Bull. Natl. Mus. Nat. Sci., Ser. A, Suppl. 2, pp. 21–24, March 21, 2008

A New Species of Cocotropus (Teleostei: Aploactinidae) fromthe Ryukyu Islands, Southern Japan
Hisashi Imamura1 and Gento Shinohara2
1Fisheries Science Center, the Hokkaido University Museum,
3–1–1 Minato-cho, Hakodate, Hokkaido 041–8611, Japan
E-mail: imamura@museum.hokudai.ac.jp
2
Department of Zoology, National Museum of Nature and Science,
3–23–1 Hyakunin-cho, Shinjuku-ku, Tokyo 169–0073, Japan
E-mail: s-gento@kahaku.go.jp

Abstract A new species of aploactinid, Cocotropus possi, is described based on 2 specimens(32.1–34.5 mm in standard length) collected from the Ryukyu Islands, southern Japan. The newspecies differs from 12 known congeners in having the following combination of characters: XIII,
8 doral-fin rays, 13 pectoral-fin rays, 26 vertebrae, 5 preopercular spines, the upper jaw longer thanthe lachrymal, no fleshy papillae on the posterior portion of the maxilla, no vomerine teeth, manywell-developed fleshy papillae on the ventral surface of the lower jaw, the first sensory pores onboth sides of the lower jaw separate, isthmus tip reaching to level of between fourth and fifth sensory pores of lower jaw, and the body mostly uniformly dark brown.
Key words : Aploactinidae, Velvetfishes, New species, Cocotropus, Ryukyu Islands.

The velvetfishes (family Aploactinidae) inhabit rocky reefs and soft-bottom trawling grounds
in tropical to temperate Indo-Pacific waters(Randall et al., 1990; Kuiter, 1993). The family
contains about 17 genera and about 43 species(Imamura and Shinohara, 2004; Johnson, 2004;Nelson, 2006). Seven species belonging to 4genera (Aploactis, Cocotropus, Erisphex, andKanekonia) occur in Japanese waters (Nakabo,2002; Imamura and Shinohara, 2003).
The genus Cocotropus had been established byKaup (1858) for Corythobatus echinatus Cantor,
1849, and it was recently redefined by Poss(1999) who showed the following diagnostic
characters: gill membranes free from the isthmus; anus slightly anterior to anal-fin origin;doral-fin rays continuous and comprising a singlefin; I, 3 pelvic-fin rays; and interorbital ridges onboth sides running in parallel. At present, 12
valid species are recognized as the members ofthe genus (Imamura and Shinohara, 2003, 2004;Fricke, 2004; Johnson, 2004).
Recently, we had an opportunity to examine 2

unusual specimens of Cocotropus collected fromthe Ryukyu Islands, southern Japan. We herein
describe a new species based on these specimens.
Materials and Methods
Methods for making counts and measurements
follow Imamura and Shinohara (2003). Counts of
unpaired fin rays and vertebrae were based on radiographs. Standard and head lengths are abbreviated as SL and HL, respectively. Where different, values for the paratype follow those for theholotype in parentheses. Cocotropus specimens
used for comparison in this study are listed inImamura and Shinohara (2003, 2004). Institutional acronyms are as follows: NSMT (NationalMuseum of Nature and Science, Tokyo, formerly
called as National Science Museum, Tokyo) andURM (University of the Ryukyus, Okinawa).

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H. Imamura and S. ShinoharaFig. 1. Cocotropus possi sp. nov., NSMT-P 76417, holotype, 34.5 mm SL, Ryukyu Islands, southern Japan (70%ethanol-preserved condition).

Cocotropus possi sp. nov.
(New Japanese name: Higemojya-okoze)(Figs. 1–2)
Holotype. NSMT-P 76417 (ex. URM-P 29793),
34.5 mm SL, Maeda Cape (26°27N, 127°47E), Okinawa
Island, Ryukyu Islands, May 1993 (date unknown).
Paratype. URM-P 35083, 32.1 mm SL, tidepool,West side of Sesoko Island (26°38N, 127°52E), Ryukyu
Islands, 21 Jan. 1996.

Diagnosis. A new species of Cocotropus
with XIII, 8 doral-fin rays, 13 pectoral-fin rays,
26 vertebrae, 5 preopercular spines, upper jaw
longer than lachrymal, no fleshy papillae on posterior portion of maxilla, no vomerine teeth,
many well-developed fleshy papillae on ventralsurface of lower jaw, first sensory pores on bothsides of lower jaw separate, isthmus tip reaching
to level of between fourth and fifth sensory poresof lower jaw, and body mostly uniformly darkbrown.
Description. Doral-fin rays XIII, 8 with ultimate pterygiophore supporting 1 ray (XIII, 7
with ultimate pterygiophore supporting 2 rays);anal-fin rays II, 7 with ultimate pterygiophore
supporting 2 rays (II, 7 with ultimate pterygiophore supporting 1 ray); pectoral-fin rays 13 on
both sides; pelvic-fin rays I, 3; segmented caudal-fin rays 7 (upper)7 (lower); bony sensory tubes
on lateral line 12 on both sides (11 on bothsides); gill rakers 2810 (178); vertebrae
26. Proportions as % SL: HL 36.2 (35.8); snoutlength 9.3 (10.0); orbital diameter 11.0 (11.5);
lachrymal length 11.0 (11.2); upper jaw length
13.6 (13.7); lower jaw length 16.5 (15.6); interorbital width 6.7 (7.2); predorsal length 18.3(19.6); preanal length 65.5 (64.5); length of dorsal fin base 77.4 (75.4); length of anal-fin base20.3 (20.2); length of caudal peduncle 14.8(18.1); depth of caudal peduncle 10.1 (11.5);
pectoral-fin length 30.7 (34.9); pelvic-fin length
14.8 (14.6); length of first dorsal-fin spine 17.1(15.6); length of second dorsal-fin spine 19.4(17.4); length of third dorsal-fin spine 18.3(16.5); length of first anal-fin spine 9.9 (8.7).
Proportions as % HL: snout length 25.6 (27.8);
orbital diameter 30.4 (32.2); lachrymal length30.4 (31.3); upper jaw length 37.6 (38.3); lower
jaw length 45.6 (43.5); interorbital width 18.4(20.0).
Body and head moderately compressed, covered by small pointed papillae, each underlain bytiny buried scale. Anterodorsal profile of headmostly straight. Snout short, 3.9 (3.6) in HL. Eyelarge; its diameter 3.3 (3.1) in HL, shorter thansnout length. Eye with small papillae surround-New Cocotropus from Japan

Fig. 2. Ventral view of head of Cocotropus possi
sp. nov., NSMT-P 76417, holotype, 34.5 mm
SL, Ryukyu Islands, southern Japan. Arrowand numbers indicate anterior tip of isthmus
and sensory openings of lower jaw, respectively.

ing pupil. Interorbital ridges on both sides, ending in a pointed papillae posteriorly, running inparallel. Supraorbital ridge ending in a spine.
Single spine present on parietal, pterotic, andposttemporal. Two blunt suborbital spines ventral
to eye. Two lachrymal, 5 preopercular and 2 opercular spines present; lower opercular spine indistinct. Mouth weakly oblique. Upper jaw 2.7(2.6) in HL, longer than lachrymal length; itsposterior margin well beyond posterior tip of second lachrymal spine. Posterior part of upper jaw
with several small papillae, each underlain by atiny buried scale, but lacking fleshy papillae.
Lower jaw subequal in length to upper jaw whenmouth closed. Upper and lower jaws with villiform teeth. Palatines and vomer lacking teeth.
Many well-developed fleshy papillae on ventral
surface of lower jaw (Fig. 2). Five sensory porespresent on lower jaw; first pores on both sides

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narrowly separated (Fig. 2). Gill membranes freefrom isthmus. Isthmus tip reaching to level of between fourth and fifth sensory pores of lower jaw(Fig. 2). Lateral line slightly arched. Sensory
canals of supracleithrum and first to third bonytubes (supracleithrum, and first and second bonytubes in paratype) on lateral line continuous;
other bony tubes on lateral line separated fromeach other. Ultimate bony tube on caudal-finbase. Anus slightly anterior to anal-fin origin. All
doral-fin rays with papillae. First dorsal-fin spine
slightly shorter than second dorsal-fin spine.
Anal and pelvic fins with several papillae basally.
Pectoral fin 3.3 (2.9) in SL, mostly covered withpapillae except for lower and posterior margins;
its posterior tip just short of origin of anal fin.
Pelvic fin 6.8 (6.8) in SL; its posterior tip notreaching to anus. Caudal fin rounded posteriorly;
about basal one-third (fourth in paratype) of caudal fin with papillae. All soft fin rays unbranched.
Color in alcohol. Head, body, and fins mostly uniformly dark brown. Lateral part of body
medial to pectoral fins with large pale brown
blotch, the center of which with irregular brownmarking. Anus pale. Cheek brown. Anterior margin of snout, upper jaw, anterior portion of lower
jaw, and lower cheek region posterior to upper
jaw pale brown. Interorbital ridges brown (palebrown in paratype). Margins of fins pale brown;
upper and lower portions of caudal fin each witha pale brown blotch. Base of pectoral fin brown,with a pale brown spot. In paratype, middle ofbody with a small pale brown spot dorsally, andupper and lower portions of caudal peduncle witha pale brown area.
Etymology. Named in honor of Dr. Stuart G.
Poss, in recognition of his outstanding contributions to aploactinid systematics.
Remarks. Among the 12 valid species ofCocotropus, C. possi is most similar to 3 congeners, Cocotropus masudai Matsubara, 1943,
Cocotropus roseomaculatus Imamura and Shinohara, 2004, and Cocotropus steinitzi Eschmeyerand Dor, 1978 in having 13 pectoral-fin rays, nofleshy papillae on the posterior portion of the24H. Imamura and S. Shinohara

maxilla, and lacking vomerine teeth (see Imamura and Shinohara, 2003, 2004; Johnson, 2004).
Cocotropus possi, however, differs from them inhaving 13 dorsal-fin spines (vs. 12 in thesespecies) and first sensory pores on both sides ofthe lower jaw separated from each other (vs.
fused in these species) (Fig. 2). Cocotropus possi
is also separable from C. masudai in having theupper jaw longer than the lachrymal (vs. theupper jaw shorter than the lachrymal) and 5 preopercular spines (vs. 4). It differs from C. roseomaculatus in having the body mostly uniformly
dark brown (vs. pale brown), and from C.
steinitzi in having 26 vertebrae (vs. 25) (Imamuraand Shinohara, 2003, 2004; personal observation).
Cocotropus richeri Fricke, 2004 also has 13
pectoral-fin rays and no fleshy papillae on theposterior portion of the maxilla, however thevomerine tooth condition has not been reported(Fricke, 2004). However, C. possi is easily separable from C. richeri in having 8 soft doral-fin
rays (vs. 10), isthmus tip reaching to level of between fourth and fifth sensory pores of the lower
jaw (vs. not reaching to level of fifth pore), andpreserved coloration mostly uniformly darkbrown (vs. pale whitish) (Fricke, 2004).
In addition, C. possi has many well-developed
fleshy papillae on the ventral surface of the lower
jaw (Fig. 2) (all other 12 species of Cocotropus
lack such papillae).
Acknowledgments
We express our sincere thanks to J. W. Johnson(Queensland Museum) for critically reading adraft manuscript and providing important comments. We are grateful to T. Yoshino (URM) for
providing the specimens. D. Catania (California
Academy of Sciences) kindly provided literature.
Finally, we sincerely thank K. Matsuura (NSMT)
for providing us an opportunity to publish thisnew species. This study was supported in part by
a Grant-in-Aid from Japan Society for the Promotion of Science (18570098).

Literature Cited
Eschmeyer, W. N. and M. Dor. 1978. Cocotropus steinitzi,a new species of the fish family Aploactinidae from theRed Sea and Andaman Islands (Pisces: Scorpaeniformes). Israel Journal of Zoology, 27: 165–168.
Fricke, R. 2004. Cocotropus richeri, a new species of velvetfish (Teleostei: Aploactinidae) from Lifou, Loyalty
Islands. Stuttgarter Beiträge zur Naturkunde, Serie A(Biologie), (660): 1–7.
Imamura, H. and G. Shinohara. 2003. Cocotropus keramaensis, a new species of the family Aploactinidae(Teleostei) from the Kerama Islands, southern Japan.
Ichthyological Research, 50: 233–238.
Imamura, H. and G. Shinohara. 2004. A new species of
Cocotropus (Actinopterygii: Teleostei: Aploactinidae),from South Africa, western Indian Ocean. Species Diversity, 9: 193–200.
Johnson, J. W. 2004. Two new species and two newrecords of aploactinid fishes (Pisces: Scorpaeniformes)
from Australia. Records of the Australian Museum, 56:179–188.
Kaup, J. J. 1858. Einiges ünder die Acanthopterygiens àjoue cuirassée Cuv. Archiv fur Naturgeschichte, 24:329–343.
Kuiter, R. H. 1993. Coastal Fishes of South-eastern Australia. University of Hawaii Press, Honolulu. xxxi437
pp.
Matsubara, K. 1943. Studies on the scorpaenoid fishes
from Japan. Anatomy, phylogeny and taxonomy (II).
Transactions of the Sigenkagaku Kenkyusyo, (2):171–486, pls. 1–4.
Nakabo, T. 2002. Aploactinidae. Pages 601–602, 1522 inT. Nakabo, ed. Fishes of Japan with Pictorial Keys tothe Species, English edition. Tokai University Press,Tokyo.
Nelson, J. S. 2006. Fishes of the World, 4th Edition. John
Wiley & Sons, Inc., New York. xix601 pp.
Poss, S. G. 1999. Aploactinidae. Pages 2354–2358 in K.
E. Carpenter and V. H. Niem, eds. FAO Species Identification Guide for Fishery Purposes. The Living Marine
Resources of the Western Central Pacific, Vol. 4. Bony
Fishes Part 2 (Mugilidae to Carangidae). FAO, Rome.
Randall, J. E., G. R. Allen and R. C. Steene. 1990. Fishesof the Great Barrier Reef and Coral Sea. Crawford
House Press, Bathurst. xx507 pp.
Manuscript received 21 June 2007; revised 6 August2007; accepted 31 August 2007.
Associate editor: K. Matsuura.