Crustacea: Decapoda: Caridea) from Japan

Nat. Hist. Res., Vol.3 No. 2:123-132, March 1995

Vercoia japonica’ a New Species of Crangonid Shrimp (Crustacea: Decapoda: Caridea) from Japan

Tomoyuki Komai

Natural History Museum and Institute, Chiba 955-2 Aoba-cho, Chuo-ku, Chiba 260, Japan

Abstract A third species of the rare crangonid genus Vercoia Baker, 1904, V. japonica sp. no v., is described and illustrated on the basis of a single ovigerous female specimen from off Izu-Oshima Island, Central Japan. No representative of the genus has been recorded from Japan or anywhere in East Asia. The new species is readily distinguishable from the two known congeners, V. gibbosa Baker, 1904，and V. socotrana Duris, 1992, in the abdomen which lacks a median carina on the third to sixth somites. The genus Vercoia is rediagnosed and its phylogenetic position is briefly discussed.

Key words: Decapoda, Caridea, Crangonidae, Vercoia japonica sp. nov., Japan.

Recently Duris (1992) revised the small Ohshima Island, 34。31.7'N, 139°23.2'E, 138- crangonid genus Vercoia Baker, 1904，and rec- 167 m,18 Oct. 1993, dredge, coll.M. Osawa. ognized two species: V. gibbosa Baker, 1904’ Description. Small crangonid shrimp (Fig.1), known from South Australia, Queensland, and with body robust, gibbous and bearing several the Marshall Islands (Baker, 1904; Balss, 1921; carinae. Integument without setae or pubes- Devaney and Bruce, 1987); and V. socotrana cence, minutely densely pitted. Duris, 1992，known only from the type-locality Rostrum (Fig. 2A, B) short and broad, reach- in the Gulf of Aden, western Indian Ocean. Up ing beyond distal end of antennular peduncles; to the present the genus has not been recorded posterior part depressed; anterolateral lobes from Japan or anywhere in East Asia despite rounded, with anterior margins nearly increased scientific activities in coastal to straight; lateral margin posterior to antero- bathyal zones. lateral lobe weakly sinuous, without notch; In October 1993, T/S Shinyo-Maru of the anterior part produced into rather narrow, Tokyo University of Fisheries conducted a elongate median process occupying approxi- survey of the benthic fauna around Izu Oh- mately 0.3 of rostral length, and T-shaped in shima Island in depths of 70-200 m by means transverse section, concave dorsally and with of dredge. The crustacean material contained a sharp ventral carina along entire rostral specimen of a small unusual crangonid, which length, apex pointed, slightly upturned in later- is assignable to Vercoia. Through the courtesy al view. Rostrum continuing posteriorly into of Mr. M. Osawa of the Tokyo University of broad smooth shield-like platform in gastric Fisheries, this specimen was kindly offered for region, bordered laterally by low dorsolateral study and is described here as a new species. carinae (Fig.1);median carina beginning ab- The holotype is deposited in the Natural His- ruptly from level of anterior two-fifths of cara- tory Museum and Institute, Chiba, with a code pace, not subdivided, confluent with somewhat of CBM-ZC. The abbreviation CL is used to elevated posterior area of carapace; dorsolate- indicate the postorbital carapace length. ral carinae extending beyond level of mia- length of carapace, with feebly sinuous dorsal Vercoia japonica sp. nov. margin. Orbits well developed (formed dor- (Figs. 1-4) sally by proximal rostrum, posteriorly and Material examined. Holotype: CBM-ZC 512, ventrally by orbital margin of carapace, and ovig.罕(CL 3.8 mm), Omurodashi, off Izu- anteriorly by stylocerite and antennular pro-

一123— T. Komai

2 mm

Fig.1.Vercoia japonica sp. nov. Female holotype, CL 3.8 mm, lateral and dorsal views, abdomen somewhat damaged. cesses), bearing inner rows of setae on posterior Sixth to eighth thoracic sternites deeply de- and ventral orbital margins; antennal spines pressed, without any median structures; praec- moderately strong. Anterolateral margins oxae of second pereopods fused, forming ven- between antennal and branchiostegal spines tral plate with vertical anterior ridge terminat- concave. Branchiostegal spines moderately ing in strong, anteriorly directed tooth over- strong, slightly overreaching level of ante- reaching articulation of first pereopods. rolateral lobe of rostrum, directed forward, Abdomen (Figs.1,2D) somewhat damaged supported by sharp carina extending to level of especially in second and third somites. First posterior margin of orbit. Hepatic and branchi- somite with anterior and posterior sections al carinae blunt, not terminating anteriorly in separated by transversely concave setose ridge tooth or spine. Ventrolateral area of carapace continuing along anterior margin of pleura, with shallow depression. Pterygostomian distinctly overhanging anterior dorsal section; angle (Fig. 2C) indicated by small spine. Ven- posterodorsal margin not raised; tergite with tral margin of carapace (Fig. 2C) irregularly obtuse median tubercle on posterior section. sinuous with rounded lobes behind base of Second somite separated into two sections by third maxilliped and of first pereopod; anterior blunt transverse carina, anterior section de- lobe produced into dorsally hooked process pressed below; posterior section with no trace with rounded tip. Posterior and posteroventral of median carina; pleuron very broad, slightly border of carapace without row of setae. sculptured. Third somite without median New species of Vercoia

0.5 mm

Fig. 2. Vercoia japonica sp. nov. Female holotype, CL 3.8 mm, various parts. Appendages dissected from left side. A, anterior part of carapace and eye, lateral;B, rostrum, dorsal, left side damaged; C,left branchiostegite，ventral;D, third to sixth abdominal somites, telson, and uropods, posterodorsal or dorsal; E，antennule, dorsomesial;F, same, ventral;G, antenna, dorsal;H, distal part of scaphocerite, dorsal, setae omitted; I’ first pleopod, dorsal; J, second pleopod, dorsal;K, distal part of exopod of uropod, dorsal, setae omitted.

125- T. Komai carina; pleuron with anterior area depressed, end of distal segment; ventrolateral and ven- corresponding to posterior expansion of tromesial angle somewhat produced, latter pleuron of second somite. Fourth and fifth with long setae. Distal segment with anterior somites without median and lateral carinae. margin somewhat produced forward. Dorsal Posterodorsal margin of third somite slightly flagellum stout, consisting of 7 articles, first convex, those of fourth and fifth nearly article not noticeably elongated, distal 5 arti- straight, without median notch. Pleura broad- cles each with tuft of aesthetascs (proximal 2 ly rounded on first and second somites, tufts much shorter) on ventral face. Ventral rounded posteroventrally in third to fifth flagellum short, not reaching distal margin of somites. Sixth somite broadened posteriorly, second article of dorsal flagellum, rigid, in- broader than long, without median carina; completely 2 articulated, with few setae. posterodorsal margin slightly produced poste- Antenna (Figs.1,2G) with stout basicerite riorly as broadly rounded lobe; posterolateral bearing conspicuous process strongly as- process not acute; posteroventral angle slightly cending over articulation with scaphocerite. produced posteriorly, but rounded. Scaphocerite exceeded by antennular dorsal Abdominal sternites depressed, anterior four flagellum, broadly subtriangular with maximal sternites unarmed, fifth sternite with flattened breadth across proximal one-fourth, 0.7 times posteromedian tooth; sixth somite with smooth as broad as long; dorsal surface with sub- anterior sternal plate lacking median pair of median ridge extending from basal articular teeth. knob with basicerite, extending beyond mid- Telson (Fig. 2D)1.8 times as long as sixth length; lateral margin slightly convex, termi- abdominal somite and 1.6 times as long as nating distally in inconspicuous minute tooth anterior breadth; lateral margins somewhat (Fig. 2H); mesial margin broadly rounded; ante- convex on anterior two-fifths, tapering post- rior and mesial margin with plumose setae be- eriorly therefrom. Posterior margin almost coming noticeably longer proximally. Carpo- truncate with 6 plumose, spine-like setae (one cerite subcylindrical, reaching beneath distal at left angle missing). Dorsal surface sulcate one-third of scaphocerite. Flagellum missing. medially, with 2 pairs of small dorsal spines on Mandible (Fig. 3A) slender, divided distally pair of rather obscure submedian carinae, an- into 4 teeth, terminal pair much stronger than terior pair situated at level of midlength of subterminal pair, with obtuse notch. Maxillule telson, posterior pair at level of approximately (Fig. 3B) with palp feebly bilobed and without 0.8 of telson length. setae; distal endite with truncate mesial Eye (Fig. 2A) with well-developed cornea margin bearing 5 strong spines arranged in 2 narrower than eyestalk; eyestalk short and rows, anterior margin with row of long stiff swollen, without anterolateral lobe. setae; proximal endite slightly smaller than Antennular peduncle (Fig. 2E, F) reaching distal endite, with sparse setae on anterolateral nearly to end of rostrum. Basal segment en- margin. Maxilla (Fig. 3C) with palp tapering larged, anterodorsal margin strongly elevated distally to pointed tip, with thick setae dis- over articulation with intermediate segment, tolaterally, inflated basally; endites poorly de- bearing few setae; dorsal surface concave, with veloped; scaphognathite with posterior lobe deep depression obscured by stout setae near elongated, bearing group of very long setae, base; anteromesial angle with long setae. nearly as long as scaphognathite proper. First Stylocerite enlarged, expanded anterolaterally, maxilliped (Fig. 3D) with simple elongated palp reaching distal margin of intermediate seg- bearing row of plumose setae on mesial ment of peduncle, with sharp transverse carina margin, increasing in length proximally; on ventral surface and with rounded sub- exopod with well-developed lash; caridean lobe marginal vertical lobe on anterior part; lateral moderately broad, with convex lateral margin margin angular; mesial margin convex. Inter- bearing row of setae distally; epipod large, not mediate segment short, broad; anterolateral bilobed. Second maxilliped (Fig. 3E) with process strongly ascending, not reaching distal dactyl subrectangular in shape, broader than

一126— New species of Vercoia

0.5 mm C-E

Fig. 3. Vercoia japonica sp. nov. Female holotype, CL 3.8 mm, left mouthparts. A, mandible, inset, distal part; B, maxillule; C, maxilla; D, first maxilliped; E, second maxilliped.

long, bearing dense assemblage of short rected ventromesially; exopod reaching level of plumose setae and 3 long spines proximally on distal one-third of antepenultimate segment, mesial margin; propodus with row of long with well developed lash. setae on mesial margin; exopod with well- First pereopod (Fig. 4C, D) considerably developed lash; epipod well developed, posteri- stout, subchelate, overreaching scaphocerite or margin concave. Third maxilliped (Fig. 4A, by length of half of palm. Palm 2.0 times as B) overreaching scaphocerite by length of ulti- long as maximal breadth, tapering distally in mate segment and half of penultimate seg- lateral view, lateral margin nearly straight, ment, distal 2 segments flat and broad; ultimate mesial margin sinuous, terminating distally in segment 1.8 times as long as broad, distal strong fixed finger; cutting edge slightly ob- margin apparently subtruncate, but with liquely transverse, with submarginal row of minute pointed tip mesially, lateral margin setae ventrally and dorsally. Carpus short, convex, unarmed, mesial margin mostly strai- strongly sculptured by irregular ridges and ght excepting distal part, with stiff setae and depressions, with strong ventrolateral tooth. vertical tracts of strong spines; penultimate Merus slightly excavated ventrally, with prom- segment as long as and slightly narrower than inent subproximal tubercle on ventral face. Is- ultimate, mesial margin with dense stiff setae, chium short, obliquely articulated with merus. lateral margin with 3 long spines, dorsal sur- Second pereopod (Fig. 4E) very stout for face with thick assemblage of long stiff setae crangonid, not reaching level of distal margin basally; antepenultimate segment shorter than of scaphocerite. Dactyl (Fig. 4F, G) stout, taper- 2 distal segments combined, ventral margin ing distally to acute, slightly curved unguis, bearing 2 deep rounded compressed lobes sub- with scattered spines laterally. Propodus (Fig. distally and basally, proximal lobe deeper, di- 4F, G) slightly longer than dactyl, slightly com-

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maxilliped, lateral;B, same, distal two segments, dorsal;C, first pereopod, lateral;E, second pereopod, lateral;F, same, dactyl, propodus, and distal part of carpus, lateral;G，same, mesial;H, third pereopod, lateral; I, fourth pereopod, lateral, dactyl and distal part of propodus lost; J, fifth pereopod, lateral.

— 128— New species of Vercoia pressed, not tapering distally, bearing 1 very Table 1.Vercoia japonica sp. nov. Branchial for- strong spine at distodorsal corner; lateral face mula. with scattered spines; dorsal surface with irreg- Maxillipeds Pereopods ularly arranged spines becoming dense dis- 1 2 3 1 2 3 4 5 tally. Carpus 1.5 times as long as propodus, with 2 long spines at ventrodistal corner. Pleurobranchs — —— 11111 Merus and ischium partially fused, strongly Arthrobranchs — -1 ----- Podobranchs — compressed laterally, maximal depth 0.4 times Epipods + + - length of merus-ischium fused segment; dorsal Exopods + + + margin very slightly convex, with sparse short Setobranchs — plumose setae; ventral margin convex, with 4 widely spaced long spines. Basis short, with 1 ximally. stout plumose setae and 1long spine at subter- Uropods (Fig. 2K) with rami broad, over- minal ventrodistal angle. reaching posterior margin of telson. Exopod Third pereopod (Fig. 4H) very slender, over- lacking diaeresis; lateral margin feebly convex, reaching scaphocerite by length of distal two bearing row of short setae on distal one-third segments. Dactyl very slender, nearly straight, and 1 small distolateral spine (Fig. 2K). End- without patch of subterminal setae. Propodus opod narrower than and subequal in length to slightly tapering distally. Carpus 1.8 times as exopod, noticeable proximolateral expansion long as propodus, subdivided into 2 articles, forming marginal sinuation with concave me- basal article very short. Merus 0.8 times as diate part; dorsal surface with obscure sub- long as carpus. Ischium 1.3 times as long as median carina. Protopod stout, with small pro- merus. Basis very short. Coxa compressed cess at articulation with endopod; postero- laterally. lateral angle rounded. Fourth pereopod (Fig. 41) broken, dactyl and Apices of pleurobranchs directed anteriorly. distal part of propodus missing, but distinctly Branchial formula summarized in Table 1. stouter than third pereopod. Carpus becoming Coloration. No field data are available on the deep distally, with short distodorsal process. coloration in life of the specimen; in preserved Merus 1.5 times as long as carpus. Ischium 0.8 condition, body straw-color entirely; ventral times as long as merus, with few setae on flagellum of antennule with scattered red dorsal margin. spots. Fifth pereopod (Fig. 4J) overreaching level of Habitat. The present specimen was dredged tip of branchiostegal spine of carapace by on a coarse sand bottom mixed with volcanic length of dactyl. Dactyl simple, compressed rubble and shell fragments. The shrimp appar- laterally, slightly curved, 0.4 times as long as ently resembles small rubble, and its resem- propodus. Propodus armed with 4 spines blance may make it cryptic on such a bottom. widely spaced and becoming long distally on Distribution. Omurodashi, off Izu-Ohshima flexor margin. Carpus 0.5 times as long as Island, Izu Islands, at depths of 137-168 m. propodus, becoming deep distally, without dis- Etymology. The species is named after the todorsal process. Merus 1.5 times as long as country where the holotype was collected. carpus. Ischium 0.8 times as long as merus. Discussion Pleopods with enlarged protopods facing outwards; appendices internae absent from all Although Vercoia japonica is quite distinc- pleopods. First pleopod (Fig. 21) with endopod tive, differing markedly from the two known narrow subrectangular, about half length of congeners, Vercoia gibbosa Baker and V. soco- exopod; exopod broad; protopod relatively trana Duris, unusual generic characters, such slender. Second pleopod (Fig. 2J) with endopod as the specialized orbit formed by the anteior somewhat curved outward; exopod very broad, carapace and the antennular peduncle and the almost lacking marginal setae; protopod well-developed but non-chelate second pereo- strongly flattened, becoming narrow pro- pod with a dubdivided carpus, clearly place the

— 129— T. Komai the new species in Vercoia. Vercoia japonica is setae. Fifth thoracic sternite narrow, fused immediately distinguished from both V. gib- with upturned praecoxae of second pereopods, bosa and V. socotrana by the absence of lateral bearing long sternal tooth; posterior 3 thoracic carinae on the posterior part of carapace and of sternites broadly flat or depressed in ovigerous median carinae on the third to fifth abdominal females, but with deep compressed median pro- somite, and by the smooth lateral margin of the cesses in non-ovigerous females and immature supraorbital expansion of the rostrum. On the specimens; first to fifth abdominal sternites other hand, in V. gibbosa and V. socotrana, the each with median tooth in non-ovigerous fe- carapace bears sharp lateral carinae on its pos- males and immature specimens, but unarmed terior half, and the third to fifth abdominal in ovigerous females; sixth abdominal somite somites are provided with distinct median with flat sternal plate. Eye with cornea sub- carinae; the lateral margin of the supraorbital globular; eye-stalk short and swollen. Anten- expansion bears a distinct concavity (Duris, nular peduncle short and stout, with laterally 1992). The absence of the paired sternal teeth expanded stylocerite and peduncular processes on the sixth abdominal somite and the incom- forming anterior part of orbital cavity; dorsal plete fusion of the merus with the ischium in flagellum short and stout, ventral flagellum the second pereopod have not been reported in reduced. Antenna with broad and short scaph- the two congeners. In V. gibbosa and V. soco- ocerite, distolateral angle with inconspicuous trana, the sixth abdominal somite bears a or subacute tubercle; basicerite with prominent median pair of acute teeth situated just anteri- process anterodorsally; antennal flagellum or to the anus; the merus and ischium of the short. Maxillule with palp lacking setae on second pereopod are distinctly articulated. internal lobe. Maxilla without endites; scaph- The discovery of this new species has shown ognathite with posterior lobe not elongate, that the definition of Vercoia given by Duris bearing long setae on posteromesial margin. (1992) includes several characters that now Third maxilliped with distal 2 segments broad- seem to be only of species level significance. In ly spatulate; antepenultimate segment with 2 addition, comparison between the present new ventral expansions; exopod with well devel- species and Duris' account of Vercoia has oped lash; arthrobranch absent. Second pereo- proved that some of characters, which were not pods unusually stout, not chelate; propodus cited in his generic diagnosis, seem to provide with scattered small spines and 1 strong sub- generic significance. Therefore I present a distal spine dorsally. Third pereopod slender; somewhat modified generic diagonosis. carpus with distinct articulation subprox- imally. Fourth and fifth pereopods short; Vercoia Baker, 1904 dactyls simple. Pleopods with protopods and rami strongly flattened; appendices internae Diagnosis (males unknown for all known spe- absent. Uropods with protopod stout, lacking cies). Body short and robust, sculptured with lateral spine; exopod without subdistal articu- obtuse prominences. Carapace as long as deep, lation; endopod with lateral margin strongly with flat frontal region continuing to broad sinuous. rostrum; anterior part of rostrum narrow and T-shaped in cross section with sharp ventral Type-species. Vercoia gibbosa Baker, 1904. carina; orbits well developed; anterolateral Affinities. Vercoia has been compared with region with moderately strong antennal and the genera in which the second pereopod is branchiostegal spines; ventral margin with simple (Holthuis, 1955; 1993; Dardeau and inner hooked process at anterior one-third and Heard, 1983; Christoffersen, 1988; Duris, 1992), obtusely angled about middle; anterior part of i.e., Sabinea Ross, 1835, Prionocrangon Wood- carapace bearing dorsolateral ridge, posterior Mason and Alcock, 1891, and Lissosabinea part possessing at least median ridge. Telson Christoffersen, 1988，since it possesses a non- with 2 pairs of dorsal spines; posterior margin chelate second pereopod. However, the morph- broadly rounded or subtruncate, with minute ological difference of the second pereopod be- posterolateral spines and some stout plumose tween Vercoia and other three genera is so New species of Vercoia great that the importance of the homology of the apparent non-chelate condition shown by Literature Cited these taxa is very questionable. In Vercoia, the Baker, W. H.1904. Notes on South Australian deca- second pereopod is well developed and unusu- pod Crustacea. Part I. Trans. Proc. Rep. Royal Soc. ally robust for a crangonid; the propodus bears South Australia 28:146-161. a strong spine at the dorsodistal angle and Balss, H.1921. Stomatopoda, Macrura, Paguridea small spines elsewhere; the dactyl is subconical and Galatheidea. Results of Dr. E. Mjoberg's Swed- in shape and terminates in a sharply pointed ish Scientific Expeditions to Australia, 1910-13. unguis. Dr. F. A. Chace, Jr., has suggested to me XXIX. Kungl. Svenska Vetensk. Akad. Handl.61 the possibility that the spine at the dorsodistal (10): 1-24. angle of the propodus is the true dactyl, form- Christoffersen, M. L.1988. Genealogy and phylo- ing a degenerate chela, and that the other, genetic classification of the world Crangonidae larger spine, elsewhere termed the dactyl, is an (Crustacea, Caridea), with a new species and new extension of the propodus, with a false basal records for the southwestern Atlantic. Revta. nor- articulation (somewhat as in Psalidopus Wood- dest. Biol. 6(1): 43-59. Mason and Alcock, 1892). The exact homology Dardeau, M. R. and R. W. Heard, Jr. 1983. Crangonid of these spine-like structures may be resolved shrimps (Crustacea: Caridea), with a description of by an ontogenetic study. On the other hand, a new species of Pontocaris. Mem. Hourglass according to the description and figures given Cruises 6(2): 1-39. by Yaldwyn (1960), the second pereopod of Devaney, D. M. and A. J. Bruce. 1987. Crustacea Prionocrangon is moderately stout, and does Decapoda (Penaeidea, Stenopodidea, Caridea, and not show great size reduction; the propodus Palinura) of Enewetak Atoll. In D. M. Devaney, E. and dactyl are simple, without conspicuous ar- S. Reese, B. L. Burch and P. Helfrich (eds.)’ The mature. In Sabinea (two specimens of S. sarsii Natural History of Enewetak Atoll, Vol.2: 221-233. Smith at hand) and Lissosabinea (according to U.S. Department of Energy, Office of Scientific and the description of L. indica given by De Man, Technical Informations. Oak Ridge, Tennessee. 1920), the second pereopod is greatly reduced Duris, Z.1992. Revision of Vercoia Baker (Crustacea: in size; the distal two segments are also simple. Decapoda: Crangonidae). Invertebr. Tax. 6:1437- Therefore, the apparently non-chelate condi- 1457. tion of the second pereopod is less significant Holthuis, L. B.1955. The recent genera of the carid- to evidence the close phylogentic relationship ean and stenopodidean shrimps (Class Crustacea: between Vercoia and these genera. At present, Order Decapoda: Supersection Natantia) with keys unfortunately, I cannot find evidence to phylo- for their determination. Zool. Verh. 26:1-157. genetically relate Vercoia to other crangonid Holthuis, L. B.1993. The Recent Genera of the genera. To resolve the phylogenetic position of Caridean and Stenopodidean Shrimps (Crustacea, Vercoia, a thorough revision of the family is Decapoda) with an Appendix on the Order Am- recommended. phionidacea. 328 pp. Nationaal Natuurhistorisch Museum, Leiden. Acknowledgments Man, J. G. de. 1920. The Decapoda of the Siboga I am especially indebted to Mr. M. Osawa, Expedition, IV: Families Pasiphaeidae, Stylodactyl- Tokyo University of Fisheries, for sending me idae, Hoplophoridae, Nematocarcinidae, Thalassoc- the specimen for study. My deep gratitude is aridae, Pandalidae, Psalidopodidae, Gnathophyli- due to Dr. F. A. Chace, Jr, National Museum of dae, Processidae, Glyphocrangonidae, and Crang- Natural History, Smithsonian Institution, for onidae. Siboga-Exped. 39a3: 1—318, pis. 1-25. reviewing my manuscript with great care. I Ross, J. C.1835. Marine Invertebrate Animals. In J. also thank Dr. S. Naomi, Natural History Ross (ed.)’ Appendix to the Narrative of a Second Museum and Institute, Chiba, for reading the Voyage in Search of a North-West Passage and of a manuscript and making helpful suggestions. Residence in the Arctic Regions during the Years 1829, 1830’ 1831, 1832, 1833: lxxxi-c, pis. B, C. (not seen)

— 131 — T. Komai

Wood-Mason, J. and A. Alcock. 1891. Natural history 日本産Fercom属（十脚目：コエビ下目： notes from H.M. Indian marine survey steamer エビジャコ科）の1新種の記載 "Investigator," commander R.F. Hoskyn, R.N., commanding. Ann. Mag. nat. Hist. Ser. 6’ 8: 353-362. 駒井智幸 Wood-Mason, J. and A. Alcock. 1892. On the results 千葉県立中央博物館 of deep-sea dredging during the season 1890-1891. 亍260千葉市中央区青葉町955-2 Series II’ not.1.Natual history notes from H. M. 伊豆大島沖の水深138-167 mからドレッジにより採 Indian Marine Survey Steamer 'Investigator,' Com- 集された抱卵雌1個体にもとづき，エビジャコ科ルr- mander R. F. Hoskyn, R.N., commanding. Ann. coia属の新種K japonica (新称：カワリヱビジャコ）を Mag. nat. Hist. Ser. 6，9: 265—275, pis.14,15. 記載した.本属には，オーストラリアとマーシャル諸島 Yaldwyn, J. C.1960. Biological Results of the から記録のあるK gibbosa Baker, 1904とインド汗-のア Chatham Islands 1954 Expedition,1:Crustacea デン湾から記録のあるレ：socotrana Duris, 1992の2種 Decapoda Natantia from the Chatham Rise; a deep がこれまでに知られていたが，本新種は第3から笫6腹 water bottom fauna from New Zealand. N.Z. Dep. 節に正中隆起を欠くなどの点で既知種から容另に識別さ Sci. Ind. Res. Bull. 139: 13—53 (plus index of 3 un- れる.本属の改訂を行ったDuris (1992)により本虞の定 numbered pages). 義形質として引用された形質のいくつかが，種レベルの特徴であることが本新種の発見により明らかになった上 (Accepted on 13 October 1994) に，Durisにより引用されなかった形質のいくつかが属の定義形質として有効であることが判明したので，属の標徴を新たに提唱した.さらに，Vercoia属のヱビジャコ科内における系統的位置について論議した.

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