (present as a simple chaeta).
2. with blade free throughout.
138. Notochaetae: homogomph falcigers with smooth blade (Fig. 4M) [NEXUS:
notochaetae homogomph falcigers blade smooth]
1. present.
2. absent.
139. Notochaetae: homogomph falcigers with bidentate blade and large ad-
jacent terminal and subterminal teeth (Fig. 4N) [NEXUS: notochaetae ho-
mogomph falcigers bidentate]
1. present.
2. absent.
140. Notochaetae: homogomph falcigers with bidentate blade and large wide-
ly-separated terminal and subterminal teeth (Fig. 4O) [NEXUS: notochaetae ho-
mogomph falcigers bidentate gap]
1. present.
2. absent.
141. Notochaetae: homogomph falcigers with multidentate blade with ≥ 2 large
lateral teeth, rst lateral tooth subequal to terminal tooth, subsequent teeth
usually decreasing in size (Fig. 4P) [NEXUS: notochaetae homogomph fal-
cigers multidentate large]
1. present.
2. absent.
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142. Notochaetae: homogomph falcigers with multidentate blade with ≥ 2 small
lateral teeth, rst and subsequent lateral teeth much smaller than terminal tooth
(Fig. 4Q) [NEXUS: notochaetae homogomph falcigers multidentate small]
1. present.
2. absent.
143. Notochaetae: sesquigomph falcigers (Fig. 4L) [NEXUS: notochaetae ses-
quigomph falcigers]
1. present.
2. absent.
144. Notochaetae: sesquigomph falcigers from chaetiger
145. Notochaetae: sesquigomph falcigers blade form [NEXUS: notochaetae
sesquigomph falcigers bid]
1. distally bid (Fig. 4K, L open arrows).
2. with a single distal tooth/.
146. Neurochaetae dorsal fascicle: heterogomph spinigers [NEXUS: neuro-
chaetae dorsal fascicle heterogomph spinigers]
1. present.
2. absent.
147. Neurochaetae dorsal fascicle: homogomph spinigers [NEXUS: neurochae-
tae dorsal fascicle homogomph spinigers]
1. present.
2. absent.
148. Neurochaetae dorsal fascicle: sesquigomph spinigers [NEXUS: neuro-
chaetae dorsal fascicle sesquigomph spinigers]
1. present.
2. absent.
149. Neurochaetae dorsal fascicle: sesquigomph falcigers [NEXUS: neurochae-
tae dorsal fascicle sesquigomph falcigers]
1. present.
2. absent.
150. Neurochaetae dorsal fascicle: sesquigomph falcigers blades [NEXUS:
neurochaetae dorsal fascicle sesquigomph falcigers smooth]
1. serrated.
2. smooth.
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151. Neurochaetae dorsal fascicle: heterogomph falcigers in anterior chaeti-
gers [NEXUS: neurochaetae dorsal fascicle heterogomph falcigers anterior]
1. present.
2. absent.
152. Neurochaetae dorsal fascicle: heterogomph falcigers on posterior chae-
tigers [NEXUS: neurochaetae dorsal fascicle heterogomph falcigers posterior]
1. present.
2. absent.
153. Neurochaetae dorsal fascicle: heterogomph falcigers blades [NEXUS: neu-
rochaetae dorsal fascicle heterogomph falcigers smooth]
1. smooth/
2. serrated/
154. Neurochaetae dorsal fascicle: heterogomph falcigers blades with teeth
[NEXUS: neurochaetae dorsal fascicle heterogomph falcigers teeth]
1. only slightly longer proximally than distally.
2. much longer proximally than distally.
155. Neurochaetae dorsal fascicle: heterogomph falcigers blades with number
of teeth
156. Neurochaetae dorsal fascicle: simple chaetae (fused falcigers) (Fig. 4I, J)
[NEXUS: neurochaetae dorsal fascicle falcigers fused]
1. present.
2. absent.
157. Neurochaetae dorsal fascicle: simple chaetae (fused falcigers) present
from chaetiger
158. Neurochaetae dorsal fascicle: homogomph falcigers in anterior chaeti-
gers [NEXUS: neurochaetae dorsal fascicle homogomph falcigers anterior]
1. present.
2. absent.
159. Neurochaetae dorsal fascicle: homogomph falcigers on posterior chae-
tigers [NEXUS: neurochaetae dorsal fascicle homogomph falcigers posterior]
1. present.
2. absent.
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160. Neurochaetae ventral fascicle: sesquigomph falcigers [NEXUS: neuro-
chaetae ventral fascicle sesquigomph falcigers]
1. present.
2. absent.
161. Neurochaetae ventral fascicle: sesquigomph falcigers blade [NEXUS: neu-
rochaetae ventral fascicle sesquigomph falcigers bid]
1. distally bid.
2. with a single distal tooth.
162. Neurochaetae ventral fascicle: heterogomph spinigers [NEXUS: neuro-
chaetae ventral fascicle heterogomph spinigers]
1. present.
2. absent.
163. Neurochaetae ventral fascicle: heterogomph spinigers in anterior chaeti-
gers with blades [NEXUS: neurochaetae ventral fascicle heterogomph spinigers
anterior serrated]
1. evenly serrated throughout.
2. coarsely serrated proximally.
164. Neurochaetae ventral fascicle: heterogomph spinigers on posterior chae-
tigers with blades [NEXUS: neurochaetae ventral fascicle heterogomph spini-
gers posterior serrated] /
1. nely serrated proximally.
2. coarsely serrated proximally.
165. Neurochaetae ventral fascicle: homogomph spinigers [NEXUS: neuro-
chaetae ventral fascicle homogomph spinigers]
1. present.
2. absent.
166. Neurochaetae ventral fascicle: sesquigomph spinigers [NEXUS: neuro-
chaetae ventral fascicle sesquigomph spinigers]
1. present.
2. absent.
167. Neurochaetae ventral fascicle: heterogomph falcigers [NEXUS: neuro-
chaetae ventral fascicle heterogomph falcigers]
1. present.
2. absent.
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168. Neurochaetae ventral fascicle: heterogomph falcigers blade [NEXUS: neu-
rochaetae ventral fascicle heterogomph falcigers bowed]
1. tapering, with straight margin (Fig. 4G).
2. bowed, with convex margin (Fig. 4H).
This character was introduced by Villalobos-Guerrero et al. (2022a: g. 1e,
f) and is valuable for distinguishing Composetia and similar taxa. Other Nere-
ididae, for example many species illustrated in Pettibone (1971) appear inter-
mediate between bowed and straight-bladed forms or appear to be variable
depending on which chaetiger is examined and are dicult to score.
169. Neurochaetae ventral fascicle: anterior chaetigers heterogomph falcigers
with long blades (Fig. 4D) [NEXUS: neurochaetae ventral fascicle heterogomph
falcigers anterior long]
1. present.
2. absent.
Denitions of blade length of falcigers were introduced by Bakken and Wilson
(2005) depending on length of the free margin of the blade relative to the part
within the articulation (Fig. 4D–F) but has not been widely adopted. Here we use
simpler terms; “long blades” is equivalent to “Type 0” of Bakken and Wilson (2005).
170. Neurochaetae ventral fascicle: anterior chaetigers heterogomph falcigers
with extra-long blades (Fig. 4E) [NEXUS: neurochaetae ventral fascicle hetero-
gomph falcigers anterior xlong]
1. present.
2. absent.
The term “extra-long blades” is equivalent to “Type 1” of Bakken and Wilson(2005).
171. Neurochaetae ventral fascicle: anterior chaetigers heterogomph falcigers
with short blades (Fig. 4F) [NEXUS: neurochaetae ventral fascicle heterogomph
falcigers anterior short]
1. present.
2. absent.
The term “short blades” is equivalent to “Type 2” of Bakken and Wilson(2005).
172. Neurochaetae ventral fascicle: posterior chaetigers heterogomph fal-
cigers with long blades [NEXUS: neurochaetae ventral fascicle heterogomph
falcigers posterior long]
1. present.
2. absent.
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173. Neurochaetae ventral fascicle: posterior chaetigers heterogomph falcigers
with extra-long blades [NEXUS: neurochaetae ventral fascicle heterogomph fal-
cigers posterior xlong]
1. present.
2. absent.
174. Neurochaetae ventral fascicle: posterior chaetigers heterogomph fal-
cigers with short blades [NEXUS: neurochaetae ventral fascicle heterogomph
falcigers posterior short]
1. present.
2. absent.
175. Neurochaetae ventral fascicle: heterogomph falcigers blade [NEXUS: neu-
rochaetae ventral fascicle heterogomph falcigers tendon]
1. with recurved terminal tooth and distinct tendon.
2. lacking distinct tendon on terminal tooth.
176. Neurochaetae ventral fascicle: heterogomph falcigers blade [NEXUS: neu-
rochaetae ventral fascicle heterogomph falcigers bid]
1. terminally bid.
2. with a single terminal tooth.
177. Neurochaetae ventral fascicle: homogomph falcigers in anterior chaeti-
gers [NEXUS: neurochaetae ventral fascicle homogomph falcigers anterior]
1. present.
2. absent.
178. Neurochaetae ventral fascicle: homogomph falcigers on posterior
chaetigers [NEXUS: neurochaetae ventral fascicle homogomph falcigers
posterior]
1. present.
2. absent.
Pygidium and appendages – character 179
A trilobate pygidium is present in Namanereis while other Namanereidinae, and
some Nicon species, have a bilobate pygidium. Other nereidids are commonly
described as having a funnel-shaped pygidium, which may be crenulated or
multi-incised (perhaps indicating specimens approaching epitoky). For the
majority of Nereididae the form of the pygidium is unknown, often because
specimens were incomplete posteriorly. Thus, we have not included a character
describing the form of the pygidium.
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Robin S. Wilson et al.: The Nereidid worms
Figure 4. Chaetae A chaetal shaft homogomph articulation Perinereis vallata spiniger NMV F53971 B chaetal shaft het-
erogomph articulation Perinereis vallata falciger NMV F53971 (= long-bossed heterogomph sensu Conde-Vela (2021)
lled arrow points to boss C chaetal shaft sesquigomph articulation Ceratonereis mirabilis (= short-bossed heterogomph
sensu Conde-Vela (2021) lled arrow points to boss D heterogomph falcigers with long blades (a < b; = Type 0 of Bakken
and Wilson (2005)) E heterogomph falcigers with extra-long blades (2× a < b; = Type 1 of Bakken and Wilson (2005))
Fheterogomph falcigers with short blades (a ≥ b; = Type 2 of Bakken and Wilson (2005)) G heterogomph falciger blade
with straight margin H heterogomph falciger blade with bowed margin I fused heterogomph falciger chaetiger 70 Hediste
diversicolor complex AHF, Gilleleje, Denmark J fused falciger chaetiger 40 Simplisetia aequisetis NMV F53970 K homog-
omph falciger with terminal tendon (lled arrow) and with terminal secondary tooth (open arrow; = bid) Platynereis an-
tipoda notopodial falciger chaetiger 66 NMV F50116 L sesquigomph falciger with terminal tendon absent but bid with
secondary terminal tooth (open arrow) and boss (lled arrow) Ceratonereis mirabilis median chaetiger M homogomph
falciger with smooth blade Nereis cirriseta chaetiger 74 N homogomph falcigers with bidentate blade and large adjacent
terminal and subterminal teeth Nereis bida chaetiger 71 O homogomph falciger with bidentate blade and large wide-
ly-separated terminal and subterminal teeth Nereis triangularis chaetiger 24 P homogomph falciger with multidentate
blade with ≥ 2 large lateral teeth, rst lateral tooth subequal to terminal tooth, subsequent teeth decreasing in size Nereis
denhamensis anterior chaetiger Q homogomph falciger with multidentate blade with ≥ 2 small lateral teeth, rst and
subsequent lateral teeth much smaller than terminal tooth Nereis apalie chaetiger 74. Sources: A–F, I–K, M–J R. Wilson
drawings G, H edited after Villalobos-Guerrero et al. (2021: g. 1e, f) L after Perkins (1980: g. 1d) M–P redrawn after
Hutchings and Turvey (1982) Q after Wilson (1985: g. 1E). Not to scale; maximum widths of chaetal shafts (at articula-
tion) are in the range 0.01–0.03 mm.
179. Anal cirri form [NEXUS: anal cirri form]
1. cirriform or conical.
2. short, stout and appearing as an extension of the pygidium.
3. attened, resembling posterior dorsal cirri.
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Epitokal modications and reproduction – characters 180–186
Although some epitokal features may be diagnostic at the genus level (Pa-
mungkas and Glasby 2015), they are too poorly known across the family to
be used in the present keys. Read (2007), Pamungkas and Glasby (2015) and
Conde-Vela et al. (2018) demonstrated their utility in discriminating species
across several genera. The seven characters presented below represent the
basic characters for documenting epitokal reproductive forms.
180. Dorsal cirrophores of chaetigers 5–7 of epitokes [NEXUS: dorsal cirro-
phores chaetigers 5 7]
1. unmodied.
2. modied into attened elytriform discs.
3. modied into spherical globular structures.
181. Natatory region in males commences chaetiger
182. Natatory region in males comprises number of chaetigers
183. Natatory region in females commences chaetiger
184. Natatory region in females comprises number of chaetigers
185. Pygidium of male epitokes [NEXUS: pygidium of male epitokes]
1. unmetamorphosed.
2. with pygidial rosette.
Male epitokes may have the pygidium modied to form a pygidial rosette
with multiple rows of short papillae. The unmodied form is illustrated by Vil-
lalobos-Guerrero and Bakken (2018: gs 6E, 17L) and the pygidial rosette is
illustrated in Villalobos-Guerrero and Bakken (2018: g. 14C, D).
186. Oocyte shape [NEXUS: oocyte form]
1. spherical.
2. ovoid.
Oocytes are typically spherical in Nereididae but in many Namanereis spe-
cies they are ovoid.
Key to genera of Nereididae
It is easy to reach an incorrect identication using a linear (usually dichot-
omous) key – one always reaches a name, irrespective of errors that may
have been made. Thus, it is wise to doubt, and some form of verication
is highly desirable. Our recommendation is that after reaching a genus de-
termination using the key below, the next step should be to compare the
specimen at hand with the diagnosis of the genus that has been tentatively
identied; if specimen and diagnosis match, the user can have increased
condence in the identication. See Methods above for further discussion.
As discussed in the Introduction, several Nereididae genera are widely rec-
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ognised as likely para- or polyphyletic groups. They are polymorphic for
characters which distinguish other nereidid genera and therefore key out in
more than one couplet.
1(0) Maxillary ring paragnaths present (Fig. 1B) ............................................2
– Maxillary ring paragnaths absent (Fig. 1A) ...........................................24
2(1) Oral ring paragnaths present (Fig. 1J) .....................................................3
– Oral ring paragnaths absent (Fig. 1A) ....................................................13
3(2) Dorsal notopodial ligule markedly broader on posterior chaetigers
(Fig.3G) .....................................................................................................4
– Dorsal notopodial ligule not markedly broader on posterior chaetigers ....7
4(3) Palpophore barrel-shaped, approximately equal width from base to pal-
postyle (not overly large compared with palpostyle) (Fig. 1A); maxillary
ring of pharynx with P-bar paragnaths present, usually in regular comb-
like rows (Fig. 2A); Areas VI shield-shaped bars present (Fig.2G) ..........
...................................................................... Pseudonereis Kinberg, 1865
– Palpophore massive subconical, attened (palpostyle is minute by
comparison) (Fig. 1B); maxillary ring of pharynx with P-bar paragnaths
absent; Area VI shield-shaped bars absent .............................................5
5(4) Ventral peristomial ap present (Fig. 1L); Areas VII-VIII conical parag-
naths differentiated, with a separate band of minute paragnaths also
present; prechaetal notopodial lobe (Fig. 3B) restricted to a limited
number of anterior chaetigers ..................... Cheilonereis Benham, 1916
– Ventral peristomial ap absent; Areas VII-VIII conical paragnaths sim-
ilar in size, or irregular mix of large and small paragnaths in a single
band; prechaetal notopodial lobe (Fig. 3B) present on all chaetigers ...6
6(5) Notochaetae sesquigomph (Fig. 4C) spinigers present; neurochaetae
dorsal fascicle heterogomph (Fig. 4B) spinigers present; neurochaetae
dorsal fascicle sesquigomph (Fig. 4C) spinigers present ........................
................................................................... Nectoneanthes Imajima, 1972
– Notochaetae sesquigomph (Fig. 4C) spinigers absent; neurochaetae dor-
sal fascicle heterogomph (Fig. 4B) spinigers absent; neurochaetae dorsal
fascicle sesquigomph (Fig. 4C) spinigers absent. ........Alitta Kinberg, 1865
7(3) Antennae present; palpostyles present; maxillary ring of pharynx divid-
ed into discrete Areas (Fig. 1O, P) ............................................................8
– Antennae absent palpostyles absent (palps undivided, minute) maxil-
lary ring of pharynx undivided ................... Micronereis Claparède, 1863
8(7) Notochaetae homogomph falcigers (g. 4M–Q) present ......................9
– Notochaetae homogomph falcigers absent .........................................10
9(8) Area II rod-like paragnaths present (Fig. 2C); Area III rod-like paragnaths
present (Fig. 2C); Area IV conical paragnaths absent ..............................
.......................................................................... Platynereis Kinberg, 1865
– Area II rod-like paragnaths absent; Area III rod-like paragnaths absent;
Area IV conical paragnaths present (Fig. 2B) ......Nereis Linnaeus, 1758
10(8) Oral ring papillae present; neurochaetae dorsal fascicle heterogomph
falcigers in anterior chaetigers absent ......................................................
.......................... Imajimainereis de León-González & Solis-Weiss, 2000
– Oral ring papillae absent; neurochaetae dorsal fascicle heterogomph
falcigers (Fig. 4D–F) in anterior chaetigers present .............................11
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11(10) Area VI smooth bars present ...........................Perinereis Kinberg, 1865
– Area VI smooth bars absent ...................................................................12
12(11) Neurochaetae dorsal fascicle simple chaetae (fused falcigers) (Fig.4I)
present ............................................................... Hediste Malmgren, 1867
– Neurochaetae dorsal fascicle simple chaetae (fused falcigers) absent ....
................................................................................. Neanthes Kinberg, 1865
13(2) Oral ring papillae present ........................................................................14
– Oral ring papillae absent .........................................................................16
14(13) Ventral neuropodial ligule on posterior chaetigers similar to length of
acicular neuropodial ligule (Fig. 3E) ......................................................15
– Ventral neuropodial ligule on posterior chaetigers short, up to half
length of acicular neuropodial ligule (Fig. 3F, G) .......................................
.......................................................................Wuinereis Khlebovich, 1996
15(14) Neurochaetae dorsal fascicle homogomph (Fig. 4A) spinigers present ....
................................................................................Leonnates Kinberg, 1865
– Neurochaetae dorsal fascicle homogomph spinigers absent .................
......................................................Paraleonnates Khlebovich & Wu, 1962
16(13) Notochaetae sesquigomph (Fig. 4C) spinigers present; neurochaetae
dorsal fascicle homogomph (Fig. 4A) spinigers absent; prostomium an-
terior margin indented (Fig. 1G) .............................................................17
– Notochaetae sesquigomph spinigers absent; neurochaetae dorsal
fascicle homogomph (Fig. 4A) spinigers present; prostomium anterior
margin entire (Fig. 1G) ............................................................................18
17(16) Area II rod-like paragnaths (Fig. 4C) present; notochaetae homogomph
(Fig. 4A) falcigers present; Area I conical paragnaths present (Fig. 2B) ......
............................................................................ Solomononereis Gibbs, 1971
– Area II rod-like paragnaths absent; notochaetae homogomph falcigers
absent; Area I conical paragnaths absent .......Ceratonereis Kinberg, 1865
18(16) Notochaetae homogomph falcigers present ......Nereis Linnaeus, 1758
– Notochaetae homogomph falcigers absent ...........................................9
19(18) Neurochaetae dorsal fascicle heterogomph falcigers in anterior chaeti-
gers present (Fig. 4M–Q) .......................................................................20
– Neurochaetae dorsal fascicle heterogomph falcigers in anterior chaeti-
gers absent ..............................................................................................23
20(19) Neurochaetae dorsal fascicle simple chaetae (fused falcigers) (Fig.4J)
present ......................................... Simplisetia Hartmann-Schröder, 1985
– Neurochaetae dorsal fascicle simple chaetae (fused falcigers)
absent .................................................................................................. 21
21(20) Dorsal cirrus terminally attached to dorsal notopodial ligule (Fig. 3C)
on posterior chaetigers; neuropodial prechaetal lobe (Fig. 3B) present;
neuropodial postchaetal lobe attened (Fig. 3B) ...................................
................................................................................Unanereis Day, 1962
– Dorsal cirrus not terminally attached to dorsal notopodial ligule on
posterior chaetigers; neuropodial prechaetal lobe absent; neuropodial
postchaetal lobe digitiform (Fig. 3F) .....................................................22
22(21) Notoaciculae on chaetigers 1 and 2 present ............................................
................Potamonereis Villalobos-Guerrero, Conde-Vela & Sato, 2022
– Notoaciculae on chaetigers 1 and 2 absent ........................................
...................................................................... Neanthes Kinberg, 1865
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23(19) Palpophore barrel-shaped, approximately equal width from base to pal-
postyle (not overly large compared with palpostyle) (Fig. 1A); oesopha-
geal caeca present (Fig. 1C); jaws with dentate cutting edge (Fig. 1H) ..
.....................................................Composetia Hartmann-Schröder, 1985
– Palpophore massive subconical, attened (palpostyle is minute by
comparison) (Fig. 1B); oesophageal caeca absent; jaws with smooth or
slightly crenulate cutting edge (Fig. 1I) .....................................................
....................... Parasetia Villalobos-Guerrero, Conde-Vela & Sato, 2022
24(1) Prostomium anterior margin entire (Fig. 1F) .........................................25
– Prostomium anterior margin indented (Fig. 1G) ...................................41
25(24) Maxillary ring of pharynx with papillae present ....................................26
– Maxillary ring of pharynx with papillae absent ......................................29
26(25) Neurochaetae ventral fascicle sesquigomph (Fig. 4C) spinigers present .
......................................................................................................................27
– Neurochaetae ventral fascicle sesquigomph spinigers absent ...........28
27(26) Oral ring papillae present; tentacular cirri 3 pairs ventrum of anterior
chaetigers smooth (Fig. 1N)..............................Lycastonereis Rao, 1981
– Oral ring papillae absent; tentacular cirri 4 pairs; ventrum of anterior
chaetigers with rows of tubercles extending to the base of each neu-
ropodium (Fig. 1M) ..................................Australonereis Hartman, 1954
28(26) Area V papillae present; dorsal notopodial ligule divided into numer-
ous branchial laments (Fig. 3H); ventral neuropodial ligule of anterior
chaetigers absent ................................. Dendronereides Southern, 1921
– Area V papillae absent dorsal notopodial ligule not divided into numer-
ous branchial laments; ventral neuropodial ligule (Fig. 3E–G) of anteri-
or chaetigers present ...................Olganereis Hartmann-Schröder, 1977
29(25) Dorsal notopodial ligule (Fig. 3E–G) commences chaetiger 1 ................
......................................................................... Leptonereis Kinberg, 1865
– Dorsal notopodial ligule (Fig. 3E–G) commences chaetiger 3 ............30
– Dorsal notopodial ligule (Fig. 3E–G) commences chaetiger 4 ............38
– Dorsal notopodial ligule (Fig. 3E–G) commences chaetiger 5 ............40
30(29) Notochaetae homogomph falcigers (Fig. 4M–Q) present ...................31
– Notochaetae homogomph falcigers absent .........................................33
31(30) Oral ring paragnaths (Fig. 1O, P) present .......Eunereis Malmgren, 1865
– Oral ring paragnaths absent ...................................................................32
32(31) Dorsal notopodial ligule (Fig. 3E) markedly reduced on posterior chae-
tigers; neurochaetae ventral fascicle heterogomph (Fig. 4B) spinigers
absent ........................................................Rullierinereis Pettibone, 1971
– Dorsal notopodial ligule (Fig. 3E) not markedly reduced on posterior
chaetigers neurochaetae ventral fascicle heterogomph (Fig. 4B) spini-
gers present .............................................. Kainonereis Chamberlin, 1919
33(30) Oral ring paragnaths (Fig. 1O, P) present .......Eunereis Malmgren, 1865
– Oral ring paragnaths (Fig. 1O, P) absent ................................................34
34(33) Neuropodial postchaetal lobe (Fig. 3B, E) present ...............................35
– Neuropodial postchaetal lobe absent ....................................................36
35(34) Oral ring papillae present .......................Websterinereis Pettibone, 1971
– Oral ring papillae absent .......................................... Nicon Kinberg, 1865
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36(34) Dorsal notopodial ligule markedly broader on posterior chaetigers
(Fig.3G); dorsal cirrus terminally attached to dorsal notopodial ligule on
posterior chaetigers (Fig. 3C); dorsal notopodial ligule markedly elongate
on posterior chaetigers (Fig. 3C) ..................... Leptonereis Kinberg, 1865
– Dorsal notopodial ligule not markedly broader on posterior chaetigers
dorsal cirrus not terminally attached to dorsal notopodial ligule on pos-
terior chaetigers dorsal notopodial ligule not markedly elongate on pos-
terior chaetigers ......................................................................................37
37(36) Neurochaetae dorsal fascicle homogomph spinigers (Fig. 4A) present;
neurochaetae ventral fascicle sesquigomph (Fig. 4C) spinigers present;
palpophore surface with a single transverse groove (palpophores well
developed) (Fig. 1A) .......................................... Micronereides Day, 1963
– Neurochaetae dorsal fascicle homogomph (Fig. 4A) spinigers absent;
neurochaetae ventral fascicle sesquigomph spinigers (Fig. 4C) absent;
palpophore surface without grooves or striae (palps short, compact)
(Fig. 4D) ....................................................Namanereis Chamberlin, 1919
38(29) Dorsal notopodial ligule markedly broader on posterior chaetigers
(Fig.3G); dorsal cirrus terminally attached (Fig. 3G) to dorsal notopodi-
al ligule on posterior chaetigers; neuropodial postchaetal lobe absent..
......................................................................... Leptonereis Kinberg, 1865
– Dorsal notopodial ligule not markedly broader on posterior chaetigers
(Fig. 3E); dorsal cirrus not terminally attached to dorsal notopodial ligule
on posterior chaetigers; neuropodial postchaetal lobe present ............ 39
39(38) Notochaetae homogomph falcigers (Fig. 4A) present; neurochaetae
ventral fascicle falcigers blade bowed, with convex margin (Fig. 4H) ......
.................................................................... Kainonereis Chamberlin, 1919
– Notochaetae homogomph falcigers absent; neurochaetae ventral fas-
cicle falcigers blade tapering, with straight margin (Fig. 4G) ..................
........................................................................ Sinonereis Wu & Sun, 1979
40(29) Dorsal notopodial ligule markedly broader on posterior chaetigers
(Fig. 3E); dorsal notopodial ligule not markedly reduced on posterior
chaetigers; dorsal cirrus terminally attached to dorsal notopodial ligule
on posterior chaetigers (Fig. 3C) .................. Leptonereis Kinberg, 1865
– Dorsal notopodial ligule not markedly broader on posterior chaetigers;
dorsal notopodial ligule markedly reduced on posterior chaetigers; dor-
sal cirrus not terminally attached to dorsal notopodial ligule on posteri-
or chaetigers..................................................Typhlonereis Hansen, 1879
41(24) Dorsal cirrus simple, lacking basal cirrophore ......................................42
– Dorsal cirrus arising from basal cirrophore ...........................................46
42(41) Ventral neuropodial ligule on posterior chaetigers present (Fig.3E–G) ...43
– Ventral neuropodial ligule on posterior chaetigers absent ..................45
43(42) Maxillary ring of pharynx with papillae present; dorsal notopodial ligule
not markedly reduced on posterior chaetigers (Fig. 3E, F); notoaciculae
on chaetigers 1 and 2 absent .................................................................44
– Maxillary ring of pharynx with papillae absent; dorsal notopodial ligule
markedly reduced on posterior chaetigers notoaciculae on chaetigers 1
and 2 present ...........................................Kinberginereis Pettibone, 1971
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44(43) Dorsal notopodial ligule commences chaetiger 1; dorsal notopodial li-
gule not markedly broader on posterior chaetigers (Fig. 3E, F); maxillary
ring of pharynx with papillae in tufts ............Laeonereis Hartman, 1945
– Dorsal notopodial ligule commences chaetiger 3; dorsal notopodial li-
gule markedly broader on posterior chaetigers (Fig. 3G); maxillary ring
of pharynx with papillae solitary ........................Tylonereis Fauvel, 1911
45(42) Palpophore barrel-shaped, approximately equal width from base to
palpostyle (not overly large compared with palpostyle) (Fig. 1A); noto-
chaetae sesquigomph (Fig. 4C) spinigers present; neurochaetae dorsal
fascicle homogomph spinigers absent ....... Tylorrhynchus Grube, 1866
– Palpophore massive subconical, attened (palpostyle is minute by com-
parison) (Fig. 1B); notochaetae sesquigomph spinigers absent; neuro-
chaetae dorsal fascicle homogomph (Fig. 4A) spinigers present ...............
..............................................................................Dendronereis Peters, 1854
46(41) Oral ring papillae present notoaciculae on chaetigers 1 and 2 absent; ven-
tral neuropodial ligule of anterior chaetigers present (Fig. 3E–G)...........47
– Oral ring papillae absent notoaciculae on chaetigers 1 and 2 present;
ventral neuropodial ligule of anterior chaetigers absent ......................49
47(46) Dorsal notopodial ligule (Fig. 3E) present, commences chaetiger 1 .....48
– dorsal notopodial ligule absent .............Ceratocephale Malmgren, 1867
48(47) Notochaetae sesquigomph (Fig. 4C) spinigers present; neurochaetae
ventral fascicle sesquigomph (Fig. 4C) spinigers present; neurochaetae
dorsal fascicle sesquigomph (Fig. 4C) spinigers present ........................
........................................................................... Gymnonereis Horst, 1919
– Notochaetae sesquigomph spinigers absent; neurochaetae ventral fas-
cicle sesquigomph spinigers absent; neurochaetae dorsal fascicle ses-
quigomph spinigers absent ........................... Tambalagamia Pillai, 1961
49(46) Neuropodial postchaetal lobe (Fig. 3B, F) present; antennae form cir-
riform (usually extending to or past palpophore) (Fig. 1G); palpophore
surface with a single transverse groove (palpophores well developed)
(Fig. 1A) ....................................... Stenoninereis Wesenberg-Lund, 1958
– Neuropodial postchaetal lobe absent antennae form subconical (usu-
ally shorter than palpophore) (Fig. 1F); palpophore surface without
grooves or striae (palps short, compact) (Fig. 1D) ...................................
..................................................................... Namalycastis Hartman, 1959
Systematic account of Nereididae genera
Alitta Kinberg, 1865
Nereis (Alitta) auctt.
Type species. Nereis virens Sars, 1835.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=234848.
Sources. Villalobos-Guerrero and Carrera-Parra (2015); Villalobos-Guerrero
and Bakken (2018).
Diagnosis. Dorsal notopodial ligule markedly broader on posterior chaeti-
gers; palpophore massive subconical, attened (palpostyle is minute by com-
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parison); ventral peristomial ap absent; notochaetae sesquigomph spinigers
absent (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore massive subconical, attened (palpostyle is minute by
comparison). Palpophore surface with a single transverse groove (palpophores
well developed) or with several oblique grooves or striae (palpophores well de-
veloped); palpostyles subconical. Prostomium anterior margin entire. Tentacular
belt greater than length of chaetiger 1. Tentacular cirri cirrophores present.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present (absent occasionally in some spec-
imens of A. virens species complex); II conical paragnaths present; III conical
paragnaths present; III rod-like paragnaths absent; IV paragnaths present; IV
conical paragnaths present; IV smooth bar-like paragnaths absent. Oral ring
papillae absent. Oral ring paragnaths present; with Areas V, VI, and VII-VIII dis-
crete. Oral ring pyramidal paragnaths absent, or present. Area V conical parag-
naths present, or absent; arranged in a longitudinal line, or irregularly. Area VI
paragnaths present; paragnaths arranged in a roughly circular group, or in lines
or arcs; conical paragnaths present. Areas VII-VIII paragnaths present; conical
paragnaths present; P-bar paragnaths absent, or present.
Dorsal notopodial ligule markedly elongate on posterior chaetigers, or not
markedly elongate on posterior chaetigers; markedly broader on posterior
chaetigers; not markedly reduced on posterior chaetigers. Prechaetal notopo-
dial lobe present; smaller than dorsal notopodial ligule on anterior chaetigers,
usually reduced or absent posteriorly, or approximately equal to length of dor-
sal notopodial ligule at least on anterior chaetigers (thus notopodium of three
similar sized ligules/lobes); present on all chaetigers. Notopodial acicular pro-
cess absent. Dorsal cirrus sub-terminally attached to dorsal margin of dorsal
notopodial ligule on posterior chaetigers; not terminally attached to dorsal no-
topodial ligule on posterior chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
projecting beyond end of the acicular ligule; present throughout all chaetigers;
digitiform. Ventral neuropodial ligule of anterior chaetigers present. Ventral
neuropodial ligule of anterior chaetigers approx. as long as acicular neuropodi-
al ligule. Ventral neuropodial ligule on posterior chaetigers present. Ventral neu-
ropodial ligule on posterior chaetigers similar to length of acicular neuropodial
ligule, or short, up to half length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 present, or absent. Notochaetae of
chaetigers 3 and 4 present. Notochaetae: homogomph spinigers present.
Neurochaetae dorsal fascicle: heterogomph spinigers absent; homogomph
spinigers present; dorsal fascicle heterogomph falcigers in anterior chaeti-
gers present; on posterior chaetigers present, or absent. Neurochaetae ven-
tral fascicle: heterogomph spinigers present; spinigers in anterior chaetigers
with blades evenly serrated throughout; on posterior chaetigers with blades
nely serrated proximally; heterogomph falcigers present; anterior chaeti-
gers heterogomph falcigers with long blades absent; anterior chaetigers
heterogomph falcigers with extra-long blades present; anterior chaetigers
heterogomph falcigers with short blades absent; posterior chaetigers hetero-
gomph falcigers with long blades absent; posterior chaetigers heterogomph
falcigers with extra-long blades present; posterior chaetigers heterogomph
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falcigers with short blades absent; ventral fascicle heterogomph falcigers
blade with recurved terminal tooth and distinct tendon, or lacking distinct
tendon on terminal tooth; ventral fascicle heterogomph falcigers blade with
a single terminal tooth.
Anal cirri form cirriform or conical.
Remarks. The modern concept of Alitta is due to Khlebovich (1996) but
the generic description and the species included have been emended by Vil-
lalobos-Guerrero and Carrera-Parra (2015) and Villalobos-Guerrero and Bakken
(2018); the description here is based on that of the latter two studies. Alitta now
contains eight species all occurring in either the North Pacic or North Atlantic
Oceans. Alitta succinea (Leuckart, 1847) has been reported as a supposed in-
troduced species from numerous cosmopolitan localities but as summarised
by Villalobos-Guerrero and Carrera-Parra (2015: 165–166) many of these repre-
sent misidentications of related species.
There is no identication guide for all species of Alitta but the four species in
the A. virens species complex can be identied using the keys to atokes and to
epitokes in Villalobos-Guerrero and Bakken (2018).
Australonereis Hartman, 1954
Type species. Nereis (Leonnates) ehlersi Augener, 1913.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324844.
Sources. Hutchings and Reid (1990).
Diagnosis. Ventrum of anterior chaetigers with rows of tubercles extending
to the base of each neuropodium (minimal diagnosis). Dorsal notopodial ligule
commences chaetiger 1; prostomium anterior margin entire; maxillary ring of
pharynx with papillae present (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from base
to palpostyle (not overly large compared with palpostyle). Ventrum of anterior
chaetigers with rows of tubercles extending to the base of each neuropodium.
Maxillary ring of pharynx with papillae present (sometimes with horny tips);
solitary; 50–110 papillae in total. Maxillary ring paragnaths absent. Oral ring
papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule present; commences chaetiger 1; not markedly elon-
gate on posterior chaetigers; not markedly broader on posterior chaetigers; not
markedly reduced on posterior chaetigers. Prechaetal notopodial lobe present;
smaller than dorsal notopodial ligule on anterior chaetigers, usually reduced or
absent posteriorly; restricted to a limited number of anterior chaetigers. Notopodi-
al acicular process absent. Dorsal cirrus not sub-terminally attached to dorsal no-
topodial ligule on posterior chaetigers; not terminally attached to dorsal notopodi-
al ligule on posterior chaetigers; not terminally attached throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
projecting beyond end of the acicular ligule; digitiform. Ventral neuropodial ligu-
le of anterior chaetigers present.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers absent;
homogomph spinigers present; sesquigomph spinigers present. Neurochaetae
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dorsal fascicle: sesquigomph falcigers present; blades serrated; heterogomph
falcigers in anterior chaetigers absent; on posterior chaetigers absent. Neuro-
chaetae ventral fascicle: sesquigomph falcigers present; heterogomph spini-
gers absent; homogomph spinigers absent; sesquigomph spinigers present;
heterogomph falcigers absent.
Anal cirri form cirriform or conical.
Remarks. Australonereis is a monotypic genus. The single species A. ehlersi
(Augener, 1913) occurs only in southern Australian estuaries where these large
and often locally abundant worms are instantly recognisable by the conspicu-
ous rows of tuberculae on the ventral surface; living specimens are also much
more fragile than those belonging to other genera of Nereididae and readily
fragment in the eld.
Ceratocephale Malmgren, 1867
Chaunorhychus Chamberlin, 1919.
Pisionura Hartman & Fauchald, 1971.
Type species. Ceratocephale loveni Malmgren, 1867.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129371.
Sources. Hylleberg and Nateewathana (1988); Hutchings and Reid (1990:
table 9); Santos (2007).
Diagnosis. Transverse dorsal lamellae present; dorsal notopodial ligule ab-
sent (minimal diagnosis). Dorsal cirrus arising from basal cirrophore; dorsal
notopodial ligule commences chaetiger 3 (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpostyles
subconical, or acutely conical. Eyes present, or absent. Prostomium anterior
margin indented. Tentacular belt equal to or less than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae present. Oral ring papillae arrangement solitary. Area V
three papillae present (close together); VI papillae present, or absent; VII-VIII
seven papillae present, arranged in a single row. Oral ring paragnaths absent.
In Ceratocephale spp., Areas V and VI contain up to three papillae in total; these
are here interpreted as all occurring in Area V, with VI = 0,0.
Transverse dorsal lamellae present (in all species except C. abyssorum);
commencing chaetiger 4–10.
Dorsal notopodial ligule absent. Prechaetal notopodial lobe present; pres-
ent on all chaetigers. Notopodial acicular process absent. Dorsal cirrus arising
from basal cirrophore; cirrophore of dorsal cirrus enlarged and vascularised;
cirrophore of dorsal cirrus expanded and leaike.
Neuropodial postchaetal lobe present; projecting beyond end of the acicular
ligule; present throughout all chaetigers; digitiform. Ventral neuropodial ligule
of anterior chaetigers present. Ventral neuropodial ligule of anterior chaetigers
approx. as long as acicular neuropodial ligule, or short, up to half length of
acicular neuropodial ligule. Ventral neuropodial ligule on posterior chaetigers
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present. Ventral neuropodial ligule on posterior chaetigers short, up to half
length of acicular neuropodial ligule. Accessory ventral cirrus present; com-
mencing chaetiger 1–3. Conspicuous neuropodial prechaetal ligule present.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present; sesquigomph spinigers present, or absent. Neurochaetae dor-
sal fascicle: heterogomph spinigers absent; homogomph spinigers present;
sesquigomph spinigers present; heterogomph falcigers in anterior chaetigers
absent; on posterior chaetigers absent. Neurochaetae ventral fascicle: hetero-
gomph spinigers absent; homogomph spinigers present, or absent; hetero-
gomph falcigers absent.
Anal cirri form cirriform or conical.
Remarks. The denition of Ceratocephale used here follows Santos (2007).
Bakken et al. (2022) noted the possible synonymy of Tambalagamia Pillai, 1961
and suggested that a revision was required. Further evidence of morphological
diversity of key characters also suggests that Ceratocephale as presently con-
stituted may not be a natural group: according to Santos et al. (2005), in Cerato-
cephale the tentacular belt is shorter than the subsequent chaetigers however
this is not so for all species: e.g. Ceratocephale papillata de León-González &
Góngora-Garza, 1992, nor in C. loveni Malmgren, 1867 or C. pacica (Hartman,
1960) based on Hilbig (1997); and C. bansei Khlebovich, 1966 may be the only
species of Ceratocephale with papillae on Area VI of the pharynx.
Ceratocephale currently includes 12 accepted species recorded from all
oceans except the Arctic Ocean and from intertidal to abyssal depths (Read
and Fauchald 2023). There is no identication guide to all species although
Hylleberg and Nateewathana (1988) have a key to the six species then known.
Hutchings and Reid (1990) allow identication of the three Australian species
currently described although we know of two additional undescribed Australian
Ceratocephale species.
Ceratonereis Kinberg, 1865
Ceratonereis (Ceratonereis) auctt.
Type species. Ceratonereis mirabilis Kinberg, 1865.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129372.
Sources. Hartmann-Schröder (1985).
Diagnosis. Notochaetae: sesquigomph falcigers present; dorsal cirrus
sub-terminally attached to dorsal margin of dorsal notopodial ligule on posterior
chaetigers (minimal diagnosis). Neurochaetae dorsal fascicle: sesquigomph fal-
cigers present; palpophore barrel-shaped, approximately equal width from base
to palpostyle (not overly large compared with palpostyle) (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle) (elongate). Pal-
pophore surface with a single transverse groove (palpophores well developed).
Prostomium anterior margin indented.
Oesophageal caeca absent.
Jaws with dentate cutting edge.
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Maxillary ring of pharynx with papillae absent. Area I conical paragnaths ab-
sent; II conical paragnaths present; III conical paragnaths present; IV parag-
naths present; IV conical paragnaths present. Oral ring papillae absent. Oral
ring paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; markedly reduced on posterior chae-
tigers, or not markedly reduced on posterior chaetigers. Prechaetal notopodial
lobe absent. Notopodial acicular process absent. Dorsal cirrus sub-terminally
attached to dorsal margin of dorsal notopodial ligule on posterior chaetigers;
arising from basal cirrophore; cirrophore of dorsal cirrus short, at most as long
as ventral notopodial ligule, or much longer than ventral notopodial ligule; cirro-
phore of dorsal cirrus not enlarged and vascularised; cirrophore of dorsal cirrus
cylindrical throughout.
Neuropodial postchaetal lobe present; projecting beyond end of the acicular
ligule; restricted to anterior chaetigers; digitiform or attened. Ventral neuropo-
dial ligule of anterior chaetigers present. Ventral neuropodial ligule of anterior
chaetigers approx. as long as acicular neuropodial ligule, or short, up to half
length of acicular neuropodial ligule. Ventral neuropodial ligule on posterior
chaetigers present. Ventral neuropodial ligule on posterior chaetigers similar
to length of acicular neuropodial ligule, or short, up to half length of acicular
neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph spin-
igers absent; sesquigomph spinigers present; sesquigomph falcigers present;
blade distally bid, or with a single distal tooth. Neurochaetae dorsal fascicle:
heterogomph spinigers absent; homogomph spinigers absent; sesquigomph
spinigers present; sesquigomph falcigers present; heterogomph falcigers in
anterior chaetigers present. Neurochaetae ventral fascicle: heterogomph spin-
igers present; homogomph spinigers absent; heterogomph falcigers present;
anterior chaetigers heterogomph falcigers with short blades absent; hetero-
gomph falcigers blade lacking distinct tendon on terminal tooth; heterogomph
falcigers blade terminally bid, or with a single terminal tooth.
Anal cirri form cirriform or conical.
Remarks. Ceratonereis as currently dened follows the concept of Perkins
(1980) and Hartmann-Schröder (1985). Previously the genus (“Ceratonereis
sensu lato”) had included unrelated nereidid species with supercially simi-
lar paragnath conguration. Those disparate species (none of which have the
indented prostomium characteristic of Ceratonereis sensu stricto) are now
moved to genera Composetia Hartmann-Schröder (1985) and Simplisetia Hart-
mann-Schröder (1985). This restricted denition of Ceratonereis is probably
monophyletic (Bakken and Wilson 2005) and comprises 43 species which are
known from all oceans (Read and Fauchald 2023).
There is no identication guide to the species of Ceratonereis and many
nominal species are poorly known and some still may belong to other genera.
Distinguishing species relies heavily on differences in chaetae and in parapodi-
al structures; pigmentation pattern in living specimens is often distinctive and
would probably be most helpful.
Conde-Vela (2021) includes a key to American species of Ceratonereis. Glas-
by (2015) provides a key that includes four species of Ceratonereis known from
tropical Australia.
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Robin S. Wilson et al.: The Nereidid worms
Cheilonereis Benham, 1916
Type species. Nereis cyclurus Harrington, 1897.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=156851.
Sources. Bakken et al. (2022).
Diagnosis. Ventral peristomial ap present (minimal diagnosis). Areas VII-
VIII conical paragnaths differentiated, with a separate band of minute parag-
naths also present; dorsal notopodial ligule markedly broader on posterior
chaetigers (secondary diagnosis).
Description. Palpophore massive subconical, attened (palpostyle is minute
by comparison). Tentacular belt greater than length of chaetiger 1. Ventral peri-
stomial ap present.
Oesophageal caeca present.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present; II conical paragnaths present; IV
paragnaths present; IV conical paragnaths present. Oral ring papillae absent.
Oral ring paragnaths present; with Areas V, VI and VII-VIII discrete; on Area V
and VI form distinct groups. Area V conical paragnaths absent. Area VI parag-
naths present; paragnaths arranged in a roughly circular group; conical parag-
naths present; smooth bars absent. Areas VII-VIII paragnaths present; conical;
arranged in isolated patches, or in one or more irregular lines forming a contin-
uous band; conical paragnaths differentiated, with a separate band of minute
paragnaths also present (present as patches in C. peristomialis).
Dorsal notopodial ligule markedly elongate on posterior chaetigers; marked-
ly broader on posterior chaetigers; not markedly reduced on posterior chaeti-
gers. Prechaetal notopodial lobe present; smaller than dorsal notopodial ligule
on anterior chaetigers, usually reduced or absent posteriorly; restricted to a
limited number of anterior chaetigers. Dorsal cirrus sub-terminally attached to
dorsal margin of dorsal notopodial ligule on posterior chaetigers.
Neuropodial postchaetal lobe absent, or present; projecting beyond end of
the acicular ligule; present throughout all chaetigers; attened. Ventral neuropo-
dial ligule of anterior chaetigers present. Ventral neuropodial ligule of anterior
chaetigers approx. as long as acicular neuropodial ligule. Ventral neuropodial
ligule on posterior chaetigers present. Ventral neuropodial ligule on posterior
chaetigers similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present; homogomph falcigers present; homogomph falcigers with multi-
dentate blade with two or more small lateral teeth, rst and subsequent lateral
teeth much smaller than terminal tooth present. Neurochaetae dorsal fascicle:
heterogomph spinigers absent; homogomph spinigers present; heterogomph
falcigers in anterior chaetigers present; on posterior chaetigers present; blades
serrated. Neurochaetae ventral fascicle: heterogomph spinigers present; ho-
mogomph spinigers absent; heterogomph falcigers present; anterior chae-
tigers heterogomph falcigers with long blades absent; anterior chaetigers
heterogomph falcigers with extra-long blades present; anterior chaetigers
heterogomph falcigers with short blades absent; posterior chaetigers hetero-
gomph falcigers with long blades present; posterior chaetigers heterogomph
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falcigers with extra-long blades absent; posterior chaetigers heterogomph fal-
cigers with short blades absent; heterogomph falcigers blade lacking distinct
tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. The genus Cheilonereis has two species, C. cyclurus (Harrington,
1897) from the NW Pacic and C. peristomialis Benham, 1916 from the SE Pa-
cic; both species are commensals of hermit crabs. Cheilonereis species are
characterised by the presence of a ventral collar or ap that partly covers the
ventral paragnaths of the oral ring when the pharynx is extended (see photo by
Dave Cowles, Walla Walla University: https://inverts.wallawalla.edu/Annelida/
Nereidae/Cheilonereis_cyclurus_DLC2018-13.jpg also included as part of Wil-
son et al. (2023)); this structure is unknown in other Nereididae and it is plausi-
ble that the ventral ap is adaptive in some way for their commensal life style.
Composetia Hartmann-Schröder, 1985
Ceratonereis (Composetia) Hartmann-Schröder, 1985.
Type species. Nereis costae Grube, 1840.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324848.
Sources. Villalobos-Guerrero et al. (2022a).
Diagnosis. Neurochaetae ventral fascicle homogomph spinigers present;
maxillary ring paragnaths present; oral ring paragnaths absent; Neurochaetae
dorsal fascicle: heterogomph falcigers in anterior chaetigers absent; oesoph-
ageal caeca present (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore
surface with a single transverse groove (palpophores well developed). Pros-
tomium longitudinal groove present; anterior region entire, sub-quadrangular,
longitudinal groove present; prostomial posterior region subequal to or longer
than anterior region. Tentacular belt greater than length of chaetiger 1.
Oesophageal caeca present.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present; II conical paragnaths present; III
conical paragnaths present; IV paragnaths present; IV conical paragnaths pres-
ent. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule not markedly broader on posterior chaetigers; not
markedly reduced on posterior chaetigers. Prechaetal notopodial lobe present;
smaller than dorsal notopodial ligule on anterior chaetigers, usually reduced or
absent posteriorly; present on all chaetigers, or restricted to a limited number
of anterior chaetigers. Notopodial acicular process absent. Dorsal cirrus not
sub-terminally attached to dorsal notopodial ligule on posterior chaetigers.
Neuropodial postchaetal lobe present; projecting beyond end of the acicular
ligule; restricted to anterior chaetigers. Ventral neuropodial ligule of anterior
chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx.
as long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior
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chaetigers present. Ventral neuropodial ligule on posterior chaetigers similar to
length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers absent;
homogomph spinigers present; heterogomph falcigers in anterior chaetigers
absent; on posterior chaetigers absent. Neurochaetae ventral fascicle: hetero-
gomph spinigers absent; homogomph spinigers present; heterogomph falcigers
present; falcigers blade tapering, with straight margin; anterior chaetigers het-
erogomph falcigers with long blades absent; anterior chaetigers heterogomph
falcigers with extra-long blades present; anterior chaetigers heterogomph fal-
cigers with short blades absent; posterior chaetigers heterogomph falcigers
with long blades absent; posterior chaetigers heterogomph falcigers with ex-
tra-long blades present; posterior chaetigers heterogomph falcigers with short
blades absent; heterogomph falcigers blade lacking distinct tendon on terminal
tooth; homogomph falcigers on posterior chaetigers present, or absent.
Anal cirri form cirriform or conical.
Remarks. The description here follows the revised concept of Composetia
of Villalobos-Guerrero et al. (2022a) who removed several former species of
Composetia sensu Hartmann-Schröder, 1985 to two new genera: Parasetia and
Potamonereis. Composetia currently includes 11 species which collectively are
widely distributed around the globe; however, many species have not yet been
re-evaluated against the revised concept of Villalobos-Guerrero et al. (2022a)
the genus remains as an assemblage of dissimilar species Villalobos-Guerrero
et al. (2022a).
The only identication guide is the tabular comparisons of Villalobos-Guer-
rero et al. (2022a).
Dendronereides Southern, 1921
Type species. Dendronereides heteropoda Southern, 1921.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=206894.
Sources. Southern (1921); Hutchings and Reid (1990).
Diagnosis. Dorsal notopodial ligule divided into numerous branchial la-
ments (minimal diagnosis).
Ventral neuropodial ligule of anterior chaetigers absent; maxillary ring of pharynx
with papillae present; prostomium anterior margin entire (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore
surface with a single transverse groove (palpophores well developed).
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae present; solitary. Maxillary ring parag-
naths absent. Oral ring papillae present. Oral ring papillae arrangement solitary.
Area V papillae present; VI papillae present; VII-VIII papillae present. Oral ring
paragnaths absent.
Dorsal notopodial ligule present. Dorsal notopodial ligule divided into numerous
branchial laments. Dorsal cirrus not sub-terminally attached to dorsal notopodial
ligule on posterior chaetigers; not terminally attached throughout all chaetigers.
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Ventral neuropodial ligule of anterior chaetigers absent. Ventral neuropodial
ligule on posterior chaetigers absent.
Notochaetae: homogomph spinigers present; sesquigomph spinigers pres-
ent, or absent. Neurochaetae dorsal fascicle: heterogomph spinigers present,
or absent; homogomph spinigers present; sesquigomph spinigers present, or
absent; heterogomph falcigers in anterior chaetigers present, or absent; ho-
mogomph falcigers in anterior chaetigers present, or absent. Neurochaetae
ventral fascicle: heterogomph spinigers present, or absent; homogomph spin-
igers present, or absent; heterogomph falcigers present, or absent; hetero-
gomph falcigers blade lacking distinct tendon on terminal tooth; homogomph
falcigers on posterior chaetigers present, or absent.
Remarks. Dendronereides is the only nereidid genus in which the dorsal no-
topodial ligule is transformed into “branchial” laments; the genus contains
three species which occur in tropical estuaries of the Indo-Pacic. There is no
taxonomic review or identication guide for the species of Dendronereides.
Dendronereis Peters, 1854
Type species. Dendronereis arborifera Peters, 1854.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=206700.
Sources. Hsueh (2019b).
Diagnosis. Dorsal cirrus divided into numerous branchial laments (minimal
diagnosis). Ventral neuropodial ligule on posterior chaetigers absent; palpo-
phore massive subconical, attened (palpostyle is minute by comparison);
prostomium anterior margin indented (secondary diagnosis).
Description. Palpophore massive subconical, attened (palpostyle is minute
by comparison). Prostomium anterior margin indented.
Maxillary ring of pharynx with papillae present, or absent. Maxillary ring
paragnaths absent. Oral ring papillae present. Oral ring paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; not markedly reduced on posterior
chaetigers. Prechaetal notopodial lobe present; smaller than dorsal notopodial
ligule on anterior chaetigers, usually reduced or absent posteriorly. Dorsal cir-
rus divided into numerous branchial laments. Dorsal cirrus not sub-terminally
attached to dorsal notopodial ligule on posterior chaetigers; not terminally at-
tached to dorsal notopodial ligule on posterior chaetigers; not terminally at-
tached throughout all chaetigers.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodi-
al ligule of anterior chaetigers approx. as long as acicular neuropodial ligule.
Ventral neuropodial ligule on posterior chaetigers absent. Neuropodia of bran-
chial chaetigers divided into ve lobes, plus ventral cirrus, plus two smaller cirri
on ventral neuropodial lobe (not arising from same location as ventral cirri).
Posteriorly becoming simpler, eventually with a single neuropodial lobe and
ventral cirrus.
Notochaetae: homogomph spinigers present. Neurochaetae dorsal fascicle:
heterogomph spinigers absent; homogomph spinigers present; heterogomph
falcigers in anterior chaetigers absent; on posterior chaetigers absent. Neu-
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rochaetae ventral fascicle: heterogomph spinigers absent; homogomph spini-
gers present; heterogomph falcigers absent.
Remarks. Species belonging to Dendronereis are easily recognised as this
is the only genus of Nereididae in which the dorsal cirrus is transformed into
branchial laments. Bakken et al. (2022) incorrectly stated that maxillary ring
paragnaths may be present or absent; they are always absent as per the cor-
rected description and diagnosis above.
Five species of Dendronereis are known, all occurring in shallow waters of
the Indo-Pacic. Hsueh (2019b) provides a key to all known species.
Eunereis Malmgren, 1865
Nereis (Eunereis) Malmgren, 1865.
Type species. Nereis longissima Johnston, 1840.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129373.
Sources. Hsueh (2018); Bakken et al. (2022).
Diagnosis. Oral ring paragnaths present; maxillary ring paragnaths absent
(minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore sur-
face with a single transverse groove (palpophores well developed). Tentacular
belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae present, or absent. Oral ring paragnaths present; with
Areas V, VI, and VII-VIII discrete, or comprising a continuous ring dorsally and
ventrally, discrete groups not recognisable; on Areas V and VI form distinct
groups. Area V conical paragnaths present, or absent. Area VI paragnaths pres-
ent; arranged in a roughly circular group; conical paragnaths present, or absent;
smooth bars present, or absent. Areas VII-VIII paragnaths present, or absent;
conical paragnaths present; conical paragnaths arranged in isolated patches,
or in one or more irregular lines forming a continuous band; conical paragnaths
similar in size, or irregular mix of large and small paragnaths in a single band;
rod-shaped paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; markedly reduced on posterior chae-
tigers, or not markedly reduced on posterior chaetigers. Prechaetal notopodial
lobe present, or absent; smaller than dorsal notopodial ligule on anterior chaeti-
gers, usually reduced or absent posteriorly; restricted to a limited number of an-
terior chaetigers. Notopodial acicular process present, or absent. Dorsal cirrus
not sub-terminally attached to dorsal notopodial ligule on posterior chaetigers;
not terminally attached to dorsal notopodial ligule on posterior chaetigers; not
terminally attached throughout all chaetigers; simple, lacking basal cirrophore.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe absent,
or present; projecting beyond end of the acicular ligule; restricted to anterior
chaetigers; digitiform. Ventral neuropodial ligule of anterior chaetigers present.
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Ventral neuropodial ligule of anterior chaetigers approx. as long as acicular
neuropodial ligule. Ventral neuropodial ligule on posterior chaetigers present.
Ventral neuropodial ligule on posterior chaetigers similar to length of acicular
neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present; homogomph falcigers present, or absent. Neurochaetae dorsal
fascicle: heterogomph spinigers absent; homogomph spinigers present; hetero-
gomph falcigers in anterior chaetigers present; on posterior chaetigers present;
blades serrated. Neurochaetae ventral fascicle: heterogomph spinigers present;
homogomph spinigers absent; heterogomph falcigers present; falcigers blade
tapering, with straight margin; anterior chaetigers heterogomph falcigers with
long blades absent; anterior chaetigers heterogomph falcigers with extra-long
blades present; anterior chaetigers heterogomph falcigers with short blades ab-
sent; posterior chaetigers heterogomph falcigers with long blades present, or
absent; posterior chaetigers heterogomph falcigers with extra-long blades pres-
ent, or absent; posterior chaetigers heterogomph falcigers with short blades
absent; heterogomph falcigers blade lacking distinct tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. The description here follows Hsueh (2018) with additional infor-
mation on the straight/bowed blade falcigers character introduced (for Com-
posetia) by Villalobos-Guerrero et al. (2022a).
Eunereis is the only Nereididae genus with paragnaths present only on the
oral ring. Eunereis includes species which in other respects, especially chaetal
characters, are similar to either of the genera Neanthes or Nereis suggesting a
review is necessary.
Eunereis includes ten accepted species which encompass wide geographic and
bathymetric distributions. There is no published identication guide to all species.
Gymnonereis Horst, 1919
Gymnorhynchus Horst, 1919 (replaced homonym).
Type species. Gymnorhynchus sibogae Horst, 1918.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324851.
Sources. Pettibone (1970); Hutchings and Reid (1990).
Diagnosis. Accessory ventral cirrus present; neurochaetae ventral fascicle
sesquigomph spinigers present (minimal diagnosis). Notochaetae sesquigo-
mph spinigers present; dorsal notopodial ligule present (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore sur-
face with a single transverse groove (palpophores well developed); palpostyles
subconical, or acutely conical. Prostomium anterior margin indented.
Jaws with smooth or slightly crenulate cutting edge or with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae present. Oral ring papillae arrangement solitary. Area V
papillae present; VI papillae present; VII-VIII papillae present. Oral ring parag-
naths absent.
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Transverse dorsal lamellae absent, or present.
Dorsal notopodial ligule present; commences chaetiger 1; not markedly
elongate on posterior chaetigers; not markedly broader on posterior chaeti-
gers; markedly reduced on posterior chaetigers (but cirrophore of dorsal cirrus
is expanded and looks like an expanded notopodial lobe unless progressive
change is noted over many chaetigers). Prechaetal notopodial lobe present;
smaller than dorsal notopodial ligule on anterior chaetigers, usually reduced
or absent posteriorly; present on all chaetigers. Notopodial acicular process
present. Dorsal cirrus not sub-terminally attached to dorsal notopodial ligule
on posterior chaetigers; not terminally attached to dorsal notopodial ligule on
posterior chaetigers; not terminally attached throughout all chaetigers; arising
from basal cirrophore.
Neuropodial prechaetal lobe present; extending beyond postchaetal lobe (at
least in anterior chaetigers). Neuropodial postchaetal lobe present; not project-
ing beyond end of the acicular ligule; present throughout all chaetigers; attened.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodial li-
gule of anterior chaetigers approx. as long as acicular neuropodial ligule. Ventral
neuropodial ligule on posterior chaetigers present. Ventral neuropodial ligule on
posterior chaetigers similar to length of acicular neuropodial ligule, or short, up
to half length of acicular neuropodial ligule. Accessory ventral cirrus present.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present, or absent; sesquigomph spinigers present. Neurochaetae dor-
sal fascicle: heterogomph spinigers absent; homogomph spinigers present,
or absent; sesquigomph spinigers present. Neurochaetae dorsal fascicle: ses-
quigomph falcigers present, or absent; blades serrated; heterogomph falcigers
in anterior chaetigers absent; on posterior chaetigers absent. Neurochaetae
ventral fascicle: sesquigomph falcigers present, or absent; heterogomph spini-
gers absent; homogomph spinigers present, or absent; sesquigomph spinigers
present; heterogomph falcigers absent.
Anal cirri form cirriform or conical.
Remarks. The genus Gymnonereis is diagnosed by the presence of accesso-
ry dorsal and ventral cirri and notochaetae comprising sesquigomph spinigers
(although as discussed by Darbyshire 2014 it is not clear that these chaetae are
alike in all species). Gymnonereis is most similar to Tambalagamia and the two
have been combined by some authors, Gymnonereis being the senior synonym
(Pettibone 1970; Hylleberg and Nateewathana 1988).
Gymnonereis is a genus of seven species, predominantly occurring in the
southern hemisphere and the tropical Indo-Pacic and from shallow water (~
60 m or less). There is no published key to all species although several regional
keys exist (Hylleberg and Nateewathana 1988; Hutchings and Reid 1990).
Hediste Malmgren, 1867
Nereis (Hediste) Malmgren, 1867.
Type species. Nereis diversicolor Müller, 1776.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=146968.
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Sources. Sato and Nakashima (2003).
Diagnosis. Neurochaetae dorsal fascicle simple chaetae (fused falcigers)
present; palpophore massive subconical, attened (palpostyle is minute by
comparison) (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore massive subconical, attened (palpostyle is minute
by comparison). Palpophore surface with a single transverse groove (palpo-
phores well developed). Tentacular belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Area I conical paragnaths
present; II conical paragnaths present; III conical paragnaths present; III rod-
like paragnaths absent; IV paragnaths present; IV conical paragnaths present;
IV rod-like paragnaths absent. Oral ring papillae absent. Oral ring paragnaths
present; with Areas V, VI, and VII-VIII discrete; on Areas V and VI form distinct
groups. Area V conical paragnaths absent. Area VI paragnaths present; parag-
naths arranged in a roughly circular group, or in lines or arcs; conical parag-
naths present; smooth bars absent. Area VII-VIII paragnaths present; conical
paragnaths present; conical paragnaths arranged in one or more irregular lines
forming a continuous band; conical paragnaths similar in size, or irregular mix
of large and small paragnaths in a single band; rod-shaped paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; not markedly reduced on posterior
chaetigers. Prechaetal notopodial lobe present; smaller than dorsal notopodial
ligule on anterior chaetigers, usually reduced or absent posteriorly; restricted
to a limited number of anterior chaetigers. Notopodial acicular process absent.
Dorsal cirrus not sub-terminally attached to dorsal notopodial ligule on poste-
rior chaetigers; not terminally attached to dorsal notopodial ligule on posterior
chaetigers; not terminally attached throughout all chaetigers.
Neuropodial postchaetal lobe absent, or present; projecting beyond end of
the acicular ligule; restricted to anterior chaetigers; digitiform. Ventral neuropo-
dial ligule of anterior chaetigers present. Ventral neuropodial ligule of anterior
chaetigers approx. as long as acicular neuropodial ligule. Ventral neuropodial
ligule on posterior chaetigers present. Ventral neuropodial ligule on posterior
chaetigers similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spini-
gers present. Neurochaetae dorsal fascicle: heterogomph spinigers absent; ho-
mogomph spinigers present; heterogomph falcigers in anterior chaetigers pres-
ent; on posterior chaetigers present; blades serrated; simple chaetae (fused
falcigers) present. Neurochaetae ventral fascicle: heterogomph spinigers pres-
ent or absent; homogomph spinigers absent; homogomph falcigers present or
absent; heterogomph falcigers present; anterior chaetigers heterogomph fal-
cigers with long blades absent; anterior chaetigers heterogomph falcigers with
extra-long blades present; anterior chaetigers heterogomph falcigers with short
blades absent; posterior chaetigers heterogomph falcigers with long blades ab-
sent; posterior chaetigers heterogomph falcigers with extra-long blades pres-
ent; posterior chaetigers heterogomph falcigers with short blades absent; het-
erogomph falcigers blade lacking distinct tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. Hediste species are characterised by the “simple” neuropodial fal-
cigers (with fused articulation) which are present in posterior chaetigers and by
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having paragnaths on both rings of the pharynx. The most recent taxonomic treat-
ments are Sato and Nakashima (2003) and Teixeira et al. (2022a) who described
a total of four new species, broadened the generic diagnosis, and demonstrated
the power of morphometric methods to discriminate cryptic species.
Hediste is a genus of estuarine nereidids which occur in the northern hemi-
sphere. Seven species of Hediste are currently described but despite recent
publications, the most widespread species, H. diversicolor (O.F. Müller, 1776)
still contains cryptic species not yet described (Tosuji et al. 2018; Teixeira et al.
2022a). A key to Asian species of Hediste is provided by Sato and Nakashima
(2003) and Teixeira et al. (2022a) provide a key to European species.
Imajimainereis de León-González & Solis-Weiss, 2000
Type species. Imajimainereis pacica de León-González & Solís-Weiss, 2000.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=325837.
Sources. de León-González and Solís-Weiss (2000).
Diagnosis. Oral ring paragnaths present; oral ring papillae present; neuro-
chaetae dorsal fascicle heterogomph spinigers present (minimal diagnosis).
Neurochaetae dorsal fascicle heterogomph falcigers in anterior chaetigers ab-
sent; Area VI papillae absent; palpophore barrel-shaped, approximately equal
width from base to palpostyle (not overly large compared with palpostyle) (sec-
ondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Tentacular belt
greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Area I conical paragnaths
present; II conical paragnaths present; III conical paragnaths present; III rod-
like paragnaths absent; IV paragnaths present; IV conical paragnaths present; IV
rod-like paragnaths absent. Oral ring papillae present. Oral ring papillae arrange-
ment solitary. Area V papillae absent; VI papillae absent; VII-VIII papillae pres-
ent. Oral ring paragnaths present; with Areas V, VI, and VII-VIII discrete; on Areas
V and VI form distinct groups. Area V conical paragnaths absent. Area VI parag-
naths present; paragnaths arranged in a roughly circular group; conical parag-
naths present; smooth bars absent. Areas VII-VIII paragnaths present; conical
paragnaths present; conical paragnaths arranged in one or more irregular lines
forming a continuous band; conical paragnaths similar in size, or irregular mix
of large and small paragnaths in a single band; rod-shaped paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; not markedly reduced on posterior
chaetigers. Prechaetal notopodial lobe present; smaller than dorsal notopodial
ligule on anterior chaetigers, usually reduced or absent posteriorly. Dorsal cirrus
not sub-terminally attached to dorsal notopodial ligule on posterior chaetigers;
not terminally attached to dorsal notopodial ligule on posterior chaetigers; not
terminally attached throughout all chaetigers.
Neuropodial postchaetal lobe present. Ventral neuropodial ligule of anteri-
or chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx.
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as long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior
chaetigers present. Ventral neuropodial ligule on posterior chaetigers similar to
length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers present;
homogomph spinigers present; heterogomph falcigers in anterior chaetigers
absent; on posterior chaetigers present; blades serrated; blades with teeth only
slightly longer proximally than distally. Neurochaetae ventral fascicle: hetero-
gomph spinigers present; homogomph spinigers present; heterogomph fal-
cigers present; anterior chaetigers heterogomph falcigers with long blades ab-
sent; anterior chaetigers heterogomph falcigers with extra-long blades absent;
anterior chaetigers heterogomph falcigers with short blades absent; posterior
chaetigers heterogomph falcigers with long blades absent; posterior chaeti-
gers heterogomph falcigers with extra-long blades present; posterior chaeti-
gers heterogomph falcigers with short blades absent.
Remarks. Imajimainereis contains a single species, I. pacica de León-
González & Solís-Weiss, 2000, which differs from all other Nereididae by having
both papillae and paragnaths on the oral ring and neurochaetae including het-
erogomph spinigers.
Imajimainereis is recorded from the Gulf of California, eastern Pacic Ocean
(de León-González and Solís-Weiss 2000).
Kainonereis Chamberlin, 1919
Type species. Kainonereis alata Chamberlin, 1919.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324852.
Sources. Conde-Vela et al. (2018); Chamberlin (1919).
Diagnosis. Dorsal cirrophores of chaetigers 5–7 of epitokes modied into
attened elytriform discs (minimal diagnosis). Notochaetae homogomph
falcigers present; maxillary ring paragnaths absent; oral ring paragnaths
absent; dorsal notopodial ligule not markedly reduced on posterior chaetigers
(secondary diagnosis).
Description. Palps anteriorly directed, or ventrally directed. Palpophore bar-
rel-shaped, approximately equal width from base to palpostyle (not overly large
compared with palpostyle). Prostomium the antennae are separate but some-
times basally fused in male epitokes. Tentacular cirri articulated.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring paragnaths absent.
Dorsal notopodial ligule commences chaetiger 3, or chaetiger 4 (from chaeti-
ger 4 in males, 3 in females); not markedly elongate on posterior chaetigers; not
markedly reduced on posterior chaetigers. Prechaetal notopodial lobe present
(subconical to digitate in atokes, rounded in epitokes). Dorsal cirrus not sub-ter-
minally attached to dorsal notopodial ligule on posterior chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe pres-
ent; present throughout all chaetigers. Ventral neuropodial ligule of anterior
chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx.
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as long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior
chaetigers present.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph
spinigers present; homogomph falcigers present (in males, on anterior chae-
tigers); homogomph falcigers with multidentate blade with two or more small
lateral teeth, rst and subsequent lateral teeth much smaller than terminal
tooth present. Neurochaetae dorsal fascicle: heterogomph spinigers absent;
homogomph spinigers present; heterogomph falcigers in anterior chaeti-
gers present. Neurochaetae ventral fascicle: heterogomph spinigers present;
homogomph spinigers absent; heterogomph falcigers present; falcigers blade
bowed, with convex margin.
Pygidium bilobate. Anal cirri form cirriform or conical.
Epitokes. Dorsal cirrophores of chaetigers 5–7 of epitokes modied into at-
tened elytriform discs. Natatory epitokal modications in males commence chae-
tiger 15. Natatory epitokal modications in females commence chaetiger 15.
Remarks. Kainonereis was originally described for an epitokous specimen in
which dorsal cirri of chaetigers 5–7 were expanded into elytra-like structures.
Unless epitokes are available Kainonereis is not separable from Nicon and
Websterinereis (this does not imply that Kainonereis is invalid). A revision by
Conde-Vela et al. (2018) redened the genus and included atokous characters;
ve species are now recognised and epitokes can be identied using the key of
Conde-Vela et al. (2018).
Kinberginereis Pettibone, 1971
Type species. Nereis (Leptonereis) inermis Hoagland, 1920.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=843657.
Sources. Pettibone (1971); Bakken et al. (2022).
Diagnosis. Neurochaetae ventral fascicle heterogomph spinigers in anteri-
or chaetigers with blades coarsely serrated proximally; oral ring papillae pres-
ent; maxillary ring of pharynx with papillae absent (minimal diagnosis). Pros-
tomium anterior margin indented; prechaetal notopodial lobe approximately
equal to length of dorsal notopodial ligule at least on anterior chaetigers (thus
notopodium of three similar sized ligules/lobes); antennae form cirriform
(usually extending to or past palpophore); maxillary ring paragnaths absent
(secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle) (elongate).
Prostomium anterior margin indented.
Jaws with dentate cutting edge, 20 teeth.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae present. Oral ring papillae number two in total; arrange-
ment solitary. Area V papillae absent; VI papillae present, one papilla (a single
eshy nob on each side); VII-VIII papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule present; markedly reduced on posterior chaetigers.
Prechaetal notopodial lobe present; approximately equal to length of dorsal no-
topodial ligule at least on anterior chaetigers (thus notopodium of three similar
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sized ligules/lobes); present on all chaetigers. Dorsal cirrus not sub-terminally
attached to dorsal notopodial ligule on posterior chaetigers.
Neuropodial prechaetal lobe present. Neuropodial postchaetal lobe present;
projecting beyond end of the acicular ligule; attened. Ventral neuropodial ligu-
le of anterior chaetigers present. Ventral neuropodial ligule of anterior chaeti-
gers approx. as long as acicular neuropodial ligule. Ventral neuropodial ligule
on posterior chaetigers present. Ventral neuropodial ligule on posterior chaeti-
gers similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph
spinigers present. Neurochaetae dorsal fascicle: heterogomph spinigers ab-
sent; homogomph spinigers present; heterogomph falcigers in anterior chae-
tigers absent; on posterior chaetigers absent. Neurochaetae ventral fascicle:
heterogomph spinigers present; spinigers in anterior chaetigers with blades
coarsely serrated proximally; homogomph spinigers absent; heterogomph
falcigers absent.
Remarks. The most recent taxonomic treatment of Kinberginereis is the orig-
inal description of Pettibone (1971). Kinberginereis is most similar to Kainone-
reis, atokes differing only in that Kinberginereis has an indented prostomium
but the prostomium of Kainonereis is entire. Epitokes of Kainonereis are distinc-
tive in having elytriform expansion of dorsal cirrophores of chaetigers 5–7 but
epitokes of Kinberginereis are unknown.
Kinberginereis includes a single species, K. inermis (Hoagland, 1920) de-
scribed from a single specimen from shallow water in the Philippines; the only
subsequent reports are unveried occurrence records now in the Smithsonian
National Museum of Natural History from the Gulf of Mexico.
Laeonereis Hartman, 1945
Type species. Nereis culveri Webster, 1879.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=181592.
Sources. Pettibone (1971); Conde-Vela (2021).
Diagnosis. Maxillary ring of pharynx with papillae in tufts (minimal diagnosis).
Dorsal notopodial ligule commences chaetiger 1; neurochaetae ventral fascicle
homogomph falcigers on posterior chaetigers present (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Prostomium
anterior margin indented; longitudinal groove present.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae present; in tufts. Maxillary ring parag-
naths absent. Oral ring papillae present. Oral ring papillae arrangement solitary.
Area V papillae absent; VI papillae present; VII-VIII papillae present or absent
(may be absent in juveniles). Oral ring paragnaths absent. Papillae triangular or
conical on Area VI, rounded on Areas VII-VIII.
Dorsal notopodial ligule present; commences chaetiger 1; not markedly elon-
gate on posterior chaetigers; not markedly broader on posterior chaetigers; not
markedly reduced on posterior chaetigers. Prechaetal notopodial lobe present;
smaller than dorsal notopodial ligule on anterior chaetigers, usually reduced or
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absent posteriorly; restricted to a limited number of anterior chaetigers. Notopodi-
al acicular process absent. Dorsal cirrus not sub-terminally attached to dorsal no-
topodial ligule on posterior chaetigers; not terminally attached to dorsal notopodi-
al ligule on posterior chaetigers; not terminally attached throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
projecting beyond end of the acicular ligule; restricted to anterior chaetigers.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodi-
al ligule of anterior chaetigers approx. as long as acicular neuropodial ligule.
Ventral neuropodial ligule on posterior chaetigers present. Ventral neuropodial
ligule on posterior chaetigers similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph
spinigers present. Neurochaetae dorsal fascicle: heterogomph spinigers ab-
sent; homogomph spinigers present; heterogomph falcigers in anterior chae-
tigers absent; on posterior chaetigers absent; homogomph falcigers in ante-
rior chaetigers present, or absent; on posterior chaetigers present, or absent.
Neurochaetae ventral fascicle: heterogomph spinigers absent; homogomph
spinigers present; heterogomph falcigers absent; homogomph falcigers on
posterior chaetigers present (with long blades).
Pygidium funnel-shaped, crenulated, or multi-incised, with ventral incision.
Anal cirri cirriform or conical.
Remarks. The description and diagnosis of Laeonereis here is derived from
the revision of Conde-Vela (2021) which is only slightly modied from that
of Pettibone (1971) who recognised a single species of Laeonereis. Simulta-
neously with the publication of the morphological revision of Laeonereis by
Conde-Vela (2021), Sampieri et al. (2021) published a molecular study of Laeo-
nereis (but with no morphological component) and revealed seven or nine mo-
lecular OTUs. It is tantalising that Sampieri et al. (2021) and Conde-Vela (2021)
discovered very similar species-level diversity from within the same geographic
range but frustrating that neither apparently was aware of the others’ research.
Currently eight species of Laeonereis are recognised, largely conned to the
Atlantic coasts of North and South America; they can be identied using the
key of Conde-Vela (2021).
Leonnates Kinberg, 1865
Nereis (Leonnates) auctt.
Laevispinereis He & Wu, 1989.
Type species. Leonnates indicus Kinberg, 1865.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129374.
Sources. Qiu and Qian (2000); Villalobos-Guerrero et al. (2022a).
Diagnosis. Oral ring papillae present; maxillary ring paragnaths present; oral
ring paragnaths absent; ventral neuropodial ligule on posterior chaetigers similar
to length of acicular neuropodial ligule; neurochaetae dorsal fascicle homogomph
spinigers present (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from base
to palpostyle (not overly large compared with palpostyle), or massive subconical,
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attened (palpostyle is minute by comparison). Palpophore surface with a single
transverse groove (palpophores well developed). Prostomium anterior margin
entire or indented (indented only in L. persicus and L. stephensoni); longitudinal
groove present; anterior region sub-quadrangular or sub-rectangular. Tentacular
belt greater than length of chaetiger 1.
Oesophageal caeca absent.
Jaws with smooth or slightly crenulate cutting edge or with dentate cutting edge.
Maxillary ring of pharynx with papillae present, or absent; solitary. Maxillary ring
paragnaths present. Area I conical paragnaths present, or absent; II conical parag-
naths present; III conical paragnaths present, or absent; III rod-like paragnaths
absent; IV paragnaths present; IV conical paragnaths present; IV smooth bar-like
paragnaths present, or absent; IV rod-like paragnaths absent. Oral ring papillae
present. Oral ring papillae arrangement solitary. Area V papillae present, or ab-
sent; VI papillae present; VII-VIII papillae present. Oral ring paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; not markedly reduced on poste-
rior chaetigers. Prechaetal notopodial lobe present; smaller than dorsal no-
topodial ligule on anterior chaetigers, usually reduced or absent posteriorly, or
approximately equal to length of dorsal notopodial ligule at least on anterior
chaetigers (thus notopodium of three similarly sized ligules/lobes); present
on all chaetigers, or restricted to a limited number of anterior chaetigers. No-
topodial acicular process absent. Dorsal cirrus not sub-terminally attached
to dorsal notopodial ligule on posterior chaetigers; not terminally attached
to dorsal notopodial ligule on posterior chaetigers; not terminally attached
throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
projecting beyond end of the acicular ligule; present throughout all chaetigers
or restricted to anterior chaetigers; digitiform. Ventral neuropodial ligule of
anterior chaetigers present. Ventral neuropodial ligule of anterior chaetigers
approx. as long as acicular neuropodial ligule. Ventral neuropodial ligule on
posterior chaetigers present. Ventral neuropodial ligule on posterior chaetigers
similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph
spinigers present; homogomph falcigers present, or absent. Neurochaetae
dorsal fascicle: heterogomph spinigers present, or absent (present in L. fuji-
anensis); homogomph spinigers present; sesquigomph spinigers present, or
absent (present in L. fujianensis); sesquigomph falcigers present, or absent;
heterogomph falcigers in anterior chaetigers present, or absent; on posteri-
or chaetigers present, or absent; homogomph falcigers in anterior chaetigers
present, or absent; on posterior chaetigers present, or absent. Neurochaetae
ventral fascicle: sesquigomph falcigers present, or absent; blade with a single
distal tooth; heterogomph spinigers present, or absent; homogomph spinigers
present, or absent; sesquigomph spinigers present, or absent; heterogomph
falcigers present, or absent; falcigers blade bowed, with convex margin; hetero-
gomph falcigers blade lacking distinct tendon on terminal tooth; homogomph
falcigers in anterior chaetigers present, or absent; on posterior chaetigers
present, or absent. Ventral fascicle neuropodial falcigers apparently vary con-
siderably between species.
Anal cirri form cirriform or conical.
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Remarks. The current description and diagnosis follow Qiu and Qian (2000)
and emendments by Villalobos-Guerrero et al. (2022a). Original descriptions
sometimes report the presence of sesquigomph falcigers and spinigers but as
noted by Qiu and Qian (2000) some of these interpretations are inconsistent,
with the same chaetal forms being given different names by some authors.
However Qiu and Qian (2000) also do not interpret these terms consistently:
they do not use the term sesquigomph yet their gures 3B and 3E (Leonnates
indicus Kinberg, 1865), 5E (L. nierstraszi Horst, 1924), 7B (L. decipiens Fauvel,
1929), 9D (L. persicus Wesenberg-Lund, 1949, and 14D (L. crinitus Hutchings
& Reid, 1991, albeit damaged) all show sesquigomph articulation as accepted
by other authors, e.g. Villalobos-Guerrero et al. (2022a: g. 12i, j; Parasetia ir-
ritabilis (Webster, 1879)), Bakken et al. (2022: gs 7.13.3.3.3: C, 7.13.3.3.4: C),
de León-González and Salazar-Vallejo (2003: g. 1E, F) (Leonnates crosnieri de
León-González & Salazar-Vallejo, 2003).
Leonnates includes 13 species with the greatest diversity in the tropical In-
do-Pacic. Qiu and Qian (2000) provide a key to the seven species known at
that time.
Leptonereis Kinberg, 1865
Nereis (Leptonereis) auctt.
Type species. Leptonereis laevis Kinberg, 1865.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=152401.
Sources. Hartman 1945; Pettibone 1971.
Diagnosis. Dorsal cirrus terminally attached to dorsal notopodial ligule on
posterior chaetigers; maxillary ring paragnaths absent (minimal diagnosis).
Dorsal notopodial ligule markedly broader on posterior chaetigers; prostomium
anterior margin entire; maxillary ring of pharynx with P-bar paragnaths absent
(secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle).
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule present; markedly elongate on posterior chaetigers;
markedly broader on posterior chaetigers; not markedly reduced on posterior
chaetigers. Dorsal cirrus not sub-terminally attached to dorsal notopodial ligule
on posterior chaetigers; terminally attached to dorsal notopodial ligule on pos-
terior chaetigers; not terminally attached throughout all chaetigers.
Neuropodial postchaetal lobe absent. Ventral neuropodial ligule of anterior
chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx.
as long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior
chaetigers present. Ventral neuropodial ligule on posterior chaetigers similar to
length of acicular neuropodial ligule.
Notochaetae: homogomph spinigers present. Neurochaetae homogomph
and heterogomph spinigers and heterogomph falcigers, but their distribution in
dorsal and ventral fascicles is unknown.
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Remarks. The description of Leptonereis given here follows the most recent
treatment (Pettibone 1971) which in turn was based on new descriptions and
gures of the type by Kinberg (1910) and Hartman (1945). However, many char-
acters including articulation of the chaetae remain unveried.
Leptonereis includes a single species, L. laevis Kinberg, 1865, based on a
single specimen from Guayaquil, Ecuador and now recorded from tropical east
Pacic coasts of North and South America.
Lycastonereis Rao, 1981
Type species. Lycastonereis indica Rao, 1981.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324857.
Sources. Rao (1981); Conde-Vela (2019a).
Diagnosis. Tentacular cirri three pairs; palpophore surface with a single trans-
verse groove (palpophores well developed) (minimal diagnosis). Neurochaetae
dorsal fascicle homogomph falcigers on posterior chaetigers present; maxillary
ring paragnaths absent; prostomium anterior margin entire (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore
surface with a single transverse groove (palpophores well developed). Prosto-
mium anterior margin entire. Tentacular belt greater than length of chaetiger 1.
Tentacular cirri three pairs.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae present. Maxillary ring paragnaths ab-
sent. Oral ring papillae present. Oral ring papillae arrangement solitary. Area
V papillae absent; VI papillae present; VII-VIII papillae present, arranged in a
single row. Oral ring paragnaths absent.
Dorsal notopodial ligule markedly reduced or absent on posterior chaeti-
gers. Prechaetal notopodial lobe present; restricted to a limited number of an-
terior chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
not projecting beyond end of the acicular ligule; digitiform. Ventral neuropodi-
al ligule of anterior chaetigers present. Ventral neuropodial ligule of anterior
chaetigers approx. as long as acicular neuropodial ligule. Ventral neuropodial
ligule on posterior chaetigers present. Ventral neuropodial ligule on posterior
chaetigers short, up to half length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph
spinigers present. Neurochaetae dorsal fascicle: heterogomph spinigers ab-
sent; homogomph spinigers present; dorsal fascicle heterogomph falcigers
in anterior chaetigers absent; on posterior chaetigers absent; dorsal fascicle
homogomph falcigers in anterior chaetigers present; on posterior chaetigers
present; ventral fascicle heterogomph spinigers absent; homogomph spinigers
present; sesquigomph spinigers present. Neurochaetae ventral fascicle: het-
erogomph falcigers absent; homogomph falcigers in anterior chaetigers pres-
ent; on posterior chaetigers present.
Remarks. This easily diagnosed genus from estuaries in India includes a
single species. Conde-Vela (2019a) provides a redescription based on non-type
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material which is topotypic and shares the unusual morphological characters
of the original description including the presence of only three pairs of tentac-
ular cirri. Conde-Vela (2019a) also claried the surname of the author, which is
Rao, not ‘Nageswara-Rao’ or ‘Nageswara Rao’ as stated in much of the litera-
ture. Although the double surname is a more precise authority name, we follow
Conde-Vela (2019a) because Rao appears to be an uncommon name among
polychaete taxon authors and thus not easily confused.
Micronereides Day, 1963
Type species. Micronereides capensis Day, 1963.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324861.
Sources. Day (1963).
Diagnosis. Tentacular belt represented by two distinct segments each car-
rying a pair of tentacular cirri (minimal diagnosis). Dorsal notopodial ligule
absent; neurochaetae ventral fascicle sesquigomph spinigers present (sec-
ondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Eyes absent.
Prostomium with eyes, if not absent, indistinct and likely to be missed. Tentac-
ular belt equal to or less than length of chaetiger 1; represented by two distinct
segments each carrying a pair of tentacular cirri.
Jaws with dentate cutting edge, seven teeth.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule absent. Prechaetal notopodial lobe absent. Notopo-
dial acicular process absent.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe absent.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodial li-
gule of anterior chaetigers short, up to half length of acicular neuropodial ligule.
Ventral neuropodial ligule on posterior chaetigers present. Ventral neuropodial
ligule on posterior chaetigers similar to length of acicular neuropodial ligule.
Dorsal notopodial ligule elongate, exceeding length of dorsal cirrus.
Notochaetae: homogomph spinigers present. Neurochaetae dorsal
fascicle: heterogomph spinigers absent; homogomph spinigers present;
heterogomph falcigers in anterior chaetigers absent; on posterior chaetigers
absent; ventral fascicle heterogomph spinigers absent; homogomph
spinigers present; sesquigomph spinigers present (possibly, chaetae
needre-examination).
Remarks. Micronereides was erected to contain M. capensis Day, 1963 a
small nereidid lacking pharyngeal papillae or paragnaths and in which tentacu-
lar cirri arise from two distinct anterior segments (unique among Nereididae). A
revised diagnosis was provided by Banse (1977) including the observation that
accessory ventral cirri are present on anterior segments thus placing the genus
in Gymnonereidinae.
The genus is still only known from a single species, M. capensis, recorded
from shelf depths in the South Atlantic Ocean.
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Micronereis Claparède, 1863
Notophycus Knox & Cameron, 1970.
Phyllodocella Fauchald & Belman, 1972.
Quadricirra Banse, 1977.
Type species. Micronereis variegata Claparède, 1863.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129375.
Sources. Paxton (1983).
Diagnosis. Palpostyles absent (palps undivided, minute) (minimal diagno-
sis). Maxillary ring of pharynx undivided (secondary diagnosis).
Description. Antennae absent. Palps ventrally directed. Palpophore surface
with a single transverse groove (palpophores well developed); palpostyles ab-
sent (palps undivided, minute).
Jaws with dentate cutting edge.
Maxillary ring of pharynx undivided.
Maxillary ring of pharynx with papillae absent; undivided maxillary ring with
two paragnaths in total. Oral ring papillae absent. Oral ring paragnaths present;
on Areas V and VI not recognisably distinct. Crown-shaped oral ring paragnaths
present. Area V conical paragnaths absent.
Dorsal notopodial ligule absent. Prechaetal notopodial lobe absent. Notopo-
dial acicular process absent. Acicular notopodial ligule absent.
Neuropodial postchaetal lobe absent. Ventral neuropodial ligule of anterior
chaetigers absent. Ventral neuropodial ligule on posterior chaetigers absent.
Notoaciculae on chaetigers 1 and 2 absent (only conrmed as yet for M.
bansei). Notochaetae: homogomph spinigers present; homogomph falcigers
present or absent; homogomph falcigers with multidentate blade with two
or more small lateral teeth, rst and subsequent lateral teeth much small-
er than terminal tooth present. Neurochaetae dorsal fascicle: heterogomph
spinigers absent; homogomph spinigers present; heterogomph falcigers
in anterior chaetigers absent; homogomph falcigers in anterior chaetigers
present; on posterior chaetigers present. Neurochaetae ventral fascicle: het-
erogomph spinigers absent; homogomph spinigers present; heterogomph
falcigers absent.
Anal cirri form cirriform or conical.
Remarks. Micronereis is a genus of small nereidids generally associated with
algal turfs in intertidal and shallow (to ~ 30 m) marine waters. Micronereis spe-
cies differ from other Nereididae in lacking antennae and having a pharynx that
is not fully eversible. They are sexually dimorphic and males have distinctive
neurochaetae that function as copulatory hooks not found in other Nereididae.
Micronereis currently includes ten accepted species which collectively have
a wide global distribution. Paxton (1983) revised the genus and included a key
to males but three more species have since been recognised.
Namalycastis Hartman, 1959
Type species. Lycastis abiuma Grube, 1872.
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WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129376.
Sources. Glasby (1999).
Diagnosis. Palpophore surface without grooves or striae (palps short, com-
pact); antennae form subconical (shorter than palpophore) (minimal diagno-
sis). Prostomium anterior margin indented (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore
surface without grooves or striae (palps short, compact) or with a single trans-
verse groove (palpophores well developed); palpostyles spherical. Prostomium
anterior margin indented; longitudinal groove present. Tentacular belt equal to
or less than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae absent. Oral ring paragnaths absent.
Notopodium strongly reduced, without distinct lobes or ligules. Dorsal cirrus
arising from basal cirrophore (weakly developed; only on anterior chaetigers).
Neuropodial postchaetal lobe absent. Ventral neuropodial ligule of anterior
chaetigers absent. Ventral neuropodial ligule on posterior chaetigers absent.
Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph spin-
igers absent; sesquigomph spinigers present, or absent. Neurochaetae dorsal
fascicle: heterogomph spinigers present (rarely), or absent; homogomph spini-
gers absent; sesquigomph spinigers present; heterogomph falcigers in anterior
chaetigers present, or absent (rarely); on posterior chaetigers present, or absent;
blades smooth, or serrated; blades with teeth only slightly longer proximally than
distally. Neurochaetae ventral fascicle: heterogomph spinigers present; spini-
gers in anterior chaetigers with blades evenly serrated throughout, or coarsely
serrated proximally (rarely); on posterior chaetigers with blades nely serrated
proximally, or coarsely serrated proximally; homogomph spinigers absent; het-
erogomph falcigers present, or absent (rarely); anterior chaetigers heterogomph
falcigers with long blades absent; anterior chaetigers heterogomph falcigers with
extra-long blades present; anterior chaetigers heterogomph falcigers with short
blades absent; posterior chaetigers heterogomph falcigers with long blades ab-
sent; posterior chaetigers heterogomph falcigers with extra-long blades present;
posterior chaetigers heterogomph falcigers with short blades absent.
Pygidium with three incisions marking lateral and dorsal lobes. Anal cirri
form cirriform or conical, or attened, resembling posterior dorsal cirri.
Reproductive characters. Oocyte spherical.
Remarks. Namalycastis currently includes 33 accepted species recorded
mainly from intertidal and supralittoral areas, including freshwater, of the trop-
ics and subtropics. Together with sister-group Namanereis, they are one of
only a few polychaetes to be found in association with riparian vegetation.
Because they have an unadorned pharynx and a simplied parapodia, distin-
guishing species relies heavily on differences in chaetae, form of sensory or-
gans of the head, and pigmentation patterns in living specimens. The modern
concept of the subfamily and genus was introduced by Hartman (1959) and
later reviewed by Glasby (1999), who included a key to all known species at
the time. Since Glasby (1999) there have been ve species described: Nam-
alycastis caetensis Alves & Santos, 2016, Namalycastis glasbyi Fernando &
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Rajasekaran, 2007, Namalycastis jaya Magesh, Kvist & Glasby, 2012, Nama-
lycastis occulta Conde-Vela, 2013 and Namalycastis rhodochorde Glasby, Mi-
ura, Nishi & Junardi, 2007; however, Namalycastis occulta Conde-Vela, 2013
is now accepted as Namanereis occulta (Conde-Vela, 2013). Magesh et al.
(2013) provided a key to Indian species and Conde-Vela (2013) provided a key
to Caribbean species.
Namanereis Chamberlin, 1919
Cryptonereis Gibbs, 1971.
Lycastella Feuerborn, 1932.
Lycastilla Solís-Weiss & Espinasa, 1991.
Lycastoides Jakubova, 1930.
Lycastopsis Augener, 1922.
Type species. Lycastis quadraticeps Blanchard in Gay, 1849.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129377.
Sources. Glasby (1999).
Diagnosis. Palpophore surface without grooves or striae (palps short, com-
pact); prostomium anterior margin entire (minimal diagnosis). Palpostyles
spherical; dorsal cirrus simple, lacking basal cirrophore (secondary diagnosis).
Description. Antennae present, or absent (rarely). Palpophore barrel-shaped,
approximately equal width from base to palpostyle (not overly large compared
with palpostyle). Palpophore surface without grooves or striae (most species;
palps short, compact) or with a single transverse groove (palpophores well de-
veloped); palpostyles spherical. Eyes present, or absent. Tentacular belt equal
to or less than length of chaetiger 1. Tentacular cirri four pairs, or three pairs.
Jaws forms with a crenulate cutting edge have 2 teeth proximally, with
smooth or slightly crenulate cutting edge or with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae absent. Oral ring paragnaths absent.
Notopodium strongly reduced, without distinct lobes or ligules.
Neuropodial postchaetal lobe absent. Ventral neuropodial ligule of anterior
chaetigers absent. Ventral neuropodial ligule on posterior chaetigers absent.
Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph
spinigers absent; sesquigomph spinigers present (rarely), or absent. Neuro-
chaetae dorsal fascicle: heterogomph spinigers present (rarely), or absent;
homogomph spinigers absent; sesquigomph spinigers present, or absent;
heterogomph falcigers in anterior chaetigers present; on posterior chaetigers
present; blades serrated; blades with teeth only slightly longer proximally than
distally, or much longer proximally than distally. Neurochaetae ventral fascicle:
heterogomph spinigers present (rarely), or absent; spinigers in anterior chae-
tigers with blades evenly serrated throughout; on posterior chaetigers with
blades nely serrated proximally; homogomph spinigers absent; heterogomph
falcigers present (some forms with very long blades = pseudospinigers); ante-
rior chaetigers heterogomph falcigers with long blades present; anterior chaeti-
gers heterogomph falcigers with extra-long blades present; anterior chaetigers
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heterogomph falcigers with short blades absent; posterior chaetigers hetero-
gomph falcigers with long blades present, or absent; posterior chaetigers het-
erogomph falcigers with extra-long blades present, or absent; posterior chaeti-
gers heterogomph falcigers with short blades absent.
Pygidium with three incisions marking lateral and dorsal lobes. Anal cirri form
cirriform or conical, or short, stout and appearing as an extension of the pygidium.
Reproductive characters. Oocyte spherical (rarely), or ovoid.
Remarks. Namanereis currently includes 27 accepted species recorded
mainly from intertidal, supralittoral and terrestrial areas, including the fresh-
waters of streams, caves, and underground aquifers. Although mainly found in
the tropics and subtropics one species, Namanereis quadraticeps (Blanchard
in Gay 1849), has a circum-subantarctic/temperate distribution. Together with
sister-group Namalycastis, they are one of only a few polychaetes to be found
in association with riparian vegetation. Because they have an unadorned
pharynx and a simplied parapodia, distinguishing species relies heavily on
differences in chaetae and form of sensory organs of the head. The modern
concept of the subfamily and genus was introduced by Hartman (1959) and
reviewed by Glasby (1999), the latter who included a key to all known species
at the time. Since Glasby (1999) there have been seven species described: Na-
manereis canariarum Núñez, Glasby & Naranjo, 2020, Namanereis christopheri
Conde-Vela, 2017, Namanereis gesae Fiege & Van Damme, 2002, Namanereis
llanetensis Núñez, Glasby & Naranjo, 2020, Namanereis occulta (Conde-Vela,
2013), Namanereis pilbarensis Glasby, Fiege & Van Damme, 2014, and Nama-
nereis socotrensis Glasby, Fiege & Van Damme, 2014, making this genus one
of the most studied in the last 20 or so years. As noted by Alves et al. (2018)
in a morphological phylogenetic study of the subfamily, Lycastoides alticola
Johnson, 1903 is also part of the Namanereis clade, but the species cannot
take the name Namanereis, as Lycastoides is the senior genus (Read and Fau-
chald 2023). Conde-Vela (2017) provides an updated key to Namanereis spe-
cies of the World.
Neanthes Kinberg, 1865
Nereis (Neanthes) auctt.
Nereis (Neanthioides) Rioja, 1918.
Praxithea Malmgren, 1867.
Type species. Neanthes vaalii Kinberg, 1865.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129378.
Sources. Bakken et al. (2022).
Diagnosis. Maxillary ring paragnaths present; neurochaetae dorsal fascicle
heterogomph falcigers in anterior chaetigers present; dorsal notopodial ligule
not markedly broader on posterior chaetigers; oral ring papillae absent; noto-
chaetae homogomph falcigers absent; notochaetae sesquigomph falcigers
absent; neurochaetae dorsal fascicle simple chaetae (fused falcigers) absent;
Area VI smooth bars absent; notoaciculae on chaetigers 1 and 2 absent (mini-
mal diagnosis; secondary diagnosis not attained).
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Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle), or massive
subconical, attened (palpostyle is minute by comparison) (rarely). Palpo-
phore surface without grooves or striae or with a single transverse groove
(palpophores well developed) or with several oblique grooves or striae (palpo-
phores well developed). Eyes present, or absent. Tentacular belt greater than
length of chaetiger 1.
Oesophageal caeca present, or absent.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present; II conical paragnaths present, or
absent; III conical paragnaths present, or absent; III rod-like paragnaths absent;
IV paragnaths present, or absent; IV conical paragnaths present, or absent; IV
smooth bar-like paragnaths present, or absent; IV rod-like paragnaths absent.
Oral ring papillae absent. Oral ring paragnaths present, or absent; with Areas V,
VI, and VII-VIII discrete, or comprising a continuous ring dorsally and ventrally,
discrete groups not recognisable; on Areas V and VI form distinct groups, or
not recognisably distinct. Area V conical paragnaths present, or absent. Area VI
paragnaths present, or absent; paragnaths arranged in a roughly circular group,
or in lines or arcs; conical paragnaths present; smooth bars absent. Areas VII-
VIII paragnaths present, or absent; conical paragnaths present; conical parag-
naths arranged in one or more irregular lines forming a continuous band; coni-
cal paragnaths similar in size, or irregular mix of large and small paragnaths in
a single band, or differentiated, with a separate band of minute paragnaths also
present; rod-shaped paragnaths absent.
Dorsal notopodial ligule markedly elongate on anterior chaetigers, or not
markedly elongate on anterior chaetigers; markedly elongate on posterior chae-
tigers, or not markedly elongate on posterior chaetigers; not markedly broad-
er on posterior chaetigers; markedly reduced on posterior chaetigers, or not
markedly reduced on posterior chaetigers. Prechaetal notopodial lobe present,
or absent; smaller than dorsal notopodial ligule on anterior chaetigers, usually
reduced or absent posteriorly, or approximately equal to length of dorsal no-
topodial ligule at least on anterior chaetigers (thus notopodium of three similar
sized ligules/lobes); present on all chaetigers, or restricted to a limited number
of anterior chaetigers. Notopodial acicular process present, or absent; reducing
in size posteriorly, last present on chaetiger 5–25. Dorsal cirrus sub-terminally
attached to dorsal margin of dorsal notopodial ligule on posterior chaetigers, or
not sub-terminally attached to dorsal notopodial ligule on posterior chaetigers;
not terminally attached to dorsal notopodial ligule on posterior chaetigers; not
terminally attached throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe absent,
or present; projecting beyond end of the acicular ligule, or not projecting be-
yond end of the acicular ligule; present throughout all chaetigers, or restricted
to anterior chaetigers; digitiform. Ventral neuropodial ligule of anterior chaeti-
gers present. Ventral neuropodial ligule of anterior chaetigers approx. as long
as acicular neuropodial ligule, or short, up to half length of acicular neuropodi-
al ligule. Ventral neuropodial ligule on posterior chaetigers present, or absent.
Ventral neuropodial ligule on posterior chaetigers similar to length of acicular
neuropodial ligule, or short, up to half length of acicular neuropodial ligule.
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Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers present,
or absent; homogomph spinigers present; heterogomph falcigers in anterior
chaetigers present; on posterior chaetigers present, or absent; blades serrated.
Neurochaetae ventral fascicle: heterogomph spinigers present, or absent; ho-
mogomph spinigers present, or absent; heterogomph falcigers present; anterior
chaetigers heterogomph falcigers with long blades present, or absent; anterior
chaetigers heterogomph falcigers with extra-long blades present, or absent; an-
terior chaetigers heterogomph falcigers with short blades present, or absent;
posterior chaetigers heterogomph falcigers with long blades present, or absent;
posterior chaetigers heterogomph falcigers with extra-long blades present, or
absent; posterior chaetigers heterogomph falcigers with short blades present, or
absent; heterogomph falcigers blade lacking distinct tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. Neanthes, even after removing some species to Alitta and Pseu-
donereis, was found by Bakken and Wilson (2005) to contain morphologically
dissimilar species. Our diagnosis here compounds the problem since the de-
scription is expanded to include species with variable palpophore morphology
(N. gisserana (Horst, 1924) and N. glandicincta (Southern, 1921)) and with elon-
gate dorsal notopodial lobe on all chaetigers (N. articulata Knox, 1960, N. cruci-
fera (Grube, 1878), and N. mossambica Day, 1957) or only on posterior chaeti-
gers (N. mancorae Berkeley & Berkeley, 1961 and N. noodti Hartmann-Schröder,
1962). Furthermore, Neanthes includes a subset of species having well-devel-
oped prechaetal notopodial lobes, giving the notopodia a tri-lobed appearance,
which differs from the majority of bilobed species (Bakken 2006). However,
the genus must still comprise several unrelated groups. Neanthes currently in-
cludes 88 species. There are no comprehensive keys or identication guides
but there are several tabular comparisons of subsets of species, for example
Asian species (Hsueh 2019a; Villalobos-Guerrero and Idris 2021) and deep-sea
species (Shimabukuro et al. 2017).
Nectoneanthes Imajima, 1972
Type species. Nereis (Alitta) oxypoda Marenzeller, 1879.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324862.
Sources. Sato (2013).
Diagnosis. Dorsal notopodial ligule markedly broader on posterior chaetigers;
notochaetae sesquigomph spinigers present (minimal diagnosis). Palpophore
massive subconical, attened (palpostyle is minute by comparison); neurochae-
tae dorsal fascicle heterogomph spinigers present (secondary diagnosis).
Description. Palpophore massive subconical, attened (palpostyle is minute
by comparison).
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Area I conical paragnaths
present; II conical paragnaths present; III conical paragnaths present; III rod-like
paragnaths absent; IV paragnaths present; IV conical paragnaths present; IV
rod-like paragnaths absent. Oral ring paragnaths present; with Areas V, VI and
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VII-VIII discrete; on Areas V and VI form distinct groups. Area V conical parag-
naths present. Area VI paragnaths present; paragnaths arranged in a roughly
circular group; conical paragnaths present; smooth bars absent. Areas VII-VIII
paragnaths present; conical paragnaths present; conical paragnaths arranged
in one or more irregular lines forming a continuous band; conical paragnaths
similar in size, or irregular mix of large and small paragnaths in a single band;
rod-shaped paragnaths absent.
Dorsal notopodial ligule markedly elongate on posterior chaetigers; marked-
ly broader on posterior chaetigers. Prechaetal notopodial lobe present; approxi-
mately equal to length of dorsal notopodial ligule at least on anterior chaetigers
(thus notopodium of three similar sized ligules/lobes); present on all chaeti-
gers. Dorsal cirrus sub-terminally attached to dorsal margin of dorsal notopo-
dial ligule on posterior chaetigers; not terminally attached to dorsal notopodial
ligule on anterior or posterior chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
projecting beyond end of the acicular ligule; present throughout all chaetigers;
digitiform. Ventral neuropodial ligule of anterior chaetigers present. Ventral
neuropodial ligule of anterior chaetigers approx. as long as acicular neuropodi-
al ligule. Ventral neuropodial ligule on posterior chaetigers present. Ventral neu-
ropodial ligule on posterior chaetigers similar to length of acicular neuropodial
ligule. Notopodial dorsal ligule with prominent ovoid lobe medial to the dorsal
cirrus in middle and posterior parapodia.
Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph
spinigers present; sesquigomph spinigers present. Neurochaetae dorsal fasci-
cle: heterogomph spinigers present; homogomph spinigers present; sesquigo-
mph spinigers present. Neurochaetae ventral fascicle: heterogomph spinigers
present; homogomph spinigers present; heterogomph falcigers present (in
small specimens); falcigers blade tapering, with straight margin; anterior chae-
tigers heterogomph falcigers with long blades absent; anterior chaetigers het-
erogomph falcigers with extra-long blades present; anterior chaetigers hetero-
gomph falcigers with short blades absent; posterior chaetigers heterogomph
falcigers with long blades absent; posterior chaetigers heterogomph falcigers
with extra-long blades present; posterior chaetigers heterogomph falcigers
with short blades absent.
Anal cirri form cirriform or conical.
Remarks. Nectoneanthes was treated as a synonym of Neanthes by Wilson
(1988) and Bakken and Wilson (2005). Sato (2013) showed Wilson (1988) to be
incorrect in treating Nectoneanthes oxypoda (Marenzeller, 1879) as an epitokal
form and resurrected Nectoneanthes and described a second species for the
genus. The description by Sato (2013) is followed here.
Sato (2013) provided a key to the two species of Nectoneanthes; both spe-
cies occur on the north-west Pacic coast, with N. oxypoda also recorded by
Sato (2013) from southern Australia and the Persian Gulf.
Nereis Linnaeus, 1758
Heteronereis Örsted, 1843.
Johnstonia Quatrefages, 1850.
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Lycoris Lamarck, 1818.
Naumachius Kinberg, 1865.
Nereis (Nereis) auctt.
Thoosa Kinberg, 1865.
Type species. Nereis pelagica Linnaeus, 1758.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129379.
Sources. Bakken et al. (2022).
Diagnosis. Notochaetae homogomph falcigers present; maxillary ring parag-
naths present; Area II rod-like paragnaths absent; dorsal notopodial ligule not
markedly elongate on posterior chaetigers; antennae present; oral ring papillae
absent (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from base
to palpostyle (not overly large compared with palpostyle). Palpophore surface
with a single transverse groove (palpophores well developed). Eyes present, or
absent. Tentacular belt greater than length of chaetiger 1.
Oesophageal caeca present, or absent.
Jaws with smooth or slightly crenulate cutting edge or with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present, or absent; II conical paragnaths
present, or absent; III conical paragnaths present, or absent; III rod-like parag-
naths absent; IV paragnaths present; IV conical paragnaths present; IV smooth
bar-like paragnaths present, or absent; IV rod-like paragnaths absent. Oral
ring papillae absent. Oral ring paragnaths present, or absent; Areas V, VI, and
VII-VIII discrete, forming distinct groups. Area V conical paragnaths present,
or absent; arranged in a triangle, or in a longitudinal line. Area VI paragnaths
present, or absent; paragnaths arranged in a roughly circular group; conical
paragnaths present; smooth bars absent. Areas VII-VIII paragnaths present,
or absent; conical paragnaths present; conical paragnaths arranged in one or
more irregular lines forming a continuous band; conical paragnaths similar
in size, or irregular mix of large and small paragnaths in a single band; rod-
shaped paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; markedly reduced on posterior chae-
tigers, or not markedly reduced on posterior chaetigers. Prechaetal notopodial
lobe present, or absent; smaller than dorsal notopodial ligule on anterior chae-
tigers, usually reduced or absent posteriorly; restricted to a limited number
of anterior chaetigers. Notopodial acicular process absent. Dorsal cirrus not
sub-terminally attached to dorsal notopodial ligule on posterior chaetigers; not
terminally attached to dorsal notopodial ligule on posterior chaetigers; not ter-
minally attached throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe absent.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodi-
al ligule of anterior chaetigers approx. as long as acicular neuropodial ligule.
Ventral neuropodial ligule on posterior chaetigers present. Ventral neuropodial
ligule on posterior chaetigers similar to length of acicular neuropodial ligule, or
short, up to half length of acicular neuropodial ligule.
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Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present; homogomph falcigers present. Neurochaetae dorsal fascicle:
heterogomph spinigers absent; homogomph spinigers present; heterogomph
falcigers in anterior chaetigers present, or absent; on posterior chaetigers
present; blades serrated; blades with teeth only slightly longer proximally than
distally. Neurochaetae ventral fascicle: heterogomph spinigers present, or ab-
sent; spinigers in anterior chaetigers with blades evenly serrated throughout;
on posterior chaetigers with blades nely serrated proximally; homogomph
spinigers absent; heterogomph falcigers present, or absent; anterior chaetigers
heterogomph falcigers with long blades present, or absent; anterior chaetigers
heterogomph falcigers with extra-long blades present, or absent; anterior chae-
tigers heterogomph falcigers with short blades absent; posterior chaetigers
heterogomph falcigers with long blades present, or absent; posterior chaeti-
gers heterogomph falcigers with extra-long blades present, or absent; posterior
chaetigers heterogomph falcigers with short blades present, or absent; hetero-
gomph falcigers blade lacking distinct tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. Nereis is the type taxon of the family Nereididae. It is a large as-
semblage of species, currently with 226 species attributed to the genus, many
that probably belong in other genera. There are no revisions of the genus, or
parts of it, or any that delineate species into informal subgroups. The descrip-
tion here follows Bakken et al. (2022). Some species are treated as part of
revisions of single species or of several similar species (e.g., Salazar-Vallejo
et al. 2021), or in treatments of species belonging to the genus in a regional
perspective (e.g., Hsueh 2020).
Species of Nereis have been found from the littoral zone to abyssal areas,
and from a wide range of habitats.
No complete identication guide to species is available but several useful
keys of restricted scope have been published: Ramírez-Hernández et al. (2015)
has a key to 22 species occurring in the Grand Caribbean, Hsueh (2020) in-
cludes a key to 32 species reported from East Asia, and Salazar-Vallejo et al.
(2021) has a key to the 11 species previously confused with N. falsa de Qua-
trefages, 1866.
Nicon Kinberg, 1865
Type species. Nicon pictus Kinberg, 1865.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=173735.
Sources. Pettibone (1971).
Diagnosis. Maxillary ring paragnaths and papillae absent; neuropodial post-
chaetal lobe present; dorsal notopodial ligule commences chaetiger 3; dorsal
notopodial ligule not markedly reduced on posterior chaetigers; oral ring parag-
naths absent; notochaetae homogomph falcigers absent (minimal diagnosis;
secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from base
to palpostyle (not overly large compared with palpostyle). Palpophore surface
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with a single transverse groove (palpophores well developed). Eyes present, or
absent. Tentacular belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae and paragnaths absent. Oral ring
papillae and paragnaths absent.
Dorsal notopodial ligule present, or absent; not markedly elongate on pos-
terior chaetigers; not markedly broader on posterior chaetigers; not markedly
reduced on posterior chaetigers. Prechaetal notopodial lobe present, or absent;
smaller than dorsal notopodial ligule on anterior chaetigers, usually reduced or
absent posteriorly; restricted to a limited number of anterior chaetigers. No-
topodial acicular process absent. Dorsal cirrus not sub-terminally attached to
dorsal notopodial ligule on posterior chaetigers; not terminally attached to dor-
sal notopodial ligule on posterior chaetigers; not terminally attached through-
out all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
projecting beyond end of the acicular ligule; present throughout all chaetigers,
or restricted to anterior chaetigers; digitiform. Ventral neuropodial ligule of
anterior chaetigers present. Ventral neuropodial ligule of anterior chaetigers
approx. as long as acicular neuropodial ligule. Ventral neuropodial ligule on
posterior chaetigers present. Ventral neuropodial ligule on posterior chaetigers
similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers present, or
absent; homogomph spinigers present; heterogomph falcigers in anterior chae-
tigers present, or absent; on posterior chaetigers present, or absent; blades
serrated; simple chaetae (fused falcigers) present, or absent; homogomph fal-
cigers in anterior chaetigers present, or absent. Neurochaetae ventral fasci-
cle: sesquigomph falcigers present, or absent; heterogomph spinigers present,
or absent; homogomph spinigers present, or absent; heterogomph falcigers
present; anterior chaetigers heterogomph falcigers with long blades absent;
anterior chaetigers heterogomph falcigers with extra-long blades present; an-
terior chaetigers heterogomph falcigers with short blades absent; posterior
chaetigers heterogomph falcigers with long blades present, or absent; poste-
rior chaetigers heterogomph falcigers with extra-long blades present, or ab-
sent; posterior chaetigers heterogomph falcigers with short blades absent;
heterogomph falcigers blade with recurved terminal tooth and distinct tendon,
or lacking distinct tendon on terminal tooth; homogomph falcigers in anterior
chaetigers present, or absent.
Pygidium bilobate. Anal cirri form cirriform or conical.
Remarks. Nicon is not a species-rich genus: of the 700+ species of Nereidi-
dae, only ten belong to the genus Nicon and those ten species are from diverse
habitats and widespread regions (Read and Fauchald 2023). Nicon species
exhibit more morphologically diversity than seen in many genera of Nereididae
and with only a single species included in the most recent study (Wang et al.
2021), both their phylogenetic placement within Nereididae and their mono-
phyly are doubtful.
The two most recent studies describing new Nicon species, de León-
González and Trovant (2013) and Wang et al. (2021), both also provided keys
to the then-known species.
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Olganereis Hartmann-Schröder, 1977
Type species. Ceratocephala edmondsi Hartman, 1954.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324865.
Sources. Hartmann-Schröder (1977).
Diagnosis. Maxillary ring of pharynx with papillae present; dorsal notopodial
ligule markedly reduced on posterior chaetigers; ventral neuropodial ligule of
anterior chaetigers present (minimal diagnosis). Ventral neuropodial ligule of
anterior chaetigers short, up to half length of acicular neuropodial ligule; oral
ring papillae present; prostomium anterior margin entire; Area V papillae absent
(secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Tentacular belt
greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae present; solitary. Maxillary ring parag-
naths absent. Oral ring papillae present. Oral ring papillae arrangement solitary.
Area V papillae absent; VI papillae present; VII-VIII papillae present. Oral ring
paragnaths absent.
Dorsal notopodial ligule present; commences chaetiger 3; not markedly elon-
gate on posterior chaetigers; not markedly broader on posterior chaetigers;
markedly reduced on posterior chaetigers.
Neuropodial prechaetal lobe present. Ventral neuropodial ligule of anterior
chaetigers present. Ventral neuropodial ligule of anterior chaetigers short, up to
half length of acicular neuropodial ligule. Ventral neuropodial ligule on posteri-
or chaetigers present. Ventral neuropodial ligule on posterior chaetigers similar
to length of acicular neuropodial ligule.
Notochaetae: homogomph spinigers present. Neurochaetae dorsal fas-
cicle: heterogomph spinigers absent; homogomph spinigers present; het-
erogomph falcigers in anterior chaetigers present; on posterior chaetigers
present; blades serrated; blades with teeth only slightly longer proximally
than distally. Neurochaetae ventral fascicle: heterogomph spinigers pres-
ent; spinigers in anterior chaetigers with blades evenly serrated throughout;
on posterior chaetigers with blades nely serrated proximally; homogomph
spinigers absent; heterogomph falcigers present; falcigers blade bowed,
with convex margin; heterogomph falcigers blade with recurved terminal
tooth and distinct tendon.
Anal cirri form cirriform or conical.
Remarks. Ceratocephala edmondsi Hartman, 1954 (misspelling for Cerato-
cephale) was separated into the new genus Olganereis by Hartmann-Schröder
(1977) because of the lack of accessory ventral cirri and presence of papillae
on both oral and maxillary rings of the pharynx (characters present in Cerato-
cephale species).
Olganereis is monotypic and the sole species O. edmondsi (Hartman, 1954)
occurs in estuaries in southern Australia. The only other Australian nereidid
with papillae on both rings of the pharynx is Dendronereides heteropoda South-
ern, 1921 from tropical estuaries and in which the dorsal notopodial ligule is
divided into 'branchial' laments.
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Paraleonnates Khlebovich & Wu, 1962
Ganganereis Misra, 1999.
Periserrula Paik, 1977.
Type species. Paraleonnates uschakovi Chlebovitsch & Wu, 1962.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324866.
Sources. Hong et al. (2012).
Diagnosis. Neurochaetae dorsal fascicle homogomph spinigers absent; oral
ring papillae present; prostomium anterior margin entire (minimal diagnosis;
secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore
surface with a single transverse groove (palpophores well developed).
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present, or absent; II conical paragnaths
present; III conical paragnaths present; III rod-like paragnaths absent; IV parag-
naths present; IV conical paragnaths present; IV rod-like paragnaths absent.
Oral ring papillae present. Oral ring papillae arrangement solitary. Area V papil-
lae present, or absent; VI papillae present; VII-VIII papillae present. Oral ring
paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; not markedly reduced on posterior
chaetigers. Prechaetal notopodial lobe present; approximately equal to length
of dorsal notopodial ligule at least on anterior chaetigers (thus notopodium of
three similar sized ligules/lobes). Dorsal cirrus not sub-terminally attached to
dorsal notopodial ligule on posterior chaetigers; not terminally attached to dor-
sal notopodial ligule on posterior chaetigers; not terminally attached through-
out all chaetigers.
Neuropodial postchaetal lobe present; projecting beyond end of the acic-
ular ligule. Ventral neuropodial ligule of anterior chaetigers present. Ventral
neuropodial ligule of anterior chaetigers approx. as long as acicular neuropo-
dial ligule. Ventral neuropodial ligule on posterior chaetigers present. Ventral
neuropodial ligule on posterior chaetigers similar to length of acicular neu-
ropodial ligule.
Notochaetae: homogomph spinigers present. Neurochaetae dorsal fascicle:
heterogomph spinigers present; homogomph spinigers absent. Neurochaetae
ventral fascicle: heterogomph spinigers present; homogomph spinigers absent;
heterogomph falcigers present, or absent; heterogomph falcigers blade lacking
distinct tendon on terminal tooth; homogomph falcigers in anterior chaetigers
present, or absent; on posterior chaetigers present, or absent.
Anal cirri form cirriform or conical.
Remarks. The most recent taxonomic treatments of Paraleonnates are those
of Hong et al. (2012) and Conde-Vela (2019a) which form the basis of the de-
scription and diagnosis provided here. Paraleonnates is a genus of four species
which occur in shallow muddy habitats, typically estuaries and mangroves, in
the Indo-Pacic.
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Conde-Vela (2019a) provides a key to three species of Paraleonnates but
omits Paraleonnates tenuipalpa (Pugfelder, 1933) which had been moved to
Paraleonnates by Glasby et al. (2009); however, Glasby et al. (2009: 15) also
note that P. tenuipalpa may be a senior synonym of Paraleonnates bolus (Hutch-
ings & Reid, 1991).
Parasetia Villalobos-Guerrero, Conde-Vela & Sato, 2022
Type species. Nereis irritabilis Webster, 1879.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=1600661.
Sources. Villalobos-Guerrero et al. (2022a).
Diagnosis. Neurochaetae dorsal fascicle sesquigomph falcigers present;
palpophore massive subconical, attened (palpostyle is minute by compari-
son); oral ring papillae absent (minimal diagnosis). Neurochaetae ventral fas-
cicle sesquigomph falcigers present; neuropodial postchaetal lobe not project-
ing beyond end of the acicular ligule (secondary diagnosis).
Description. Palpophore massive subconical, attened (palpostyle is min-
ute by comparison). Prostomium longitudinal groove present; anterior region
entire, hemispherical, longitudinal groove present; prostomial posterior region
as long as anterior region. Tentacular belt greater than length of chaetiger 1.
Oesophageal caeca absent.
Jaws with smooth or slightly crenulate cutting edge.
Everted pharynx a truncate cone, tapering, greatest width at margin of ten-
tacular belt.
Maxillary ring paragnaths present. Area I conical paragnaths absent; II con-
ical paragnaths present; III conical paragnaths present; IV paragnaths present;
IV conical paragnaths present. Oral ring paragnaths absent.
Dorsal notopodial ligule not markedly reduced on posterior chaetigers. Pre-
chaetal notopodial lobe present; restricted to a limited number of anterior chae-
tigers. Notopodial acicular process present, or absent.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
not projecting beyond end of the acicular ligule; restricted to anterior chae-
tigers; digitiform. Ventral neuropodial ligule of anterior chaetigers present.
Ventral neuropodial ligule of anterior chaetigers approx. as long as acicular
neuropodial ligule. Ventral neuropodial ligule on posterior chaetigers present.
Ventral neuropodial ligule on posterior chaetigers similar to length of acicular
neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers absent;
homogomph spinigers present; sesquigomph falcigers present; heterogomph
falcigers in anterior chaetigers absent; on posterior chaetigers absent. Neuro-
chaetae ventral fascicle: sesquigomph falcigers present; heterogomph spini-
gers present; homogomph spinigers absent; heterogomph falcigers absent;
falcigers blade bowed, with convex margin.
Anal cirri form cirriform or conical.
Remarks. Parasetia was established by Villalobos-Guerrero et al. (2022a)
for Nereis irritabilis Webster, 1878, removed from Composetia due to absence
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of oesophageal caeca and other morphological differences from a redened
Composetia. Parasetia irritabilis (Webster, 1878) occurs on the Atlantic coast
of North America down to a depth of ~ 50 m.
Perinereis Kinberg, 1865
Arete Kinberg, 1865.
Gnatholycastis Ehlers, 1920.
Lipephile Malmgren, 1867.
Nereis (Lipephile) Malmgren, 1867.
Nereis (Perinereis) auctt.
Type species. Perinereis novaehollandiae Kinberg, 1865.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129380.
Sources. Bakken et al. (2022); de León-González and Goethel (2013).
Diagnosis. Palpophore massive subconical, attened (palpostyle is minute
by comparison); oral ring paragnaths present; Area VI smooth bars present;
antennae present (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore massive subconical, attened (palpostyle is minute
by comparison). Palpophore surface with a single transverse groove (palpo-
phores well developed). Tentacular belt greater than length of chaetiger 1.
Jaws with smooth or slightly crenulate cutting edge or with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present or absent; II conical paragnaths
present or absent; III conical paragnaths present; III rod-like paragnaths absent;
IV paragnaths present; IV conical paragnaths present or absent; IV smooth bar-
like paragnaths present, or absent; IV rod-like paragnaths absent. Oral ring papil-
lae absent. Oral ring paragnaths present; with Areas V, VI, and VII-VIII discrete;
on Areas V and VI form distinct groups. Area V conical paragnaths present, or
absent; arranged in a triangle, or in a longitudinal line. Area VI paragnaths pres-
ent, arranged in lines or arcs; conical paragnaths present, or absent; smooth
bars present. Areas VII-VIII paragnaths present, or absent; conical paragnaths
present; conical paragnaths arranged in one or more irregular lines forming a
continuous band; conical paragnaths similar in size, or irregular mix of large
and small paragnaths in a single band; rod-shaped paragnaths absent.
Dorsal notopodial ligule markedly elongate on posterior chaetigers, or not
markedly elongate on posterior chaetigers; not markedly broader on posterior
chaetigers; not markedly reduced on posterior chaetigers. Prechaetal notopo-
dial lobe present, or absent; smaller than dorsal notopodial ligule on anterior
chaetigers, usually reduced or absent posteriorly; restricted to a limited number
of anterior chaetigers. Dorsal cirrus sub-terminally attached to dorsal margin of
dorsal notopodial ligule on posterior chaetigers, or not sub-terminally attached
to dorsal notopodial ligule on posterior chaetigers; not terminally attached
to dorsal notopodial ligule on posterior chaetigers; not terminally attached
throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe absent, or
present; projecting beyond end of the acicular ligule; present throughout all chae-
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tigers, or restricted to anterior chaetigers. Ventral neuropodial ligule of anterior
chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx. as
long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior chaeti-
gers present. Ventral neuropodial ligule on posterior chaetigers similar to length of
acicular neuropodial ligule, or short, up to half length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers absent;
homogomph spinigers present; heterogomph falcigers in anterior chaetigers
present; on posterior chaetigers present; blades serrated; blades with teeth only
slightly longer proximally than distally, or much longer proximally than distally.
Neurochaetae ventral fascicle: heterogomph spinigers present, or absent; spin-
igers in anterior chaetigers with blades evenly serrated throughout, or coarsely
serrated proximally; on posterior chaetigers with blades nely serrated proxi-
mally; homogomph spinigers absent; heterogomph falcigers present; anterior
chaetigers heterogomph falcigers with long blades present, or absent; anterior
chaetigers heterogomph falcigers with extra-long blades present, or absent; an-
terior chaetigers heterogomph falcigers with short blades present, or absent;
posterior chaetigers heterogomph falcigers with long blades present, or absent;
posterior chaetigers heterogomph falcigers with extra-long blades present, or
absent; posterior chaetigers heterogomph falcigers with short blades present, or
absent; heterogomph falcigers blade lacking distinct tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. The genus Perinereis contains 97 species and is thus one of the
most species-rich in the family (Elgetany et al. 2022). Species of Perinereis are
recorded from global locations but are most common in shallow water, particu-
larly where algae occur. There is much morphological diversity within the genus,
notably in respect of the form of Area VI paragnaths and of notopodial lobes, so
for practical identication purposes informal groupings of species have been pro-
posed (Hutchings et al. 1991). One such grouping, the Perinereis nuntia species
complex, has been the subject of several recent studies combing morphological
and molecular evidence and is probably not monophyletic (Tosuji et al. 2019; Vil-
lalobos-Guerrero 2019; Elgetany et al. 2022). The monophyly of the other informal
groupings remains untested. Glasby (2015) provides a key to Nereididae from
tropical eastern Australia and Villalobos-Guerrero (2019) presents a key to 20
species then known in the Perinereis nuntia species complex. Most other keys to
species of Perinereis are now of limited use since they predate the most recent 20
or so papers which add signicantly to knowledge of diversity within the genus.
Platynereis Kinberg, 1865
Iphinereis Malmgren, 1865.
Pisenoe Kinberg, 1866.
Leontis Malmgren, 1867.
Nectonereis Verrill, 1873.
Uncinereis Chamberlin, 1919.
Nereis (Platynereis) auctt.
Type species. Platynereis magalhaensis Kinberg, 1865.
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WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129381.
Sources. Bakken et al. (2022); Read (2007).
Diagnosis. Areas VII-VIII rod-shaped paragnaths present (minimal diagno-
sis). Notochaetae homogomph falcigers with terminal tendon present (second-
ary diagnosis).
Description. Palps anteriorly directed, or ventrally directed. Palpophore bar-
rel-shaped, approximately equal width from base to palpostyle (not overly large
compared with palpostyle). Palpophore surface with a single transverse groove
(palpophores well developed). Tentacular belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area II rod-like paragnaths present; III conical paragnaths absent;
III rod-like paragnaths present; IV paragnaths present; IV conical paragnaths
absent; IV rod-like paragnaths present. Oral ring papillae present, or absent.
Oral ring paragnaths present; on Area V and VI form distinct groups. Area V
conical paragnaths absent. Area VI paragnaths present; conical paragnaths
absent; rod-shaped paragnaths present. Areas VII-VIII paragnaths present;
conical paragnaths absent; conical paragnaths arranged in isolated patch-
es, or in one or more irregular lines forming a continuous band; rod-shaped
paragnaths present.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; not markedly reduced on posteri-
or chaetigers. Dorsal cirrus sub-terminally attached to dorsal margin of dor-
sal notopodial ligule on posterior chaetigers; not terminally attached to dorsal
notopodial ligule on posterior chaetigers; not terminally attached throughout
all chaetigers.
Neuropodial postchaetal lobe absent. Ventral neuropodial ligule of anterior
chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx.
as long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior
chaetigers present. Ventral neuropodial ligule on posterior chaetigers similar to
length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present; homogomph falcigers present; with terminal tendon present; ar-
ticulation fused on some chaetigers (present as a simple chaeta), or with blade
free throughout. Neurochaetae dorsal fascicle: heterogomph spinigers absent;
homogomph spinigers present; heterogomph falcigers in anterior chaetigers
present; on posterior chaetigers present; blades serrated; blades with teeth
only slightly longer proximally than distally. Neurochaetae ventral fascicle: het-
erogomph spinigers present; spinigers in anterior chaetigers with blades evenly
serrated throughout; on posterior chaetigers with blades nely serrated proxi-
mally; homogomph spinigers absent; heterogomph falcigers present; anterior
chaetigers heterogomph falcigers with long blades absent; anterior chaetigers
heterogomph falcigers with extra-long blades present; anterior chaetigers het-
erogomph falcigers with short blades absent; heterogomph falcigers blade
lacking distinct tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. Species belonging to Platynereis are easily recognised by the
small rod-like paragnaths in tight rows on the pharynx; 36 species are rec-
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ognised. No revisions have been published, but regional studies using molec-
ular data to revise species to resolve the complex taxonomy, and taxonomic
history of this genus have been appearing (Wäge et al. 2017; Kara et al. 2020;
Teixeira et al. 2022b). Morphological characters from reproductive specimens
(epitokes) may be important to distinguish species (Read 2007). Species of
Platynereis are found in tropical, temperate and sub-Arctic waters, primarily in
shallow water among algae.
Potamonereis Villalobos-Guerrero, Conde-Vela & Sato, 2022
Type species. Composetia kumensis Sato, 2020.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=1600677.
Sources. Villalobos-Guerrero et al. (2022a).
Diagnosis. Maxillary ring paragnaths present; neuropodial postchaetal lobe
not projecting beyond end of the acicular ligule; notoaciculae on chaetigers 1
and 2 present; prostomium anterior margin entire (minimal diagnosis; second-
ary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Prostomium
longitudinal groove present; anterior region entire, hemispherical, longitudinal
groove present; prostomial posterior region shorter than anterior region. Ten-
tacular belt greater than length of chaetiger 1.
Oesophageal caeca absent.
Jaws with dentate cutting edge.
Everted pharynx a truncate cone, tapering, greatest width at margin of ten-
tacular belt.
Maxillary ring paragnaths present. Area I conical paragnaths present, or ab-
sent; II conical paragnaths present; III conical paragnaths present; III conical
paragnaths isolated lateral groups absent; IV paragnaths present; IV conical
paragnaths present. Oral ring paragnaths absent.
Prechaetal notopodial lobe absent. Dorsal cirrus not sub-terminally attached
to dorsal notopodial ligule on posterior chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
not projecting beyond end of the acicular ligule; restricted to anterior chaeti-
gers; digitiform. Ventral neuropodial ligule of anterior chaetigers present.
Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph
spinigers present. Neurochaetae dorsal fascicle: heterogomph spinigers pres-
ent, or absent; homogomph spinigers present; heterogomph falcigers in ante-
rior chaetigers present; on posterior chaetigers present. Neurochaetae ventral
fascicle: heterogomph spinigers present; homogomph spinigers absent; het-
erogomph falcigers present; falcigers blade tapering, with straightmargin.
Anal cirri form cirriform or conical.
Remarks. Potamonereis was established by Villalobos-Guerrero et al.
(2022a) for two former species of Composetia in which oesophageal caeca
are absent and which have a truncate-conical pharynx, and other morphologi-
cal differences (at the same time those authors redened Composetia). Both
species of Potamonereis occur in the North-west Pacic in Japanese estuaries.
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Pseudonereis Kinberg, 1865
Phyllonereis Hansen, 1882.
Type species. Pseudonereis gallapagensis Kinberg, 1865.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129382.
Sources. Conde-Vela (2018); Villalobos-Guerrero and Idris (2020).
Diagnosis. Maxillary ring of pharynx with P-bar paragnaths present, usually
in regular comb-like rows (minimal diagnosis). Area VI shield-shaped bars pres-
ent (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore sur-
face with a single transverse groove (palpophores well developed). Tentacular
belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present; of pharynx with P-bar paragnaths present, usually in regular comb-like
rows. Area I conical paragnaths present; II conical paragnaths present; III con-
ical paragnaths present; III rod-like paragnaths absent; IV paragnaths present;
IV conical paragnaths present; IV rod-like paragnaths absent. Oral ring papillae
absent. Oral ring paragnaths present; with Areas V, VI and VII-VIII discrete; on
Area V and VI form distinct groups. Area V conical paragnaths present, or ab-
sent. Area VI paragnaths present; paragnaths arranged in lines or arcs; conical
paragnaths present, or absent; smooth bars present, or absent; shield-shaped
bars present. Areas VII-VIII paragnaths present; conical paragnaths present;
conical paragnaths arranged in one or more irregular lines forming a continu-
ous band; conical paragnaths similar in size, or irregular mix of large and small
paragnaths in a single band; P-bar paragnaths absent, or present.
Dorsal notopodial ligule markedly elongate on posterior chaetigers; markedly
broader on posterior chaetigers; not markedly reduced on posterior chaetigers.
Prechaetal notopodial lobe present, or absent. Notopodial acicular process ab-
sent. Dorsal cirrus not sub-terminally attached to dorsal notopodial ligule on
posterior chaetigers; terminally attached to dorsal notopodial ligule on posteri-
or chaetigers; not terminally attached throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe absent,
or present; projecting beyond end of the acicular ligule; restricted to anterior
chaetigers; digitiform, or attened. Ventral neuropodial ligule of anterior chae-
tigers present. Ventral neuropodial ligule on posterior chaetigers present. Ven-
tral neuropodial ligule on posterior chaetigers similar to length of acicular neu-
ropodial ligule, or short, up to half length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present; homogomph falcigers present, or absent. Neurochaetae dorsal
fascicle: heterogomph spinigers present, or absent; homogomph spinigers
present, or absent; heterogomph falcigers in anterior chaetigers present; on
posterior chaetigers present; blades serrated; blades with teeth only slightly
longer proximally than distally. Neurochaetae ventral fascicle: homogomph
spinigers absent; heterogomph falcigers present; heterogomph falcigers blade
lacking distinct tendon on terminal tooth.
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Anal cirri form cirriform or conical.
Remarks. Pseudonereis species are characterised by presence of both
P-bars and comb-like rows of paragnaths in Areas II-IV (Villalobos-Guerrero
and Idris 2020). The genus was found to be a monophyletic group and could be
diagnosed from morphological characters (Bakken and Wilson 2005; Bakken
2007). More species have been described in recent years, and the genus de-
scription has been emended (Glasby 2015; Conde-Vela 2018; Villalobos-Guer-
rero and Idris 2020). The description used here follows Villalobos-Guerrero and
Idris (2020). Kara et al. (2018) investigated relationships between several spe-
cies using molecular data.
Species in this genus are primarily found in tropical and subtropical waters,
in shallow depths. Following the last work including revised species, the genus
includes 19 species (Villalobos-Guerrero and Idris 2020).
Rullierinereis Pettibone, 1971
Profundilycastis Hartmann-Schröder, 1977.
Type species. Leptonereis zebra Rullier, 1963.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129383.
Sources. Pettibone (1971); Tanaka and Sato (2017).
Diagnosis. Notochaetae homogomph falcigers present; maxillary ring parag-
naths absent; neurochaetae ventral fascicle heterogomph spinigers absent
(minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Tentacular belt
greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae present, or absent. Oral ring paragnaths absent.
Dorsal notopodial ligule present; commences chaetiger 3; not markedly elon-
gate on posterior chaetigers (and may be fused with dorsal cirri); not marked-
ly broader on posterior chaetigers; markedly reduced on posterior chaetigers.
Dorsal cirrus not sub-terminally attached to dorsal notopodial ligule on poste-
rior chaetigers; not terminally attached to dorsal notopodial ligule on posterior
chaetigers; not terminally attached throughout all chaetigers.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodi-
al ligule of anterior chaetigers approx. as long as acicular neuropodial ligule.
Ventral neuropodial ligule on posterior chaetigers present. Ventral neuropodial
ligule on posterior chaetigers similar to length of acicular neuropodial ligule.
Notochaetae: homogomph spinigers present; homogomph falcigers present
(on posterior chaetigers). Neurochaetae dorsal fascicle: heterogomph spini-
gers absent; homogomph spinigers present; heterogomph falcigers in anterior
chaetigers present; on posterior chaetigers present; blades serrated; blades
with teeth only slightly longer proximally than distally. Neurochaetae ventral
fascicle: heterogomph spinigers absent; homogomph spinigers absent; het-
erogomph falcigers present; anterior chaetigers heterogomph falcigers with
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long blades absent; anterior chaetigers heterogomph falcigers with extra-long
blades present; anterior chaetigers heterogomph falcigers with short blades
absent; posterior chaetigers heterogomph falcigers with long blades present;
posterior chaetigers heterogomph falcigers with short blades present.
Anal cirri form cirriform or conical.
Remarks. Rullierinereis is a genus with similarities to Nicon and Typhlonereis
but differing in having notopodial homogomph falcigers (Tanaka and Sato 2017).
Fifteen species of Rullierinereis are recognised and they occur widely around the
world from shallow water to abyssal depths (4800 m). Tanaka and Sato (2017)
revised the generic description. The only key to species is that of Pettibone
(1971), but since that time nine additional species have been described.
Simplisetia Hartmann-Schröder, 1985
Ceratonereis (Simplisetia) Hartmann-Schröder, 1985.
Type species. Nereis (Ceratonereis) aequisetis Augener, 1913.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324869.
Sources. Hartmann-Schröder (1985); Bakken and Wilson (2005).
Diagnosis. Neurochaetae dorsal fascicle simple chaetae (fused falcigers)
present; palpophore barrel-shaped, approximately equal width from base to pal-
postyle (not overly large compared with palpostyle); maxillary ring paragnaths
present (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Palpophore
surface with a single transverse groove (palpophores well developed).
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present, or absent; II conical paragnaths
present; III conical paragnaths present; III rod-like paragnaths absent; IV parag-
naths present; IV conical paragnaths present; IV rod-like paragnaths absent.
Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers (rarely markedly reduced on posterior
chaetigers). Prechaetal notopodial lobe present, or absent; smaller than dorsal
notopodial ligule on anterior chaetigers, usually reduced or absent posteriorly; re-
stricted to a limited number of anterior chaetigers. Notopodial acicular process
present, or absent. Dorsal cirrus not sub-terminally attached to dorsal notopo-
dial ligule on posterior chaetigers; not terminally attached to dorsal notopodial
ligule on posterior chaetigers; not terminally attached throughout all chaetigers.
Neuropodial postchaetal lobe absent, or present; projecting beyond end of
the acicular ligule; restricted to anterior chaetigers; digitiform. Ventral neuropo-
dial ligule of anterior chaetigers present. Ventral neuropodial ligule of anterior
chaetigers approx. as long as acicular neuropodial ligule. Ventral neuropodial
ligule on posterior chaetigers present. Ventral neuropodial ligule on posterior
chaetigers similar to length of acicular neuropodial ligule, or short, up to half
length of acicular neuropodial ligule.
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Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers present,
or absent (only in S. lizardensis); homogomph spinigers present; heterogomph
falcigers in anterior chaetigers present; on posterior chaetigers present; simple
chaetae (fused falcigers) present. Neurochaetae ventral fascicle: heterogomph
spinigers present; homogomph spinigers present (only in Simplisetia sp. from
Phuket), or absent; heterogomph falcigers present; anterior chaetigers hetero-
gomph falcigers with long blades absent; anterior chaetigers heterogomph
falcigers with extra-long blades present; anterior chaetigers heterogomph fal-
cigers with short blades absent; posterior chaetigers heterogomph falcigers
with long blades present, or absent; posterior chaetigers heterogomph fal-
cigers with extra-long blades present, or absent; posterior chaetigers hetero-
gomph falcigers with short blades present, or absent; heterogomph falcigers
blade lacking distinct tendon on terminal tooth.
Anal cirri form cirriform or conical.
Remarks. Simplisetia is a genus of estuarine nereidids characterised by the
presence of fused neuropodial falcigers in posterior chaetigers and absence
of oral ring paragnaths. The fused falcigers are also present in another estu-
arine genus, Hediste, and the two genera may be related (Bakken and Wilson
2005) although they are easily separated by the presence of numerous oral ring
paragnaths in Hediste.
Simplisetia currently includes ten species, seven of which occur in Australian
estuaries. Signicant differences occur among Simplisetia species in the form
of the fused falcigers.
The interactive key of Wilson et al. (2003) allowed identication of the Aus-
tralian species.
Sinonereis Wu & Sun, 1979
Type species. Sinonereis heteropoda Wu & Sun, 1979.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324879.
Sources. Conde-Vela and Wu (2019).
Diagnosis. Dorsal cirrophores of chaetigers 5–7 of epitokes modied into
spherical globular structures (minimal diagnosis). Dorsal notopodial ligule com-
mences chaetiger 4; dorsal notopodial ligule not markedly elongate on posterior
chaetigers; notochaetae homogomph falcigers absent (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle).
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule present; commences chaetiger 4; not markedly re-
duced on posterior chaetigers. Prechaetal notopodial lobe present; present on
all chaetigers. Notopodial acicular process absent. Dorsal cirrus not sub-termi-
nally attached to dorsal notopodial ligule on posterior chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
not projecting beyond end of the acicular ligule; present throughout all chae-
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tigers; digitiform. Ventral neuropodial ligule of anterior chaetigers present.
Ventral neuropodial ligule of anterior chaetigers approx. as long as acicular
neuropodial ligule. Ventral neuropodial ligule on posterior chaetigers present.
Ventral neuropodial ligule on posterior chaetigers similar to length of acicular
neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle: heterogomph spinigers absent;
homogomph spinigers present; heterogomph falcigers in anterior chaetigers
present; on posterior chaetigers present. Neurochaetae ventral fascicle: het-
erogomph spinigers present; homogomph spinigers absent; heterogomph fal-
cigers present; falcigers blade tapering, with straight margin.
Anal cirri form cirriform or conical.
Epitokes. Dorsal cirrophores of chaetigers 5–7 of epitokes modied into
spherical globular structures. Natatory epitokal modications in males com-
mence chaetiger 22. Females without natatory modications.
Remarks. Sinonereis Wu & Sun, 1979 is a monotypic genus originally based
on a single epitokous specimen. An emended description including atokous
characters was provided by Conde-Vela and Wu (2019).
Solomononereis Gibbs, 1971
Type species. Solomononereis marauensis Gibbs, 1971.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324870.
Sources. Nateewathana (1992); Bakken and Wilson (2005).
Diagnosis. Area II rod-like paragnaths present; prostomium anterior margin in-
dented (minimal diagnosis). Notochaetae homogomph falcigers present; dorsal
notopodial ligule markedly reduced on posterior chaetigers (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Prostomium
anterior margin indented. Tentacular belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present; II conical paragnaths absent; II rod-
like paragnaths present; III conical paragnaths absent; III rod-like paragnaths
present; IV paragnaths present; IV conical paragnaths absent; IV rod-like parag-
naths present. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule not markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; markedly reduced on posterior chae-
tigers. Prechaetal notopodial lobe absent. Notopodial acicular process absent.
Dorsal cirrus not sub-terminally attached to dorsal notopodial ligule on poste-
rior chaetigers; not terminally attached to dorsal notopodial ligule on posterior
chaetigers; not terminally attached throughout all chaetigers.
Neuropodial postchaetal lobe absent. Ventral neuropodial ligule of anterior
chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx.
as long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior
chaetigers present. Ventral neuropodial ligule on posterior chaetigers short, up
to half length of acicular neuropodial ligule.
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Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph
spinigers absent; sesquigomph spinigers present; homogomph falcigers pres-
ent; homogomph falcigers with multidentate blade with 2 or more small lateral
teeth, rst and subsequent lateral teeth much smaller than terminal tooth pres-
ent; sesquigomph falcigers present, or absent. Neurochaetae dorsal fascicle:
heterogomph spinigers absent; homogomph spinigers absent; sesquigomph
spinigers present; heterogomph falcigers in anterior chaetigers absent; on
posterior chaetigers present; blades serrated. Neurochaetae ventral fascicle:
heterogomph spinigers present; homogomph spinigers absent; heterogomph
falcigers absent.
Anal cirri form cirriform or conical.
Remarks. Solomononereis is a genus of Nereididae sharing some similar-
ities to members of the larger genus Ceratonereis. Solomononereis, however,
can be distinguished by the presence of rod-like paragnaths on the maxillary
ring. Solomononereis contains two species, both occurring in the tropical In-
do-Pacic to a depth of ~ 30 m. Nateewathana (1992) provides a tabular com-
parison enabling identication of the species.
Stenoninereis Wesenberg-Lund, 1958
Type species. Stenoninereis martini Wesenberg-Lund, 1958.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324872.
Sources. Pettibone (1971); Conde-Vela (2019b).
Diagnosis. Dorsal cirrus arising from basal cirrophore; ventral neuropodial
ligule of anterior chaetigers absent; palpophore surface with a single trans-
verse groove (palpophores well developed) (minimal diagnosis). Oral ring
papillae absent; maxillary ring paragnaths absent; palpostyles subconical
(secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Prostomium
anterior margin indented; longitudinal groove absent. Tentacular belt equal to
or less than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule present; commences chaetiger 3; markedly reduced
on posterior chaetigers. Prechaetal notopodial lobe absent. Notopodial acicu-
lar process absent. Dorsal cirrus not sub-terminally attached to dorsal notopo-
dial ligule on posterior chaetigers; arising from basal cirrophore; cirrophore of
dorsal cirrus much longer than ventral notopodial ligule (and ciliated); cirro-
phore of dorsal cirrus cylindrical throughout.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe present;
not projecting beyond end of the acicular ligule; present throughout all chaeti-
gers; attened (rounded). Ventral neuropodial ligule of anterior chaetigers ab-
sent. Ventral neuropodial ligule on posterior chaetigers absent.
Notoaciculae on chaetigers 1 and 2 present. Notochaetae: homogomph
spinigers absent; sesquigomph spinigers present. Neurochaetae dorsal fasci-
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cle: heterogomph spinigers absent; homogomph spinigers absent; sesquigo-
mph spinigers present; heterogomph falcigers in anterior chaetigers absent;
on posterior chaetigers absent. Neurochaetae ventral fascicle: heterogomph
spinigers present; homogomph spinigers absent; heterogomph falcigers pres-
ent; falcigers blade tapering, with straight margin; anterior chaetigers hetero-
gomph falcigers with long blades absent; anterior chaetigers heterogomph
falcigers with extra-long blades present; anterior chaetigers heterogomph fal-
cigers with short blades absent; posterior chaetigers heterogomph falcigers
with long blades absent; posterior chaetigers heterogomph falcigers with ex-
tra-long blades present; posterior chaetigers heterogomph falcigers with short
blades absent. Neuropodial heterogomph spinigers with blades basally serrate,
coarse teeth, larger teeth longer than blade width, 2/3 of the blade edentate and
subulate. Neuropodial heterogomph falcigers with very long blades, increasing
their length from upper to lower positions in the same fascicle; falcigers with
blades smooth.
Anal cirri form cirriform or conical.
Remarks. Stenoninereis Wesenberg-Lund, 1958 was described for a single spe-
cies, S. martini Wesenberg-Lund, 1958. The genus now includes four small spe-
cies, all occurring in sinkholes in the Caribbean-Mexico-central America region.
Species of Stenoninereis can be identied using the key of Conde-Vela (2019b).
Tambalagamia Pillai, 1961
Type species. Tambalagamia fauveli Pillai, 1961.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324873.
Sources. Shen and Wu (1993).
Diagnosis. Transverse dorsal lamellae present; neurochaetae dorsal fascicle
sesquigomph spinigers absent (minimal diagnosis). Dorsal cirrus arising from
basal cirrophore; tentacular belt greater than length of chaetiger 1; notochaetae
sesquigomph spinigers absent (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Prostomium
anterior margin indented. Tentacular belt greater than length of chaetiger 1.
Jaws with smooth or slightly crenulate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae present. Oral ring papillae arrangement solitary. Area V
papillae present; VII-VIII papillae present. Oral ring paragnaths absent.
Transverse dorsal lamellae present.
Dorsal notopodial ligule present; commences chaetiger 1. Prechaetal no-
topodial lobe present. Dorsal cirrus arising from basal cirrophore; cirrophore
of dorsal cirrus enlarged and vascularised; cirrophore of dorsal cirrus cylin-
drical throughout.
Ventral neuropodial ligule of anterior chaetigers present. Accessory ventral
cirrus present.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph
spinigers present. Neurochaetae dorsal fascicle: heterogomph spinigers ab-
sent; homogomph spinigers present; heterogomph falcigers in anterior chae-
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tigers absent; on posterior chaetigers absent. Neurochaetae ventral fascicle:
heterogomph spinigers absent; homogomph spinigers present; heterogomph
falcigers absent.
Remarks. Tambalagamia Pillai, 1961 is similar to Ceratocephale and, espe-
cially to Gymnonereis, with double ventral cirri being shared characters. Petti-
bone (1970) and Hylleberg and Nateewathana (1988) considered Tambalag-
amia to be a junior synonym of Gymnonereis. We follow Bakken et al. (2022)
and retain Tambalagamia as separate pending phylogenetic analysis with better
taxon sampling of both genera. Tambalagamia currently includes three species
which can be identied using the tabular comparison of Shen and Wu (1993).
Tylonereis Fauvel, 1911
Type species. Tylonereis bogoyawlenskyi Fauvel, 1911.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324874.
Sources. Fauvel (1911).
Diagnosis. Dorsal notopodial ligule markedly broader on posterior chaeti-
gers; prostomium anterior margin indented (minimal diagnosis). Maxillary ring
of pharynx with papillae present; dorsal notopodial ligule markedly elongate on
posterior chaetigers (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Prostomium
anterior margin indented.
Jaws with smooth or slightly crenulate cutting edge.
Maxillary ring of pharynx with papillae present; in tufts. Maxillary ring parag-
naths absent. Oral ring papillae present. Oral ring papillae arrangement solitary.
Area V papillae absent; VI one papillae present; VII-VIII papillae present (in a sin-
gle row). Oral ring paragnaths absent. Maxillary ring papillae absent on Areas I
and II, with double rows on Areas III and IV.
Dorsal notopodial ligule present; commences chaetiger 3; markedly elongate
on posterior chaetigers; markedly broader on posterior chaetigers; not marked-
ly reduced on posterior chaetigers. Dorsal cirrus not sub-terminally attached to
dorsal notopodial ligule on posterior chaetigers; not terminally attached to dor-
sal notopodial ligule on posterior chaetigers; not terminally attached through-
out all chaetigers.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodi-
al ligule of anterior chaetigers approx. as long as acicular neuropodial ligule.
Ventral neuropodial ligule on posterior chaetigers present. Ventral neuropodial
ligule on posterior chaetigers similar to length of acicular neuropodial ligule.
The neuropodial acicular ligule has three or four distinct lobes; homology of
these is unclear, therefore these structures are not scored in this description.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph
spinigers present. Neurochaetae dorsal fascicle: heterogomph spinigers ab-
sent; homogomph spinigers present; heterogomph falcigers in anterior chae-
tigers absent; on posterior chaetigers absent. Neurochaetae ventral fascicle:
heterogomph spinigers absent; homogomph spinigers present; heterogomph
falcigers absent.
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Remarks. Tylonereis is one of several genera of Nereididae from tropical es-
tuaries which have papillae on both maxillary and oral rings of the pharynx. The
genus contains three species, all known from coastal lagoons and lakes of the
tropical Indo-Pacic. Tan and Chou (1994) provide a key to species.
Tylorrhynchus Grube, 1866
Type species. Nereis heterocheta Quatrefages, 1866.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324876.
Sources. Pettibone (1971).
Diagnosis. Dorsal cirrus terminally attached throughout, so that dorsal no-
topodial ligule has appearance of a cirrophore for the dorsal cirrus (minimal diag-
nosis). Acicular notopodial ligule reduced, much shorter than neuropodial acicu-
lar ligule; maxillary ring of pharynx with papillae present (secondary diagnosis).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Prostomium
anterior margin indented. Tentacular belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae present. Maxillary ring paragnaths ab-
sent. Oral ring papillae present. Oral ring paragnaths absent.
Dorsal notopodial ligule absent. Prechaetal notopodial lobe absent. Notopo-
dial acicular process absent. Acicular notopodial ligule reduced, much shorter
than neuropodial acicular ligule. Dorsal cirrus length ~ 5× acicular notopodial
ligule at chaetigers 10–20; not sub-terminally attached to dorsal notopodial
ligule on posterior chaetigers; terminally attached throughout, so that dorsal
notopodial ligule has appearance of a cirrophore for the dorsal cirrus.
Ventral neuropodial ligule of anterior chaetigers absent. Ventral neuropodial
ligule on posterior chaetigers absent. The single notopodial ligule (Pettibone
1971: g. 25b, c, e) apparently has the notoacicula and therefore cannot be the
dorsal notopodial ligule. The homology of the two acicular neuropodial lobes
with those of other nereidids is unclear; therefore, these structures are not
scored in this description.
Notochaetae: homogomph spinigers absent; sesquigomph spinigers pres-
ent. Neurochaetae dorsal fascicle: heterogomph spinigers absent; homogomph
spinigers absent; sesquigomph spinigers present; heterogomph falcigers in
anterior chaetigers present; on posterior chaetigers present; blades serrated.
Neurochaetae ventral fascicle: heterogomph spinigers present; spinigers in an-
terior chaetigers with blades coarsely serrated proximally; on posterior chaeti-
gers with blades coarsely serrated proximally; homogomph spinigers absent;
heterogomph falcigers present; anterior chaetigers heterogomph falcigers with
long blades absent; anterior chaetigers heterogomph falcigers with extra-long
blades present; anterior chaetigers heterogomph falcigers with short blades
absent; posterior chaetigers heterogomph falcigers with long blades absent;
posterior chaetigers heterogomph falcigers with extra-long blades present;
posterior chaetigers heterogomph falcigers with short blades absent.
Epitokes. Epitokes formed by transformation of the anterior part of the body,
with the posterior part cast off (Izuka 1903; Pettibone 1971).
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Robin S. Wilson et al.: The Nereidid worms
Remarks. Tylorrhynchus is known from two species, both of which occur in
estuarine and fresh waters of the western Pacic Ocean (Japan, China) and
the nearby north-east Pacic Ocean (Khlebovich 1996). Additional information
on the biology and timing of swarming is provided by Hanaah et al. (2006).
The best taxonomic resources are Izuka (1903) and Pettibone (1971), at which
time a single species was recognised. Tylorrhynchus is unlike other Nereididae
genera in several ways including the absence of a ventral neuropodial ligule.
Typhlonereis Hansen, 1879
Type species. Typhlonereis gracilis Hansen, 1879.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=324877.
Sources. Bakken (2003).
Diagnosis. Notochaetae of chaetigers 3 and 4 absent (minimal diagnosis).
Dorsal notopodial ligule commences chaetiger 5; dorsal notopodial ligule not
markedly elongate on posterior chaetigers (secondary diagnosis).
Description. Tentacular belt greater than length of chaetiger 1. Tentacular
cirri extend to chaetiger 2 (longest cirrus).
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule present; commences chaetiger 5; not markedly elon-
gate on posterior chaetigers; not markedly broader on posterior chaetigers; mark-
edly reduced on posterior chaetigers. Prechaetal notopodial lobe absent. Notopo-
dial acicular process absent. Dorsal cirrus length ~ 1× acicular notopodial ligule
at chaetigers 10–20; sub-terminally attached to dorsal margin of dorsal notopo-
dial ligule on posterior chaetigers; not terminally attached to dorsal notopodial
ligule on posterior chaetigers; not terminally attached throughout all chaetigers.
Neuropodial prechaetal lobe absent. Neuropodial postchaetal lobe absent.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neuropodi-
al ligule of anterior chaetigers approx. as long as acicular neuropodial ligule.
Ventral neuropodial ligule on posterior chaetigers present. Ventral neuropodial
ligule on posterior chaetigers similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae of chaetigers 3
and 4 absent. Notochaetae: homogomph spinigers present. Neurochaetae
dorsal fascicle: heterogomph spinigers absent; homogomph spinigers pres-
ent; heterogomph falcigers in anterior chaetigers absent; on posterior chae-
tigers absent. Neurochaetae ventral fascicle: heterogomph spinigers present;
homogomph spinigers absent; heterogomph falcigers present; anterior chae-
tigers heterogomph falcigers with long blades absent; anterior chaetigers het-
erogomph falcigers with extra-long blades present; anterior chaetigers hetero-
gomph falcigers with short blades absent; posterior chaetigers heterogomph
falcigers with long blades absent; posterior chaetigers heterogomph falcigers
with extra-long blades present; posterior chaetigers heterogomph falcigers
with short blades absent.
Remarks. Typhlonereis is known from a single species represented by six
specimens from 2222 m in the far North-east Atlantic Ocean (Bakken 2003).
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Robin S. Wilson et al.: The Nereidid worms
The sole species, Typhlonereis gracilis, redescribed by Bakken (2003), is similar
to Nicon and Rullierinereis and perhaps will be shown to belong instead in one
of those genera.
Unanereis Day, 1962
Type species. Unanereis macgregori Day, 1962.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129384.
Sources. Day (1962).
Diagnosis. Dorsal cirrus terminally attached to dorsal notopodial ligule on
posterior chaetigers; dorsal notopodial ligule not markedly broader on poste-
rior chaetigers (minimal diagnosis). Notochaetae sesquigomph falcigers pres-
ent; prostomium anterior margin entire (secondary diagnosis).
Description. Antennae present (described as having a single antenna but
this is here assumed to be a mistake; likely a developmental anomaly or simply
missing). Tentacular belt greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths pres-
ent. Area II conical paragnaths present; III conical paragnaths present; III rod-like
paragnaths absent; IV paragnaths present; IV conical paragnaths present; IV rod-
like paragnaths absent. Oral ring papillae absent. Oral ring paragnaths absent.
Dorsal notopodial ligule markedly elongate on posterior chaetigers; not
markedly broader on posterior chaetigers; not markedly reduced on posterior
chaetigers. Dorsal cirrus not sub-terminally attached to dorsal notopodial ligule
on posterior chaetigers; terminally attached to dorsal notopodial ligule on pos-
terior chaetigers; not terminally attached throughout all chaetigers.
Neuropodial prechaetal lobe present; extending beyond postchaetal lobe (at
least in anterior chaetigers). Neuropodial postchaetal lobe present; projecting
beyond end of the acicular ligule; attened. Ventral neuropodial ligule of anteri-
or chaetigers present. Ventral neuropodial ligule of anterior chaetigers approx.
as long as acicular neuropodial ligule. Ventral neuropodial ligule on posterior
chaetigers present. Ventral neuropodial ligule on posterior chaetigers short, up
to half length of acicular neuropodial ligule.
Notochaetae: homogomph spinigers present; sesquigomph falcigers pres-
ent; blade distally bid. Neurochaetae dorsal fascicle: heterogomph spinigers
absent; homogomph spinigers present; heterogomph falcigers in anterior chae-
tigers present; on posterior chaetigers present. Neurochaetae ventral fascicle:
heterogomph spinigers present; homogomph spinigers absent; heterogomph
falcigers present; heterogomph falcigers blade terminally bid.
Remarks. Unanereis Day, 1962 was described from a single specimen found
in the tube of a species of Terebellidae. A second species, U. zghali Ben Amor,
1980, from a vertical rocky substrate including dendrophyllid coral Astroides
calycularis and algae Corallina mediterranea but without an obvious host, has
been described from the Mediterranean (Ben Amor 1980). As noted by several
studies, the validity of Unanereis is doubtful and the genus may represent devel-
opmental anomalies in specimens belonging to Ceratonereis or Solomonone-
reis (Bakken and Wilson 2005; Santos et al. 2005; Bakken et al. 2022).
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Robin S. Wilson et al.: The Nereidid worms
Websterinereis Pettibone, 1971
Type species. Nereis tridentata Webster, 1879.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=129385.
Sources. Pettibone (1971); de León-González and Balart (2016).
Diagnosis. Oral ring papillae present; neurochaetae dorsal fascicle hetero-
gomph falcigers in anterior chaetigers present; maxillary ring paragnaths ab-
sent; maxillary ring of pharynx with papillae absent; notochaetae homogomph
falcigers absent; oral ring paragnaths absent (minimal diagnosis; secondary
diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from base
to palpostyle (not overly large compared with palpostyle). Palpophore surface
with a single transverse groove (palpophores well developed). Tentacular belt
equal to or less than length of chaetiger 1, or greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths ab-
sent. Oral ring papillae present. Oral ring papillae arrangement solitary. Area V
papillae absent; VI papillae present; VII-VIII papillae present. Oral ring parag-
naths absent.
Dorsal notopodial ligule present; commences chaetiger 3; not markedly elon-
gate on posterior chaetigers; not markedly broader on posterior chaetigers; not
markedly reduced on posterior chaetigers. Prechaetal notopodial lobe present;
smaller than dorsal notopodial ligule on anterior chaetigers, usually reduced
or absent posteriorly; restricted to a limited number of anterior chaetigers. No-
topodial acicular process absent. Dorsal cirrus not sub-terminally attached to
dorsal notopodial ligule on posterior chaetigers; not terminally attached to dor-
sal notopodial ligule on posterior chaetigers; not terminally attached through-
out all chaetigers.
Neuropodial postchaetal lobe present; projecting beyond end of the acicular
ligule; present throughout all chaetigers; digitiform. Ventral neuropodial ligule
of anterior chaetigers present. Ventral neuropodial ligule of anterior chaetigers
approx. as long as acicular neuropodial ligule. Ventral neuropodial ligule on
posterior chaetigers present. Ventral neuropodial ligule on posterior chaetigers
similar to length of acicular neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph
spinigers present. Neurochaetae dorsal fascicle: heterogomph spinigers
absent; homogomph spinigers present; heterogomph falcigers in anterior
chaetigers present; on posterior chaetigers present; blades serrated; blades
with teeth only slightly longer proximally than distally. Neurochaetae ven-
tral fascicle: heterogomph spinigers present; homogomph spinigers absent;
heterogomph falcigers present; anterior chaetigers heterogomph falcigers
with long blades absent; anterior chaetigers heterogomph falcigers with
extra-long blades present; anterior chaetigers heterogomph falcigers with
short blades absent; posterior chaetigers heterogomph falcigers with long
blades present, or absent; posterior chaetigers heterogomph falcigers with
extra-long blades absent; posterior chaetigers heterogomph falcigers with
short blades present, or absent; heterogomph falcigers blade lacking distinct
tendon on terminal tooth.
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Robin S. Wilson et al.: The Nereidid worms
Anal cirri form cirriform or conical.
Remarks. Websterinereis is similar to Rullierinereis in having the anterior mar-
gin of prostomium entire, the maxillary ring bare and papillae on the oral ring;
Websterinereis differs from Rullierinereis in lacking notopodial homogomph
falcigers. There are ve species of Websterinereis which are known from the
Atlantic, Indian, and Pacic Oceans, mostly from shallow water (less than ~
130 m) except for W. glauca, which is recorded to a maximum depth of 3310m.
The genus was revised by de León-González and Balart (2016) who provide a
key to species.
Wuinereis Khlebovich, 1996
Type species. Leonnates simplex Monro, 1939.
WoRMS URL. https://www.marinespecies.org/polychaeta/aphia.
php?p=taxdetails&id=1039985.
Sources. Bakken et al. (2022).
Diagnosis. Oral ring papillae present; maxillary ring paragnaths present; ven-
tral neuropodial ligule on posterior chaetigers short, up to half length of acic-
ular neuropodial ligule (minimal diagnosis; secondary diagnosis not attained).
Description. Palpophore barrel-shaped, approximately equal width from
base to palpostyle (not overly large compared with palpostyle). Tentacular belt
greater than length of chaetiger 1.
Jaws with dentate cutting edge.
Maxillary ring of pharynx with papillae absent. Maxillary ring paragnaths
present. Area I conical paragnaths present; II conical paragnaths present; III
conical paragnaths present; III conical paragnaths isolated lateral groups ab-
sent; IV paragnaths present; IV conical paragnaths present. Oral ring papillae
present. Oral ring papillae arrangement solitary. Area V papillae present; VI
papillae present; VII-VIII papillae present; VII-VIII papillae arranged in a double
row. Oral ring paragnaths absent.
Dorsal notopodial ligule not markedly reduced on posterior chaetigers.
Ventral neuropodial ligule of anterior chaetigers present. Ventral neu-
ropodial ligule of anterior chaetigers approx. as long as acicular neuropodi-
al ligule. Ventral neuropodial ligule on posterior chaetigers present. Ventral
neuropodial ligule on posterior chaetigers short, up to half length of acicular
neuropodial ligule.
Notoaciculae on chaetigers 1 and 2 absent. Notochaetae: homogomph spin-
igers present. Neurochaetae dorsal fascicle heterogomph spinigers absent;
homogomph spinigers present; heterogomph falcigers in anterior chaetigers
present; on posterior chaetigers present. Neurochaetae ventral fascicle: het-
erogomph spinigers present; homogomph spinigers absent; heterogomph fal-
cigers present; falcigers blade tapering, with straight margin.
Remarks. Wuinereis was established by Khlebovich (1996) for a single spe-
cies formerly placed in Leonnates. The two genera (and also Paraleonnates)
are similar in having only paragnaths on the maxillary ring and only papillae on
the oral ring. Wuinereis can be separated by chaetal and parapodial characters
as per the diagnosis given here. The sole species, W. simplex (Monro, 1939) is
known only from Aldabra Atoll in the Indian Ocean.
125
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Robin S. Wilson et al.: The Nereidid worms
Acknowledgements
We are very grateful to collection managers Melanie Mackenzie and Chris Rowley
(Museums Victoria Research Institute) and Gavin Dally (formerly, The Museum
and Art Gallery of the Northern Territory) for their ever-willing support, to Olga Bir-
iukova (The Museum and Art Gallery of the Northern Territory) for her assistance
with image editing, and to Leon Altoff (Field Naturalists Club of Victoria) and Dr
Dave Cowles (Walla Walla University) for access to photographs of polychaetes
and permission to use them. Dr G.D.F. (Buz) Wilson kindly shared shell scripts for
manipulating Delta output. We are grateful to Dr Masanori Sato, Dr Greg Rouse,
and Dr Nathalie Yonow for comments that helped to improve the manuscript.
Additional information
Conict of interest
The authors have declared that no competing interests exist.
Ethical statement
No ethical statement was reported.
Funding
This study was supported in part by Australian Biological Resources Study Research
Grant RG18-21 to Drs Chris Glasby and Robin Wilson.
Author contributions
Conceptualization: TB, CJG, RSW. Formal analysis: RSW, CJG. Funding acquisition: CJG,
RSW. Methodology: TB, RSW. Writing – original draft: RSW. Writing – review and editing:
TB, CJG, RSW.
Author ORCIDs
Robin S. Wilson https://orcid.org/0000-0002-9441-2131
Christopher J. Glasby https://orcid.org/0000-0002-9464-1938
Torkild Bakken https://orcid.org/0000-0002-5188-7305
Data availability
All of the data that support the ndings of this study are available in the main text or
Supplementary Information.
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Supplementary material 1
Nereididae genera Nexus format
Authors: Robin S. Wilson, Christopher J. Glasby, Torkild Bakken
Data type: nex
Copyright notice: This dataset is made available under the Open Database License
(http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License
(ODbL) is a license agreement intended to allow users to freely share, modify, and
use this Dataset while maintaining this same freedom for others, provided that the
original source and author(s) are credited.
Link: https://doi.org/10.3897/zookeys.1182.104258.suppl1
Supplementary material 2
Nereididae species Nexus format
Authors: Robin S. Wilson, Christopher J. Glasby, Torkild Bakken
Data type: nex
Copyright notice: This dataset is made available under the Open Database License
(http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License
(ODbL) is a license agreement intended to allow users to freely share, modify, and
use this Dataset while maintaining this same freedom for others, provided that the
original source and author(s) are credited.
Link: https://doi.org/10.3897/zookeys.1182.104258.suppl2
Available via license: CC BY 4.0
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All content in this area was uploaded by Robin S. Wilson on Oct 17, 2023
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