CRUSTACEAN RESEARCH，NO .28 :153-159 ，1999

Paramunnαrhipis，a new species of asellote isopod () from Japan

Michitaka Shimomura and Shunsuke F. Mawatari

Abstrαct.-Pαr α munna rhipis new fixed with 5%neutralized formalin solu- species，is described from Otsuchi Bay， tion diluted with seawater 田 ld preserved northern Honshu，Japan ，the first record in 70% ethanol. Each individual (in the of the Paramunnidae from Japan. The type series) was dissected on ahollow new species is distinctive 仕omits conge. glass slide filled with glycerin using for- ners in having dorsally located uropods， ceps and fine needles under abinocular and laterally e玄panded lobes of the head microscope. The body was mounted in bearing anarrow ，shallow median notch. glycerin on ahollow glass slide. Separate appendages were mounted in gum-chloral Introduction on aglass slide. Observations were made with alight microscope equipped with a The is one of the largest sub- Nomarski differential interference con- orders in the :about 1800 species trast device. Themeasurements given un- in more than 30 families are reported der “Material examined" indicate the to ・ worldwide (Kensley & Schotte，1996) .In tal length measured from the tip of the Japan，58 species belonging to 14 families head to the posterior end of the are own (Beddard 1885; Richardson k.n ， ， pleotelson. 1909; Thielmann，1910; Birstein，1957; The type-series are deposited in the Matsumoto，1973; Mezhov，1980; Gamo， Zoological Museum，Division of Biological 1983). ong these only seven species in Am ， Sciences，Graduate School of Science， four families are reported from coastal Hokkaido University (ZIHU). waters (Gurjanova，1950; Nunomura， 1975 1976 1985 1999; Gamo 1976 ， ， ， ， ， Pαrαmunnαrhipis new species 1983). Our coastal survey in Otsuchi Bay， Figs.1-3 northern Japan in 1998，yielded anew Material examined.-Otsuchi Bay， species belonging to P αr α munnαG . O. Iwate Prefecture，Japan .Holotype: o ，1. 2 Sars，1866 of the family Paramunnidae mm(ZIHU-01280) ，48 m ，sand ，10 Aug. V loffen 1914. sis the first record of 田吐 ， Thi 1998. Paratypes: 3 ovig. S?， 1. 5mm the family from Japan and is the second ， (ZIHU-01281)，1. 4mm (ZIHU-01282) ，1. 4 species in the genus collected from the mm(ZIHU ・01283)，89 m ，sand ，11 Aug. North Pacific and the fourth record from 1998; 1o ，0.9 mm(ZIHU-01284) ，46 .5m ， the Northern Hemisphere. sand，25 May 1998. Additional specimens: 1ovig. S?， 1. 1mm (ZIHU ・01285)，46.5 m ， Materials and methods sand，25 May 1998; 4ovig. S?， 1. 0-1.4 mm Sediment samples obtained in the field (ZIHU・01286・9) ，89 m ，sand ，11 Aug. by aSmith-M cI ntyre grab were washed in 1998. aplastic bucket，and the suspension was Description.-Male:Body (Fig. 1A) decanted through asieve with apore size twice as long as maximum width. Head of 0.1 mm. The specimens retained were with fan-shaped，broad anterior expan- 154 MSHIMOMURA& S. F. MAWATARI

C

与旦 C D E. F

Fig. 1. P αr α munnαrhipis new species ，A ，C ，E ，F ，holotype; B ，paratype ，ZIHU ・01281; D ， paratype，ZIHU ・01283: A ，male; B ，female; C ，eye; D ，uropod; E ，antenna 1; F，antenna 2. Scales =O.lmm. NEWPARAMUNNA FROMJAPAN 155 sion divided into 2lobes by anarrow ， 2 subequal in length; article 2with shallow median notch; posterior margin setulated scale; article 3half as long as 2， convex between eyestalks. Eyes dorsolat- with setulated scale. Incisor with 4cusps; eral，each with 2ommatidia (Fig. 1C). lacinia mobilis with 6teeth; spine row Pereonites and pleon without dorsal seta. with 4spines; molar process with 0-1 Pereonite 1longest; pereonites 2-7 sub- seta. Right mandible (Fig. 2B) lacking equal in length. Pereonites 1-3 subequal lacinia mobilis. Palp of 3articles: articles in width; pereonites 4-7 slightly nar- 1and 2subequal in length; articles 2and rowed posteriorly. Pereonites 4and 5 3each with setulated scale. Incisor with 5 with slightly rounded corners; pereonites cusps; spine row with 5spines; molar pro- 6and 7with rounded anterolateral and cess with 0-2 setae and 4teeth. pointed posterolateral corners. Coxal Maxilla 1(Fig. 2C) inner ramus dis- plates not dorsally visible on all tally with 3-5 long setae and 4-9 short pereonites. Pleonite sunken into setae; outer ramus with 7-11 distal setae. pereonite 7. Pleotelson heptagonal， Maxilla 2(Fig. 2D) inner ramus bear- slightly wider than long，widest near an- ing 6-7simple setae apically，210ng setae terior margin，posteriorly with 1-4 pairs and 18-22 short setae distally; outer 2 ofteeth. Uropod (Fig. 1D) uniramous，cy- rami with 2-3 simple and 1-3 pectinate lindrical，2 times as long as broad，bear- setae apically. 泊 g4simple ，3 filoplume-like distal setae Maxilliped (Fig. 2E) palp of 5articles; and 1simple proximal seta. article 1broader than long; article 2twice Antenna 1(Fig. 1E) of 6articles; ar- as long and slightly wider than article 1， ticle 1largest ，nearly as long as broad， with 2distomesial setae; article 3equally with 1distomesial seta; article 2half as long and broad as article 2，with 3setae long as 1，with 2setae and 1filoplume- distomesially and 1seta distolaterally; like seta distomesially and 1seta dor- articles 4and 5more slender than articles sally; article 3 shortest，with 1 1-3; endite rectangular，bearing 4setae distomesial seta; article 4longer than 3， 国 ld 2submarginal setae distally，3 spines with 1distolateral seta. Last 2articles of distomesially and 2coupling hooks me- subequal width: article 5longer than 4， sially; epipod ovate，reaching third palp with 1distolateral seta; terminal article article. as long as 5，distally with 1aesthetasc Pereopod 1(Fig. 2F) shorter than and 1long ，4 short setae. pereopods 2-7: basis longest，with 7-10 Antenna 2(Fig. 1F) peduncle of 6ar- truncate projections on dorsal margin，1 ticles: article 1not visible dorsally; article stout spine and 1seta distally; ischium 2widest ，without setae; article 3laterally shorter than basis，with 1stout distal with 2pr 叫 rusions，each with single seta， spine; merus half as long as ischium，with mesially with 3-5 stout spines and 1dis- 3distal setae and 1stout dorsal spine; tal seta; article 4shortest ，with 1distal carpus widest，2.5 times as long as merus， seta; article 5twice as long as 4，with 3 trapezoidal，with 2sensory spines，2 setae distal setae; article 6longest ，with 4 and ←8serrate projections all on ventral filoplume-like setae and 5simple setae m 町民 n; propodus ovate，with 2ventral ，2 distally and 2simple setae proximally. dorsal setae; dactylus 1/3 as long as Flagellum of 6-8 articles each with 2-4 propodus，with 2distal setae，1 curved distal setae，about 2times longer than unguis and acute supplementary claw. terminal peduncle. Pereopods 2ー7 (Figs 2G-H，3A-C) Left mandible (Fig. 2A) consisting of subequal in shape and length; basis long- palp，incisor and molar processes，lacinia est ，with 1-2 dorsal and 1-2 ventral se- mobilis and spine row. Palp articles 1and tae; ischium shorter than basis，with 3-4 156 MSHIMOMURA &S .F. MAWATARI

A B C

A-F G-1

Fig.2 .Paramunna rhipis new species，A ，E-I ，holotype; B-D，paratype ，ZIHU-01281: A ，right mandible; B ，left mandible; C ，m ax:i lla 1; D ，m ax:i lla 2; E ，m ax:i lliped; F ，pereopod 1; G ，pereopod 2; H ，pereopod 3; 1，pereopod 4. Scales =0 .1mm . NEWPARAMUNNA FROMJAPAN 157

G F H

.'・

A-H ム一一 Fig.3. Paramunna rhipis new species ，A-F ，holotype; Gー1，paratype，ZIHU ・01281: A ，pereopod 5; B ，pereopod 6; C ，pereopod 7;D ，pleopod 1;E ，pleopod 2;F ，pleopod 3; G ，pleopod 4;H ，pleopod 5; 1，operculum. Scales =0 .1mm . setae; merus trapezoidal，half as long as setae and 1filoplume-like seta on dorsal ischium，ventrodistally with 1long seta margin，3-4 setae on ventral margin; and 1-2 short setae，1-2 dorsodistal se- propodus as long as carpus，dorsodistally tae; carpus as long as ischium，with 1-3 with 2setae and 1filoplume-like seta，1 158 MSHIMOMURA &S. F.MAWATARI ventromesial seta，1 ventrodistal sensory pereonites，uropod lacking peduncle，an- spine; dactylus shortest，with 3setae ，1 tenna 2shorter than body，article 3of ar ト curved unguis and minute supplementary tenna 2longer than broad，3・ articulated， claw. reduced mandibular palp，出 ld cylindrical ， Pleopod 1(Fig. 3D) with triangular lat- truncated molar process. eral expansion at three-quarter length， Thebilobed head links the new species half as wide as long，bearing 4setae on to P αr α munnαbilobatαa n d P. integrα each lateral tip; posterior margin obtuse- Nordenstam，1933 from the Antarctic ly pointed，with apair of setae distally. (type locality) and Magellanic region Pleopod 2(Fig. 3E) protopod broad， (Winkler，1994). Paramunnαrhipis is dis- with setose，rounded lateral margin; tinguished from P .bilob αt αb y the follow- endopod surpassing protopod，with slen- ing features (those of P. bilobαt αi n p a r e n - der，curved second article; exopod stout. theses): the head having alobe expanded Pleopod 3(Fig. 3F) endopod with 3 anterolaterally (not expanded)，with a stout plumose setae on apex; exopod of 2 narrow and shallow notch on the anterior articles narrower than endopod; article 2 margin (broad and deep)，1-4 teeth on with 1terminal seta. Pleopod 4(Fig. 3G) each side of the pleotelson (about 12 exopod pointed，reaching distal half of teeth)，and the uniramous uropods on the endopod; endopod 3times as broad as dorsum of pleotelson (biramous on the exopod. Pleopod 5(Fig. 3H) uniramous， distal margin of pleotelson). p αr， α munnα 1. 8times as long as broad. integra differs from the new species in Femαle: 8imilar to male in all pereonal having the head without anterolateral ex- appendages. Body (Fig.1B) widest at pansion，a broad notch on the anterior pereonites 2and 3，1. 8times as long as margin of the head，about 19 teeth on maximum width. Pereonite 1broader each side of the pleotelson，biramous uro・ than head.Pereonites 1-4 subequal in pods on the distal margin of the length; pereo凶 tes 5-7 subequal in length. pleotelson，a lanceolate epipod ofthe max- Operculum (Fig. 31) ovate，1. 2times as illiped ，and avery long endopod of male long as broad，lateral margins rounded， pleopod 2. setose . Etymology.-The specific name is a Remarks.-Pαr， α munnαi s the largest noun in apposition from the Greek genus in the Paramunnidae，now contain- (= fan) ，alluding to the fan-shaped head ing 25 species，22 of which occur in the characteristic of the species. southern hemisphere (Kussakin，1988; Kensley & 8chotte，1996). Theother three Acknowledgments species have been reported from the Wethank the sta町ofthe Otsuchi Ma- northern hemisphere: P αr α munnαbi ・ rine Research Center，the University of lobαt αG . O . 8 訂 s，1866 仕omNorway (G. Tokyo，for providing facilities. Thanks are 0.8訂 s，1866，1897) ，Ireland (Tattersall， also due to Messrs. Tetsuya Kato and 1905) and Iberian Peninsula (Reboreda & Hiroshi Kajihara，Hokkaido University， Urgorri，1995); P. ぞypicαT a t t e r s a l l ，1905 for their help in the field. Weare grateful from Ireland (type locality); P. quαdrati- to Dr. Keiji Baba ofKumamoto University 斤.ons Iverson & Wilson，1980 from Cali- and Dr.Gary C. B. Poore ofthe Museum fornia (勿 pe locality) . of Victoria，for their comments on the The following features displayed by manuscript. the new species indicate that it belongs to Parαmunnα: ovate body，lateral project- Literature Cited ing tergal plates of pereonites，coxal Beddard，F. E.，1885. Apreliminary notice of plates hidden in dorsal view on all the Isopoda collected during the voyage of NEWPARAMUNNA FROM JAPAN 159

H. M. S.Challenger ，part 2，Munnopsidae . 284. Proceedings of the Zoological Society of Nunomura，N. ，1975 .Marine Isopoda 企omthe London，91 6-925. rocky shore of Osaka Bay，Middle Japan Birstein，J. A.，1957. Certain peculeaities of (1). Bulletin ofthe Osaka Museum ofNatu- the ultra-abyssal fauna at the example of ral History，29: 15-35. the genus Storthyngurα( C r u s t a c e a ，Iso- 一一一一， 1976.Marine Isopoda from the rocky poda，As ellota). Zoologicheskii Zhurnal，36 shore ofOsaka Bay，Middle Japan (2). Bul- (7): 961-985. letin ofthe Osaka Museum ofNatural His- Gamδ，S. ，1976. Heterosignum mutsuensis 旬 η ，30: 19-26. gen. nov.，sp. nov.，a new Isopod Crustacea 一一一一， 1985. Marine isopod in the 企omMutsu Bay，Northern Japan (Parasel- coast ofToyama Bay. Memoirs ofthe Natu- loidea，Munnidae). Proceedings of the ral Science Museum，Tokyo ，18: 122-139. Japanese Society of Systematic Zoology， 一一一一一' ， 1999.Sea shore isopod crustaceans col- 12: 39-45. lected 企omIzu Islands，Middle Japan. Bul- 一一一一、 1983. Some species of abyssal asellote letin ofthe Toyama Museum，22: 7-38. isopods (Crustacea) 仕omeast ofthe Japan Reboreda，R. & Urgorri，V. ，1995. New data Trench，with the descriptions of Janirellα about isopods (Crustacea: ) at (Jα，nirellαj α culeatαs p . nov. Science Re- the northwest of the Iberian Peninsula ports of the Yokohama National Univer- coast. Graellsia，51 (0): 129-141. sity ，Section 2，Biology and Geology，30 :1- Richardson，H. ，1909. Isopods collected in the 18. northmost Pacific by the U. S. Bureau of Gurjanova，V. E. ，1950. K faune ravonogich Fisheries Steamer “Albatross" in 1906. rakov (Isopoda) Tichogo okeana 5.Isopod Proceedings ofthe United States National po sboram Kamchatskoi morskoi stasii Museum，37 (1701): 75-121. Gosudarsevennogo gidrologi schskogo in- Sars，G. 0.，1866. Beretning om en 1Som- ta. Akademiya Nauk S. S. S. R. Zool- meren 1865 foretagen zoologisk Reise vid ogischskii Instituta，Isseldovaniia dal Kysterne af Christianias og Christians- Nevostochnykh Morei S. S. S. R. ，2: 281- sands Stifter. Christiania，84-128. 292. 一一一一， 1897.An account of the Crustacea of Iverson，E. W. & Wilson，G. D .，1980. Pαr α ー Norway with short descriptions and figures munnαquαdrαtifrons ，new species，the of all the species. Vol. 2. Isopoda.Pa 此s5， first record ofthe genus in the north Pacific 6. Idotheidae，Arcturidae ，Asellidae ， Ocean (Crustacea: Isopoda: Pleurogoni- laniridae，Munnidae. Pp.81-116 ，pls 33- idae). Proceedings ofthe Biological Society 48. Bergen Museum: Bergen. 270 pp. ofWashington，93 (4): 982-988. Tattersall，W. M .，1905. The marine fauna of Kensley，B .& Schotte M .，1996. World List of the coast ofIreland. Part 5. Isopoda. Scien- Marine and Freshwater Crustacea Iso- tific Investigations for 1904，Fisheries poda. In: Home page ofNational Museum Branch，Ireland ，53-14 1. of Natural History Smithsonian Institu- Thielmann，1910. Beitrage zur Kenntnis der tion. Isopodenfauna Ostasiens. Abhandlungen. Kussakin，O. G.，1988. Marine and brackish- Akademie der Wissenschaften water Crustacea (Isopoda) of cold and tem- Mathematischen-Physikalische Klasse in perate waters ofnorthern hemisphere.Vo l. Munchen，2 (3): 1-109. 3，Suborder Asellota Part 1. Opredeliti Vanhりffen，E .，1914. Die Isopoden der Faune S. S. S. R. (Academy of Science，U. S. Deutschen Sudpolar-Expedition，1901- S. R.， Leningrad)，152: 1-500. 1903. Deutsche Sudpolar-Expedition 1901- Matsumoto，K.， 1973. Isopoda.In: Ueno. M.， 1903，15 (7) ，449-598. The late Tamiji Kawamura，Freshwater Winkler，H .，1994. Paramunnidae (Crustacea: Biology of Japan，473 -488. Isopoda: Asellota) from the Magellan Mezhov，B. V.，1980. Onthe fauna ofIsopoda Strait. Zoological Journal of the Linnean (Crustacea) of the Japanese and Idzu- Society，110 (3): 243-296. bonin Trough of the Pacific. Zoologicheskii Zhurnal，59 (6): 81ι829. Nordenstam，A.， 1933. Marine Isopoda ofthe Address: Division of Biological Sciences， families Serolidae，Idoteidae ，Pseu- Graduate School ofScience，Hokkaido Univer- didotheidae，Ar cturidae，Parasellidae and sity，Sapporo 060-0810，Japan. Stenetriidae mainly 企omthe South Atlan- E-mails:(MS)[email protected]; tic. Further Zoological Results ofthe Swed- (SM) [email protected]. ac.j ish Antarctic Expedition 1901-1903，3: 1-