Development of larval and early juvenile penpoint gunnel (Apodichthys flavidus) (family: Pholidae)

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ART & E UATIONS ARE LINKED
476
Q
Development of larval and
early juvenile penpoint gunnel
(Apodichthys flavidus) (family: Pholidae)
Lisa G. De Forest1
Morgan S. Busby2
1 University of Hawaii
Department of Oceanography
1000 Pope Road, Honolulu, Hawaii 96822
2 National Marine Fisheries Service
National Oceanic and Atmospheric Administration
Alaska Fisheries Science Center
7600 Sand Point Way NE
Seattle, Washington 98115-6349
E-mail address (for M . S. Busby, cont act auth or): morgan.busby@noaa.gov
and pencil illustrations of early flex-
ion, postflexion, and juven ile stages.
Matarese et a l. (1989) published an
illustration of a 15.0-mm flexion lar-
va and some characters distinguish-
ing A. flavidus from Pholis spp.
In the present study we describe
development of A . flavidus f rom re-
cently hatched lar vae to newly set-
tled juveniles, including some general
aspects of osteological development.
Larval A. flavidus are compared with
larvae of other pholid species includ-
ed in the genus Apodichthys by Yatsu
(1981, 1985): Xererpes fucorum and
Ulvicola sanctaerosae. This classifi-
cation was not followed by Matarese
et al. (1989) or Watson (1996) a nd
is not followed in the present study.
Th is work will a id in the accurate
identification of A. f lavidus la rvae
The penpoint g unnel (Apodichthys
flavidus) is a member of the per ci-
form family Pholidae. Pholids, com-
mon ly r eferred to as gunnel s, a re
eel-like fishes that inhabit the rocky
intert id al and subtida l reg ions of
the northern oceans and a re oft en
associated with macroalgae, such as
Fucus spp. or kelp (Watson, 1996).
Gunnels are ecologically important
forage fishes that form part of the diet
of birds and commercially important
groundfish species (Hobson and Sealy,
1985; NMFS1; Golet et al., 2000). The
diet of A. flavidus and other pholids
co mpri se s pr i ma r ily ha r pa ct acoid
copepods, gammarid amphipods, iso-
pods, and other crustaceans (Cross,
1981) . Apodichthys flavidus ranges
along the west coast of North A merica
from southern Califor nia to the Gulf
of Alaska (Mecklenburg et al., 2002).
Adult A. flavidus are disting uished
from other pholids by their total ver-
tebral counts, the presence of a thick
1 N MF S ( Na ti on a l Mar i ne F i sheri es
Se rv ice) . 199 8. F inal env ironmen-
tal assessment and reg ulator y impact
review for A mendment 36 to the Fishery
Ma nagement Pl an for the groun df is h
fi sher y of the Ber ing S ea and Aleutian
Isla nds A rea a nd Amendment 39 to t he
Fisher y Manage ment Plan for ground-
fi sh of the Gul f of Alaska to c reate and
manage a forage fi sh specie s cat egory,
76 p. NOA A / NM FS A las ka R egiona l
Of fice P O Box 2166 8 Jun eau , Al aska
99802 -1668.
and grooved first anal spine, a pre-
an al length that i s approxi mately
60% standard length (SL), and a dark
green to light olive coloration (Yatsu,
1981). It is one of the largest phol-
ids (up to 46 cm) and is important in
the live fish trade for both home and
public aquaria (Froese and Pauly2).
In la te wint er to e a rly spr i n g
months (Janua r y−Apri l) , ad ult A.
flavidus spawn in nearshore waters.
A single female lays clusters of de-
mersal, adhesive eggs onto substrate
that a male will guard until hatching
(Clemens and Wi lby, 1961; Wil kie,
1966 ; Marliave, 1975). The eggs are
3 mm in diameter and the incubation
period is approximat ely 2.5 months
(Wilkie, 19 66; Marliave, 1975). Lar-
vae are about 12−13 mm total length
(TL) at the time of hatching, well de-
veloped, and have pig mented eyes,
an elongated body, and very little to
no yolk sac ( Wilkie, 1966; Marliave,
1975). After about 50 days, the larvae
settle as juveniles and are approxi-
mately 25 mm SL ( Marliave, 1975).
Althoug h A. flavidu s reproduction
has been well-studied, there has not
been a complet e des cr iption of l ar -
val development. Wang3 prov ided a
summary of life history information
2 Froese, R., a nd D. Pauly (eds.). 20 04.
Fishbase . World w ide web ele ctron ic
pu bl ic ati on htt p:// w ww.f ish ba s e. or g
[accessed November 20 04] .
in sa mples taken during nea rshore
ichthyopla nkton surveys and in eco-
log ic al s tudie s and wi ll c ont ribut e
to a better understanding of pholid
systematics.
Materials and methods
We examined 58 larval and juvenile
A. flavidus (11.9−42.3 mm) collected
in d ip-ne t surveys by sc ienti sts of
the Alaska Fisheries Science Center
(AFSC; Busby et a l., 2000) and the
University of Washington (UW) from
four site s: Cl a m Ba y (47° 34. 5ʹN,
122°32.5ʹW), Sequim Bay (48°2.3ʹN,
123° 2.0ʹW), Iceberg Point (48°42.4ʹN
12 2 °53 . 3ʹW) , a nd Fr i day Harb or
(48°54.5ʹN, 1230.7°W), all located in
3 Wan g, J. C. S. 19 86 . Fi shes of t he
Sac ramento- San Joaquin e stu ar y and
adjacent waters, Californ ia: a g uide to
the early life histories, 602 p. Technical
Rep ort 9 of the Interagency ec olog ical
study prog ram for the S acrament o- San
Joaqu in Est uar y. [Available from Eco-
log ica l Analysts, Inc. 215 0 John Glen
Drive, Concord, CA 9 452 0.]
Manuscr ipt submitted 22 June 2005
to the Scientific Editor’s Office.
Manuscr ipt approved 24 October 2005
by the Scientific Editor.
Fish. Bul l. 104:476 –481 (2006).

PREFLIGHT GOOD TO GO
477
NOTE D e Forest and Busby : Development of larval and e arly juvenile A podic ht hys fla vidus
Puget Sound, WA, and from
adjacent waters. Specimens
were initially preserved in
3.5% buffered formalin solu-
tio n and lat er transferred
to 70% eth anol ( Busby et
al., 2000). A dissecting ste-
reomicrosc ope wa s used to
exam ine pig mentation, gen-
eral b ody si ze a nd struc-
ture, and to obtain meristic
counts. Morphological mea-
su rement s we re made on
55 suita ble spec imens by
using a digital image anal-
ysis system consisting of a
video camera attached to a
dissecting stereomicroscope
and a computer with image
analysis software. All mea-
surements were taken from
the lef t side of the speci-
men. Standard leng th was
used throughout the study
unless otherwise indicated.
Dur ing flexion stage, noto-
chord length (NL) was mea-
sured and recorded as SL .
Mea s u re ment s i ncl u ded
st a nd a r d l e n g t h , he a d
leng th, eye diameter, body
depth, snout to anus leng th,
and pectoral-fin length, a s
descr ibed by Moser (1996).
To de sc ribe ost eologica l
de vel op men t of A . f l a vi -
dus, w ith emphasis on the
development of the caudal
skeleton, 12 specimens were
cleared and sta ined by us-
ing the technique described
by Po t thof f (19 8 4 ) . T he
term s “unossified precu r-
sor ” or “element ” ar e used
to de scribe unossif ied ele-
ment s that to ok up a lcian
blue stain but not alizarin
A
B
C
D
E
12.0 mm
15.0 mm
19.5 mm
25.0 mm
37.0 mm
Figur e 1
Dev elopmental ser ies o f penpoi nt gunnel (Apodichthys f lavidus) .(A) Ear ly-f lexion
lar va, Clam Bay, 6 Apr il 19 89 (UW 104928); (B) mid-flexion larva (from Mata res e
et al., 198 9) ; (C) late-f lexion lar va, F rid ay Ha rbor, 2 0 Apr il 19 94 (UW 104930); (D)
postf lex ion larva, Clam Bay, 20 April 1989 (UW 104932 ); (E) juvenile, S equ im Bay,
25 April 1989 (UW 104934) . Illust rations by Beverly Vinter.
red-s stain. From the cleared and stained specimens,
stages of larval development were identified from land-
marks of caudal-fin development. Caudal skeletons of
six specimens representing distinct stages were used to
creat e illustrations. Developmental stage terms follow
Kendall et al. (1984) and Neira et al. (1998). The flexion
stage was divided into three additional stages: early-,
mid- and late -f lexion. Early-f lexion beg ins at hatch-
ing, mid-flexion begins with the formation of the for th
hypural and epurals, and late flexion begins with the
development of the fifth hypural and ends with complete
notochord flexion. Nomenclatu re of caudal skeleton ele-
ments follows Fujita (1989).
Results
Morphology
Apodichthys flavidus larvae are approximately 12.0−13.0
mm at hatching and in ea rly flexion sta ge and have
little or no yolk sac present (Fig. 1A). The early-flexion
stage occurs between hatching and 14.0 mm. Mid-flexion
beg ins at approx imately 14.0 mm (Fig. 1B), late-flex-
ion at 17.0 mm (Fig. 1C), and post flexion at 20.0 mm
(Fig. 1D). T ransformation to the juvenile stage occurs
between 2 5.0 m m and 30.0 m m. Juveni les exam ined
range d from 30.1 to 42.3 mm a nd looked like small

478 Fishery Bulletin 104(3)
Table 1
Body proportions of larval and early juvenile penpoint gunnel (Apodichthys flavidus). Values given for each body proportion are
expressed as percentages of sta ndard length (SL) or head length (HL): mean ± standard deviation, and range.
Sample size, standard length,
and body proportion Flexion Postflexion Juvenile
Sample size 33
Standard length (SL) 14.9 ±2.1 (11.9−19.2)
Snout to anus length/SL 62.9 ±1.8 (58.0−66.1)
Body depth/SL 8.3 ±0.9 (6.4− 9.9)
Head length /SL 13.2 ±0.7 (12.1−14.8)
Eye diameter/HL 33.6 ±4.7 (22.3−44.1)
Pectoral fin length/SL 7.6 ±1.2 (5.4−10.2)
adults (Fig. 1E). Larvae are slender bodied throughout
development and bo dy depth increases f ro m 8% SL
during flexion to 12 % SL in juven iles (Tables 1 and 2).
Head, snout-to-anus, and pectoral-fin leng ths are con-
sistent throughout development at approximately 14% ,
63% , and 7% SL, respectively. Eye diameter decreases
from 34% head length (HL) in flexion larvae to 20% HL
in juveniles.
Pigmentation
Early-f lex ion larvae have a few faint melanophores
loc ated dorsally on the head and nap e and a single
melanophore on the isthmus (Fig. 1A). Along the dorsa l
su rfac e of t he g ut , a ro w of lar ge melanophore s is
present —ir regularly spaced anteriorly a nd posteriorly,
regularly spaced medially. Another row of smaller, evenly
spaced melanophores is present along the anterior ½ to
¾ leng th on the ventral sur face of the g ut. A row of
postanal ventra l melanophores (PV Ms) ext ends from
the anus to the caudal peduncle. Generally there is one
PVM per myomere but in many individuals one or more
are missing from the row. In addition, there are small
patches of melanophores a long the dorsal and ventral
marg ins of the caudal peduncle. In mid-flexion larvae,
patches of melanophores on the head, nape, isthmus, and
caudal peduncle are more defined, and a row of internal
melanophores is present above the notochord (Fig. 1B).
These melanophores develop simultaneously. In addition,
the number of melanophores along the dorsal surface
of the gut nearly doubles. The PV Ms in late-f lex ion
larvae are larger and more slashlike (Fig. 1C). During
postflexion, pigmentation previously noted now appears
very faint (Fig. 1D). Juvenile pigmentation resembles
that of adults (Fig. 1E). Most notably, a horizontal streak
of melanophores extends from the snout to the anterior
margins of the eye and continues from the posterior
margin of the eye to the mid-operculum. T he body in
live specimens is a uniform bright green to olive and
has white spots located above the gut and anterior por-
tion of the anal fin. The g ut is generally unpigmented,
18 4
21.9 ±1.3 (20.0 −24.0) 34.2 ± 5.6 (30.1−42.3)
63.3 ±1.2 (61.8−66.1) 63.5 ±1.8 (62.5− 65.2)
9.3 ±0.7 (8.2−10.4) 11.6 ±1.1 (11.2−12.9)
14.1 ±0.7 (12.9−15.5) 16.4 ±1.1 (15.3−17.3)
27.4 ±3.1 (23.5−35.4) 20.0 ±3.9 (15.8−24.8)
7.9 ±1.0 (6.2−10.1) 6.2 ±1.4 (4.9 −7.1)
with the exception of a few very small irregularly spaced
melanophores on the lateral surface.
Ost eology
He ad r eg io n In early-flexion larvae the maxilla, man-
dible, two mandibular teeth, branchiost egal rays, and
cleithrum a re ossified. The premaxilla ossifies duri ng
mid-flexion. The rema ining bones in the head region are
not ossified until the juvenile stage.
Fi ns Unos sified pre cursors of f ive pri ncipal c audal-
fin rays are present at hatching and throughout early
flexion. During mid-flexion, 12 unossified precursors of
pectoral-fin rays and 13 unossified caudal-fin elements
are present, both first appearing at 15.0 mm. Also at
this size, a few faint unossified anal-fin elements are
present in the anter ior portion of the anal finfold, which
are not visible in unstained specimens. Beginning at 17.0
mm, unossified precursors of dorsal-fin spines are first
present in the area of the dorsal finfold above vertebrae
45−50 and then develop anteriorly and posteriorly from
this position. Unossified anal-fin elements are also added
from anterior to posterior. In addition, the scapula, cora-
coid, and radials of the pectoral fin are ossified and the
adult complement caudal-fin elements is present, but still
unossified (13 principal rays and 11 procurrent rays). By
the end of late flexion (about 20.0 m m), elements of the
dorsa l, anal, and pectora l fins finally become ossified
(Table 2). The single spine is the first element i n the
ana l fin to become ossi fied. Pter ygiophores of all fins
are ossified in juveniles and the pectoral- and caudal-fin
rays become ossi fied and branched. The number of fin
elements present at any particular stage and length is
somewhat va riable as we noted slight differences in the
numbers present between our stained and illustrated
specimens.
Ver tebral colum n At hatching, all neural and haemal
spines are present and ossified (Table 2). In addition,
vertebral centra beg in to differentiate from anterior to

479
NOTE D e Forest and Busby : Development of larval and e arly juvenile A podic ht hys f la vidus
posterior during the early- and mid-flexion stages.
At 17.0 mm, the vertebral centra are completely dif-
ferentiated but remain unossified. In juven iles, the
vertebral centra are completely ossified.
Ca ud al s keleton In early flexion larvae, the noto-
chord begins to bend upward and the haemal spine
of the second preura l centrum, the fused parhypural
plus first and second hypurals, and the third hypural
are present (Fig. 2A). Caudal skeleton elements begin
to ossify at this stage, beginning at the base of each.
Ventral elements that develop at mid-flexion are the
haemal spine of the third preural centrum and the
fourth hypural (Fig. 2B). Dorsally, epurals 1−3 and
neural spines of the second and third preural centra
form during this stage. Elements present in early-
flexion are now fully ossified. At the beginning of
late-flexion (about 17.0 mm), a fifth hypural and a
fourth epural are present but not ossified (Fig. 2C).
In the 19.2-mm late-flexion specimen examined, the
third and four th epurals were fused and the first
epural was fused to the neural spine of the second
preural centrum (Fig. 2D). In postflexion la rvae, the
distal margins of hypurals 3−5 a re oriented ver ti-
cally and the first epural separates from the neural
spine of the second preural centra (Fig. 2E). All other
elements in the caudal skeleton have grow n and are
fully ossified. In juven iles, the c auda l fin has the
adult form and the final element, the uroneural, is
present just ventral to the second and fused third
and fourth epurals (Fig. 2F). A ventral caudal radial,
present from mid-flexion to postflexion (Figs. 2, C−E),
is absent in juveniles.
Discussion
Ou r de sc ript ion of A . f lavidus development can
be used to distinguish larvae of this species from
co -occurr ing species of Pholis spp., Apodichthys,
Ulvicola, and Xererpes along the West Coast of the
United S tat es. As w ith U lvicola sanctaerosa e, A.
flavidus does not have a preflexion stage and larvae
hatch at a n advanced developmental state (Watson,
1996). Larval Pholis spp. differ f rom larval A. flavi-
dus by the presence of pelvic fins in the former and
by differences in pig mentation. The melanophores
along the dorsal surface of the gut in Pholis spp. are
more numerous (about 25 vs. about 18 in postflexion
larvae) and closer in spacing anteriorly (Matarese et
al., 1989), and Pholis spp. do not develop an internal
row of melanophores along the dorsal margin of the
notochord. A podichthys flavidus develops a series
of inter nal melanophores along the entire length of
the notochord by the mid-flexion stage. Lar vae of U.
sanctaerosae can be distinguished from A. flavidus by
pigmentation and by the number and persistence of
pectoral-fin rays in postflexion larvae and juveniles.
Larval U. sanctaerosae have fainter melanophores
that a re more irregularly spaced along the dorsal
Table 2
Meristics of cleared and stained larval and early juvenile penpoint gunnel (Apodichthys fl avidus). Counts are of ossi fi ed elements only. Specimens above dashed line
( ) were undergoing notochord fl exion.
Branchi- Neural spines Centra
Standard Dorsal-fi n Anal-fi n Pectoral ostegal Haemal Caudal-fi n
length (mm) spines elements -fi n rays rays abdominal caudal total spines abdominal caudal total rays
12.2 5 50 43 93 44
12.8 5 50 42 92 43
13.4 5 51 45 96 44
14.6 5 52 43 95 42
15.0 5 51 43 94 44
17.0 5 52 42 94 45
19.2 XC I 15 5 50 41 91 44
21.2 XCI I 15 5 50 43 93 45
23.5 XCI I 15 5 51 44 95 45
30.1 XCII I, 39 14 5 51 42 93 45 51 45 96 24
33.2 XCI I, 41 15 5 50 43 93 43 50 45 95 24
42.3 XCI I, 40 15 5 50 42 92 42 50 44 94 24

480 Fishery Bulletin 104(3)
A
D
B E
C F
Figur e 2
Caudal skelet on develo pment of penpoint gu nnel (Ap odichthys f la-
vid us). (A) Ea rly-f lexi on la rva, C la m Bay, 27 Februar y 1995 ( UW
1049 43); (B) mid-f lexion l arva (not e ir reg ularly shape d EP2), Clam
Bay, 10 May 1989 ( UW 10 4937); (C) l ate -f lex ion larv a, Clam Bay, 19
Apr il 1988 ( UW 10 4939) ; (D) lat e-f lexion la rva, Clam Bay, 15 M ay
198 9 (U W 1049 40); (E) postf lexion larva, Fr iday H arb or, 8 April 1993
(U W 104943); (F) juveni le, Ic eberg Point, 18 Ju ly 1963 (U W 018016).
Caudal -f in el ement abbrev iation s: E P= epural; H PU = haema l spi ne,
pre ur al ; HY =hypu ra l; N C=noto chord ; NP U=neur al spin e, pr eural;
PH = pa rhy pu ra l; PU =preur al cen tr a; U = ur os ty le; UN = uron eu ra l;
VCR =ventral caudal radial. Illustrations by L isa De Forest.
surface of the gut than in A. flavidus, and in early- and
mid-flexion lar vae, these melanophores are restricted
to the posterior ¼ to ½ of the g ut. Another distinguish-
ing characteristic is that U. sanctaerosae does not fully
develop pectoral-fin rays and the pectoral fin does not
persist after the juvenile stage. A pectoral finfold is
present during the larval stage of this species; however,
only the uppermost pectoral-fi n rays (6 or 7 vs. 14 or
15 for A. flavidus) partially develop but do not persist,
and the pectoral fi nfold decreases in size during t he
latter part of development. Larvae of Xererpes fucorum
can be distinguished from A. flavidus by the presence
of a preflexion stage and by hav ing fewer total (84−93
vs. 96 −101) and postanal (35−40 vs. 47−52) myomeres.
In addition, during the later stages of development, X.
fucorum has fewer pectoral-fin rays than A . flavidus
(12 vs. 14−15).
Yatsu’s (1985) revision of the family Pholidae placed
U. sanctaerosae and X. fucorum in the genus Apodich-
thys, but this classification was not followed by Mata-
rese et a l. (198 9), Watson (1996), or in the present
study. Larvae of both these species a re quite si milar

481
NOTE D e Forest and Busby : Development of larval and e arly juvenile A podic ht hys fla vidus
to A. flavidus; however, we recommend a more detailed
study of larval U. sanctaerosae and X. fucorum, includ-
ing a description of caudal skeleton development, before
concluding that larval characters do, or do not, support
Yatsu’s (1985) classification. In particu lar, it would be
interesting to investigate whether either species devel-
ops a four th epural that fuses with the third, or a first
epural that fuses with the neural spine of the second
preural centrum during flexion. In another cleared and
stained individual we obser ved fusion of the neural
spines on the third and fourth preural centra (NPU4
and N PU3, Fig. 3D). However, only one speci men of
A. flavidus was examined at each of these fusions and
more specimens, when available, should be cleared and
stained to determine if these fusions occur in all larval
A. fl avidus. P re sence or absence of a ventral caudal
radial may a lso be of interest. Although it is unclear
what becomes of the vent ra l caudal radial betwe en
postflexion and juvenile stages from our study of A.
flavidus, we hy pot hesize that it fu ses w ith the tip of
the haemal spine of the second preural centrum. Tak-
ing a ll of these u nusual aspects of A. flavidus larva l
development into account, we suggest that development
of U. sanctaerosae and X. fucor um should be f ur ther
investigated to clari fy the sys tematic r elationsh ips
among the genera.
Acknowledgments
The author s th an k Theodore Piet sch (University of
Washi ngton [UW ]) for his help, support, and encour-
agement with this project. Beverly Vinter illustrated the
specimens in the developmental series. We also thank
the Ichthyoplankton Laboratory of the Alaska F ishery
Science Center (AFSC) and the U W Fish Collection for
use of their faci lities and spec imens. An n Matarese
(AFSC) and William Watson (NOAA-Southwest Fish-
eries Science Center) reviewed an earlier d raf t of the
manuscript.
Literature cited
Busby, M. S., A. C. Matarese, and K. L. Mier.
2000. A nnu al, seasona l, and diel composit ion of larval
and juvenile f ishes col lec ted by dip-net i n Cla m Bay,
Puget Sound, Washing ton , from 198 5 to 19 95. NOAA
Tech. Memo. NMFS-AFSC -111, 36 p.
Clemens, W. A., and G. V. Wilby.
1961. Fishes of the Pacific Coast of Canada, 2nd ed. Bull.
Fish. Res. Board Can. 68, 4 43 p.
Cross, J. N.
1981. Str uct ure of a roc ky inter tidal fish assem blage.
Ph.D. dis s., 25 9 p. Univ. Washington, Col lege of Fish-
eries, Seattle, WA.
Fujita, K.
1989. Nomenclatu re of cartilagino us eleme nts i n the
caud al skelet on of teleostean f ishe s. Jap. J. Ichthyol.
36:22−29.
Golet, G. H., K. J. Kuletz, D. D. Roby, and D. B. Irons.
20 0 0. Adult pr ey c ho ic e aff ec t s ch ic k g ro w th a nd
reprodu ctive succe ss in p ige on guil lemots. The Auk
117:8 2−91.
Hobson, K. A ., and S. G. Sealy.
1985. Div ing rhy thms and d iu rn al r oo sting times o f
pelagic cor mora nts. Wilson Bu ll. 9 7:116 −119.
Kendall, A . W., Jr., E. H. Ahlstrom, and H. G. Moser.
1984. Early life h istory stages and their characters. In
Ontogeny and sy stematics of f ishes (H . G. Moser, W. J.
Richar ds, D. M. Cohen, M. P. Fahay, A. W. Kendall Jr.,
and S. L. Richardson, eds.), p. 11−22. Spec. Publ. 1, A m.
Soc. Icht hyol. Herp etol. Al len Press, Law rence, K S.
Marliave, J. B.
1975. Th e beh aviora l tr ansfor mation fro m the plank-
ton ic la rval stage of s ome mari ne fishe s rea red i n the
laborator y. Ph.D. diss., 231 p. Univ. British Columbia,
Vancouver, Ca nada.
Matarese, A. C., A. W. Kendall Jr., D. M. Blood, and B. M. Vinter.
198 9. Labor ato ry g uide to early l ife histor y stage s of
northea st Pac if ic fishe s. NOA A Tec h. Rep. NM FS 80,
652 p.
Mecklenburg, C. W., T. A. Mecklenburg, and L. K. Thorsteinson.
2002. Fishes of Alaska, 1037 p. Am. Fish. Soc., Bethesda,
MD.
Moser, H. G. (ed.)
199 6. The early stages of fishes i n the Califor nia C ur-
rent r egion. Cali f. Co op. Oc eanic Fish. Invest. At las
33, 1505 p.
Neira, F. J., A. G. Miskiewicz, and T. Trnski.
1998. Larvae of temperate Australian f ishes: laboratory
guide for larval fish identification, 474 p. Univ. Western
Austra lia P ress, Wester n Australia , Australia.
Potthoff, T.
198 4. Clear ing and stai ning te chn iques. In Ontog eny
and systematics of f ishes (H . G. Moser, W. J. Richar ds,
D. M. Cohen, M . P. Fahay, A. W. Kendall Jr., and S. L .
Ric har dson, eds.), p. 35−37. Spec. P ubl. 1, Am. Soc.
Icht hyol. Herpetol . Al len Press, Law rence, K S.
Watson, W.
199 6. Pholid ae: g un nels. In The early stages of f ishes
in the Cal iforni a Current reg ion (H. G. Mo ser, ed .), p.
1120−1125. Cali f. Co op. Ocea nic F ish . Invest. Atla s
33.
Wilkie, D. W.
196 6. Color pigments in t he penpoint gunnel Apodich-
thys f lavi dus a nd their ecological significance. M.S .
thesis, 14 3 p. Dept. Zoology, Univ. British Columbia,
Vancouver, Ca nada.
Yatsu, A.
1981 A r evi sion of the g unnel family Phol idae ( Pisces,
Blennioidei). Bull. Natl. Sci. Mus. (Tokyo) Ser. A (Zool.)
7:165 −190. [In Japanese.]
1985. Phyl oge ny of t he family P hol idae (B len ni oidei)
with a r edescript ion of Pholis Scopoli. Jap. J. Ichthyol.
32:263−282 .