CRUSTACEAN RESEARCH，NO 29 ，45-57 ，2000
A new alpheid shrimp of the genus Betaeus n ・omthe Pacific coast of central Japan (Crustacea: Decapoda: Caridea)
Keiichi Nomura and Tomoyuki Komai
Abstrαct.-A new alpheid shrimp， tative of Betaeus from Japanese waters. Betaeus gelasinifer，is described and il ・ The specimens examined in this study lustrated from the Pacific coast of cen- are deposited in the Hayama Siosai Mu- tral Honshu，Japan. The new species is seum，Kanagawa (HSM)，Museum Na- characterized by aset of the following tional d'Histoire Naturelle，Pari s characters: the frontal margin of the (MNHN)，National Fisheries University， carapace is moderately indented; the Shimonoseki (NFU)，Natural History Mu- palm of the first pereiopod is relatively seum and Institute，Chiba (CBM)， deep and usually bears ashallow excava- Nationaal Natuurhistorisch Museum， tion on the ventral surface; the lateral Leiden (RMNH)，and Sabiura Marine surface of the palm of the first pereiopod Park Research Station，Kushimoto lacks granules，tubercles or setae; the (SMP). The abbreviation CLis used for mesial spine at the posterolateral corner carapace length，as measured from the of the telson is noticeably elongate; and anterior margin to the midpoint of the the endopod of the uropod overreaches posterior margin of the carapace. the posterior margin of the telson by 0.3 of its length. It represents asecond spe- Taxonomy cies of the genus from Japanese waters. A briefnote on the taxonomy ofthe genus is Betαeus gelasinifer new species provided. Figs.1-5
Introduction New Japanese name:Ekubo-teppouebimodoki Most ofthe 14 recognized species ofthe genus Betαeus are distributed in temper- Betαeus sp.:Nomura et al. ，1998 :43 ，Fig. 1K. ate waters in the Indian and Pacific Oceans (Table 3) ，though the alpheids are Material examined.-Holotype. generally inhabitants of subtropical or RMNH D 48600，O (CL 6 .3 mm)， tropical regions.Furthermore ，species in Kominato，Boso Peninsula，intertidal ，24 the genus are known to be free living or June 1994，coll .K. Nomura. associated with other invertebrates such Paratypes.MNHN-Na 13605，1o (C L as abalone，sea urchins，and porcelain 4.8 mm)，20vig .
5.8 mm)，Hasama ，Tateyama ，Boso Penin- Antennular peduncle (Figs. 2A-C) sula，intertidal ，18 May 1996，col l. K. relatively robust，about half of carapace Nomura; RMNHD 48601，2 00 (CL 5.5， length，overreaching distal margin of 7.1mm) ，4ovig. <.i? <.i? (CL 5.3-7.1 mm)， blade of antennal scaphocerite.Stylo- Kominato，Boso Peninsula，intertidal ，10 cerite reaching 0.6-0.9 length of second May 1997，coll. K. Nomura; HSM-Crm- segment，terminating in acute spine; first 0078，male (CL 5.6mm) ，Hayama ，Miura segment with strong subdistal tooth on Peninsula，intertidal ，25 June 1997，col l. ventromesial margin，laterodistal margin K. Hagiwara. produced in triaugular process; second Other material. SMP・1671，2ovig. <.i? <.i? segment 1. 7-2.4 times as long as distal (CL 5.8 ，6.8mm) ，Banda ，Tateyama ，Boso width and 1. 2-1. 6times as long as visible Peninsula，intertidal ，25 May 1998，coll . part of first segment; third segment K. Tsuchiya. subequal to visible part of first segment. Description.-Moderately large al- Lateral flagellum (Fig.1A) shorter than pheid shrimp.Body (Figs .1A ，5) robust. carapace，branches fused for 10-14 ar- Rostrum absent (Fig. 2A). Carapace (Figs. ticles ，shorter ，aesthetascs ・bearing 1A，2A ，2B) with 企ontal margin exceeding branch composed of 2-4 articles; mesial anterolateral margin，moderately in- flagellum subequal to carapace length. dented medially; dorsal surface with scat- Antenna (Figs .2A ，B ，D) with basi- tered very short setae;orbital hood well cerite bearing strong ventrolateral tooth， developed，unarmed anteriorly; antero- slightly overreaching distal margin of lateral margin unarmed; pterygostomian first segment of antennular peduncle， angle broadly rounded; cardiac notch dis- anterodorsal margin produced in small tinct. blunt process. Scaphocerite 2.7-3.2times Abdomen (Fig.1A) rounded dorsally， as long as wide; lateral margin nearly four anterior somites with pleura broadly straight; distolateral tooth strong，dis- rounded，that of fifth somite rectangular tinctly overreaching distal margin of posteroventrally; dorsal surface of each rounded blade. Carpocerite subcylindri- somite with sparse very short setae. Sixth cal ，4.0-4.5 times as long as wide，over- somite 0.2-0.3times as long as carapace， reaching distal end of antennular pe- with articulated triangular posteroven- duncle.Flagellum (Fig. 1A) distinctly tral flap; posterolateral process blunt. longer than carapace，stout ，somewhat Telson (Fig. 2J) 0.4 times as long as cara- flattened. pace，1. 7-1. 9times as long as anterior Mandible (Fig.1B) with 2・segmented width; dorsal surface with sparse，very palp，distal segment rounded，with nu- short setae and 2pairs of moderately merous long setae marginally; incisor pro- strong spines，anterior pair arising 仕om cess with 5blunt teeth; molar process midlength; lateral margins nearly paral- with 4clusters of dense short setae on lel in anterior half，slightly convergent in mesial face. Maxillule (Fig.1C) with bi- posterior half; posterior margin strongly lobed palp，lateral lobe narrower than convex，with numerous long setae and 2 mesiallobe，bearing 5long setae，mesial pairs of spines at each posterolateral cor- lobe bearing 1long apical bristle; distal ner，mesial spines much longer than lat- endite subovate，with double row of small eral spines，and exceeding posterior mar- spines and stiff setae on mesial margin; gin of telson . proximal endite slender，with cluster of Eyes (Figs. 2A，B) covered by anterior spiniform setae distally.Maxilla (Fig. lD) part of carapace in dorsal and lateral with short palp; distal endite bilobed， views，fully exposed in anterior view; ocu・ with row of long setae marginally; proxi- lar peduncle with small dorsal spine. mal endite composed of single smalllobe; NEWBETAEUS SPECIES FROM JAPAN 47
A A 5mm
BC 1mm
Fig.1. Betαe u s gehszruhr new species:A，paratype male (CBM-ZC5209，CL6.8mm)，lateral view;B-G，paratype male (RMNH D48601a，CL7.1mm)，right mouthparts:B，mandible;C， maxUlule; i::i， marlIl a; E ，first maxilliped; F，second maxilliped; G ，third maxilliped scaphognathite with anterior lobe nar- proximal endite narrow，with sparse se- rowed distally-First maxilliped (Fig.1E)tae on mesial margin;exopod with n 田 TOW with long，slender palp，overreaching dis- caridean lobe，flagellum long，with nu- tal margin of distal endue;distal endite merous plumose setae distally;epipod with slightly concave mesial margin;large，slightly bilobed.Second maxilliped 48 K 目 NOMURA& T .KOMAI
C D d. B
ABEFGH 2mm
CDIJ 1mm F J
H
Fig. 2. Betα，eus gelαsinifernew species，holotpe male (RMNH D48600 ，CL 5 .9mm ): A ，anterior part of carapace and cephalic appendages，dorsal; B ，same ，lateral ;C ，antennule ，ventral; D ， antenna，dorsal; E ，right first cheliped，lateral ;F ，same ，chela ，dorsal ;G ，same ，merus and is- chium，mesial; H ，left first cheliped，lateral; 1，uropodal exopod，dorsal ，setae omitted; J，telson and right uropods，dorsal ，setae omitted.
(Fig. lF) with dactyl narrow，with dense slightly falling short of or reaching distal setae on mesial margin; exopod long，with margin of antennular pedunde:ultimate numerous plumose setae distally; epipod segment 5.6times as long as deep，taper- suboval. Third maxilliped (Fig.lG) stout， ing distally，with numerous transverse NEWBETAEUS SPECIES FROMJAPAN 49 rows of serrulate stiff setae on dorsal and finger broadly based，terminating in mesial faces ，distal margin with tuft of acute or subacute tip ，crossing with tip of long stiff setae and 0-3 short spines; dactylus; dorsal surface with scattered penultimate segment about half length of short or long setae; lateral face with scat- ultimate segment，with long setae on dis- tered setae and row of numerous tufts of tal margin; antepenultimate segment 1. 5 short to long setae adjacent to cutting times as long as ultimate segment，be- edge; cutting edge in males usually armed coming flat proximally，with sharply with very large tooth just proximal to edged ventromesial margin; basis short， midlength and deep notch just proximal separated 企omantepenultimate segment to large tooth; cutting edge in females and with distinct suture; coxa with promi- part of male with row of low subacute or nent，hooked process arising 企omantero・ blunt teeth insterspersed by thin ridges. lateral angle; exopod well developed，dis- Carpus short，cup-shaped ，with minute tinctly overreaching distal margin of an- setae on surfaces. Merus 1. 5-2.0 times tepenultimate segment; epipod with ter- longer than greatest depth，triangular in minal hook. cross section; dorsal margin bluntly First pereiopods (Fig. lA) usually ridged，produced distally in blunt or sub- equal or subequal，not carried flexed in acute process; lateral face without setae， both sexes.Chelae (Figs .2E-H ，4A- D) ventrodistal angle forming broadly considerably variable in shape and arma- rounded process，ventrolateral margin ture of cutting edges of fingers; 0.7-1. 1 sinuous with strong tubercle proximally; times as long as carapace，1. 9-2.3times mesial face without setae，ventr ，odistal longer than greatest depth; strongly com- angle slightly produced，ventromesial pressed lateral1 y，血 verted，thus dactyl on margin with row of small tubercles and ventral side .Dactylus 0.7-1. 2times as few short setae;ventral surface shallowly long as palm，slightly to noticeably curved concave，without setae .Ischium with dor- dorsally，terminating in acute or subacute sal surface uneven; lateral face unarmed; tip; ventral surface with scattered setae mesial face with small to large tubercle or and few tufts of setae distally; lateral sur- spine arising from midlength of distal face with few tufts of setae distally and margin or unarmed; ventral surface with row of simple long setae or row of tufts of few low tubercles distally or unarmed，but short setae;mesial surface with row of with rows of setae . simple setae or tufts of setae adjacent to Second pereiopod (Fig.3A) overreach- cutting edge; cutting edge in usual males ing distal margin of antennal carpocerite slightly protuberant distally and with few by halflength of dactylus .Chela about 3.5 small，blunt teeth proximally; cutting times as long as wide. Dactylus subequal edge in females and part of male (Fig. 2H) in length to palm，terminating in tiny， with row of low blunt or obtuse teeth in- simple claw; cutting edge sharp.Fixed terspersed by thin ridges. Palm with dor- finger terminating in tiny，simple claw; sal profile slightly sinuous to nearly con- cutting edge sharp，with row of minute vex (including fixed finger) in lateral spinules. Carpus 1. 2times as long as view; dorsal surface bluntly ridged， merus，divided in 5articles ，first article smooth or sometimes with row of low tu- 2.3-2.4 times as long as second article. bercles; lateral face nearly flattened，na - Merus and ischium about 5times as long ked，mesial face convex with scattered as greatest depth. Ischium subequal in short setae，both faces smooth，without length to carpus. granules or tubercles; ventral surface Third pereiopod (Fig. 3B) robust，over- usually with shallow excavation some- reaching distal margin of antennal carpo・ what proximal to base of dactylus .Fixed cerite by length of dactylus. Dactylus 50 K. NOMURA &T .KOMAI
EF 1mm
Fig.3 .Betaeus gelasinifer new species; A-D，holotype male (RMNH D48600 ，CL 5.9mm): A ， second cheliped，lateral; B ，third pereiopod，lateral; C ，forth pereiopod，lateral; D ，fifth pereiopod， lateral. E-F，paratype male (RMNH D48601a ，CL 7.1 mm)，right anterior two pleopods:E ，五 rst pleopod，setae omitted;F ，second pleopod，setae of endopod and exopod omit旬 d.
about 1/ 4-1/3 times as long as propodus， narrowed distally，about 5.0times longer twice length of proximal depth，distinctly than greatest depth; extensor surface biunguiculate，flexor unguis less than with sparse tufts of short setae; flexor half length of di stal unguis. Propodus surface with 8-10 spines arranged in strongly compressed laterally，slightly double row and 2or 3distal spines.Car- NEWBETAEUS SPECIES FROMJAPAN 51 pus about 3.0times as long as deep，be- spiniform setae in distal two-thirds; ap- coming deeper distally; extensor surface pendix interna small，half length of ap- with sparse setae; flexor distal margin pendix masculina. with 1or 2spines. Merus weakly com- Uropod (Fig.21 ，J) with protopod end- pressed laterally，2.8-3.5 times as long as ing in 2dorsal ，po 註lted lobes，laterallobe greatest depth across midlength，with longer than mesial lobe .Endopod over- strong ventr叫 ateral spine arising from reaching posterior margin oftelson by 0.3 slightly distal to proximal margin; dorsal length.Exopod with straight lateral mar- margin slightly convex，with sparse setae. gin，bearing 1or 2large movable spines Ischium unarmed，1. 3- 1. 9times as long just mesial to posterolateral tooth; as distal depth. diaeresis (Fig.2 1) with about 20 small Fourth pereiopod (Fig.3C) similar to fixed spines. third pereiopod in shape and armature， Variation.-This new species exhibits but somewhat shorter，overreaching ante- aconsiderable variation in morphology of rior margin of antennal basicerite by the chelae of the first pair of pereiopods. length of dactylus; flexor surface of pro- Among the 16 examined specimens with podus with 5-9 spines arranged in double intact first pereiopods (six males and 10 row 田 ld 2distal spines; flexor distal mar- females)，13 specimens (four males and gin of carpus unarmed or armed with 1 nine females) have equal or subequal first spine; merus with strong ventrolateral pair of pereiopods，and the remaning spine. Fifth pereiopod (Fig.3 D) shorter three (two males and one female) have than fourth pereiopod，overreaching 田 lt e- distinctly unequal first pereiopods.Re- rolateral margin of carapace by length of garding the armature of the cutting edge， dactylus; propodus laterally or ventrolat- four forms can be categorized as follows. erally with transverse rows of short，日 ne Form A(Fig .4A) :the cutting edge of setae in distal 0.3 ，flexor surface withι6 the dactylus is armed with row of low spines arranged in single row and 1or 2 teeth interspersed by thin ridges; the cut- 出stal spines;carpus and merus unarmed. ting edge of the fixed finger is also armed Branchial formula summarized in with row oflow teeth interspersed by thin Table 1. ridged; there is no hiatus between the Male first pleopod (Fig.3E) with small dactylus and fixed finger. endopod tapering distally to rounded Form B(Fig .4B ):the cutting edge of apex，with several plumose setae; exopod the dactylus is armed with small blunt slender. Male second pleopod (Fig. 3F) teeth and ashallow notch at about the with appendix masculina 5.6times as midlength; the cutting edge of the fixed long as proximal width，0.4 times as long finger bears aprominent notch slightly as endopod，bearing scattered long proximal to the midlength and the re-
Table 1. Branchial formula of Betαeus gelαsinifernew species . Maxillipeds Pereiopods 1 2 3 1 2 3 4 5 Pleurobranch + + + + + Arthrobranch + Podobranch Setobranch + + + + + Epipod + + h h h h h Exopod + + + h: hook-like epipods 52 K. NOMURA &T .KOMAI
B
C D
Fig. 4. Four forms of chelae of first pereiopods of Betaeus gelasinifer new species: A ，SMP-1671 (ovi g.female ，CL 5.8 mm); B ，RMNH D 48601e (ovig. female，CL 6.1mm) ;C ，CBM-ZC 5209a (male ，CL 6.8 mm ); b ，RMNH D 48601a (male，CL 7.1mm) . maining margin is armed with arow of females，nine have the combination AA， low teeth; there is asmall hiatus between and one has the combination AB.From the dactylus and fixed :fmger. the specimens available for examination， Form C(Fig. 4C):the cutting edge of it is suggested that this new species nor- the dactylus is slightly protuberant dis- mally has equal first pereiopods 田 ld that tally and bears afew blunt teeth proxi- the armature of the chela is sexually di- mally; the cutting edge of the fixed fi. nger morphic. The female (RMNH D 48601e; is armed with aprominent blunt tooth CL 6.1mm) appears to be rather ab- and adeep notch just proximal to the berant，because it has the combination large tooth; there is aprominent hiatus AB. Regarding the male specimens with between the dactylus and fixed finger. unequal chelae，there is apossibility that Form D (Fig. 4D): the cutting edge of the smaller chela (form A) may be in the the dactylus is slightly protuberant dis- process before changing to the adult form tally and bears afew blunt teeth proxi- (form C). It is recommended to examine mally; the cutting edge of the fixed finger more abundant specimens to evaluate the is armed only with afew small teeth morphological variability ofthis species. proximally，lacking tooth or notch; there Thepresence or absence of an excava- is aprominent hiatus between the dacty- tion on the ventral surface of the palm of lus and fixed finger. the first pereiopods also shows variation The relation between the combination (Table 2). In males，the excavation is ab- of the forms of the chela and size (indi- sent 企omsmaller chela (Form A) only in cated by the carapace length) is summa- the case of unequal condition.In females， rized in Table 2.Among the six male the presence or absence of the excavation specimens，three have the combination is quite variable as shown Table 2. CC，two have the combination AC; and Measurements.-Both sexes reach up one，the largest specimen (CL 7.1mm) to CL7 .1mm and about 20.0 mmin total has the combination DD.Among the 10 length. Table 2. Relation between size and morphology of the first chelae of Betaeus gelαsinifer new species .
Specimens No. Sex CL(mm) Size of left and Form of chela 1) Excavation on ventral right chelae (Relative size) surface ofpalm of 1st chela left right left right MNHN-Na 13605a ♂ 4.8 equal C C + + RMNHD 48601b ♂ 5.5 equal C C + HSM-Crm・0078 ♂ 5.6 unequal A(smaller) C(l arger) + RMNHD 48600 ♂ 5.9 unequal C (l町 ger) A (smaller) + Ezs CBM-ZC 5209a ♂ 6.8 equal C C + + 民E凶叫司 - ___ーーーー D ーーーーーー D ・ー------ーー士------ー- --士ー・ーー MNHN-Na 13605b ovig. ♀ 4.5 equal A A + + ∞回司 CBM-ZC 520ge ovig. ♀ 4.6 equal A A o ∞開日 CBM-ZC 5209c ♀ 4.7 equal A A + '可 FEUZ MNHN-Na 13605c ovig. ♀ 5.2 equal A A 。 RMNHD 48601d O 羽 g. ♀ 5.3 equal A A + + 主馬 SMP-1671b ovig. ♀ 5.8 equal A A NFU530-2-2132 ovig. ♀ 5.8 equal A A + + RMNHD 48601e ovig. ♀ 6.1 unequal A(smaller) B(l arger) + SMP-1671a ovig. ♀ 6.8 equal A A + + CBM-ZC 5209d ovig. ♀ 7.1 equal A A + +
1) See text and Fig.4 口巴品 、 54 K. NOMURA &T .KOM Al
c
Fig. 5.Betaeus gelαsinifernew species: A ，holotype male (RMNHD 48600 ，CL 5.9 mm)，lateral ;B ， sa me，dorsal ，photo by K. Nomu町II汀r司 C ，paratypemale (HMS-Crm-0078，CL 5.6 mm)，lateral ，photo by K. Hagiwara.
Coloration.-Body and appendages of pale olive green. Both specimens bear fine the holotype (Fig. 5A，B )ar euniformly dark orange spots on the dorsal surfaces . transparent orange in life .The paratype Habitat.-In Boso Peninsula，Bet αeus (Fig. 5C; HSM-Crm-0078)is uniformly gelαsinifer was commonly found in the Table 3.Distinguishing characters and distribution of the species of the genus Betaeus.
Species Frontal margin Lateral surface Excavation onv Dactyli of Extension of Diaeresis Pωterior m 訂 gm Di且tribution ofωrapaω of palm of 1st entral surfaceof posterior 3 posterolateral ofuropod of uropodal (Literature) chela palm of 1st pereiopods spine of telson endopod against chela against posterior posterior m 釘担 margin of tel 鉛 n 。ftelson B. sus帥 lis s位。 ngly ∞nvex with brush absent simple not exωeding ? ωu t h 句 ω' u t h e a s t e m Aus仕alia Stimp80n hairs dorsally (Banner &Banner ，1973) B. em81戸 stus slightly indented granulated absent both margins notexωeding sm∞th exωeding Pacific ∞ast of Chile 。I . M .Edw 釘 ds) with t∞th 但olthuis，1952) B. ensensdensIB α>Dvex 宣nely absent simple exceeding seηated exωeding Paαfic 蜘 stofN剖 h A.merica assel denticulated art 196 Gl 但 ， の Z困 者 B gelss. 凶 r indented sm∞th usually present biun思成由te exc鵬必ng seηated exωeding Pacific ∞astofan回 1Japan 同 同 new speCles 町 凶 1 B .grsc. 必!sH 紅 t deeply indented sm∞th absent biunguiculate exceeding serrated exωe必ng Pacific ∞ast of North A.merica 〉 但a此，1964) 同 門 deeply indented granulated obscurely 出 exωe ng 句、 B .grsnulimanus abωnt ∞texceeding 品1 必 Jap叫K o r e a，China Yokoya biungt且.cula旬 m回 凶 σo k o y a ，1927 ;Mi ya，1972) h ω同M 総 A 問 B. h81プ'o rcfi・依ingsley) indented sm th absent biunguiculate notexωeding 回 reaching Pacific ast of North A.merica 。 ∞ U ∞ 日 m 間 但 art，I964) 一 B.hsrrimsni α>Dvex granulated absent simple exωe， d i n g serrated exaeding Pacific 聞 stofNor也A . m e民 a ω『 Rathbun and spinulated 但art，1964;Jensen ，1995) 同 州 B. Jucundus Bamard slightly nvex with 3small absent simple ? sm th ワ SouthA創ca 。 ∞ ∞ 冨 tubercles (Bam釘 d;1947，1950) 』 〉 M B. 品加seBωc h i slightly ∞nvex granulated absent simple notexωe必ng sm∞th exωeding Atlantic ∞蹴of South A.merica M and spinulated osc 1 〉 (B hi， 9(6) Z B. longidsc似us αm v e x finely absent simple exωeding se 町 ated exωeding P8(蛍 icα 泌 tofNa:制 hAmeri 沼 μlCki時 ωn 自pm叫. a ted 但釘t，1964;Jensen ，1995) B. mscginitiese Hart convex sm∞th absent biunguiculate not exωeding seηated exωedi且g Pacificα 渇st of North A.meril:沼 但 art，1964;Jensen ，1995) slightly indented 耐 B. pingiYu granulated absent simple not exceeding h- 1 reaching Yellow Se a∞ωt ofChina 切白h (Yu，1930) 開 A B. se蜘凶R 泣 t deeply indented pu泌総ent absent biunguic叫a旬 exceeding 開 exae必ng Pacific ast ofNor erica m U ∞ 也A . m 但釘t，1964;Jensen ，1995) B truncstus Dana α>Dvex granulated absent simple not exceeding sm∞th reaching Pacific and Atlantic ∞ast of South America olthuis 1952;Bωchi 1鈍 6) (H ， ， 口、 口、 56 K. NOMURA &T .KOMAI back of rock crevices in the intertidal the posterolateral corner of the telson ， zone，where it was emersed at low tide ， which overreaches distinctly the posterior and usually occurred in male-female margin of the telson. The endopod of the pairs. The congeneric Betαeus granuli- uropod overreaches the posterior margin mαnus sometimes occurred sympatri- ofthe telson by the 0.31ength in the new cally ，but it seem to prefer cryptic habi- species，rather than about 0.11ength in B. tats under 1訂 ge stones or boulders in tide hα rfordi. Theless deeply indented 仕ontal pool. The new species was also observed margin of the carapace distinguishes B. between stones at the intertidal zone near gelαsinifer 企omB.grαcilis 出 ld B. setosus . the mouth of the Hamana Lake，Shizuoka Further，B .setosus is easily separated Prefecture (M. It oh，personal communica- from the new species by the densely se- tion) .This location was in an estuary. tose carapace，antennae and pereiopods. Distribution.-So far known only 仕om Although two nominal species，B. Hamana Lake，Miura and Boso Penin- yokoyαiKubo ，1936 ，and B .mur α.yαm αi sula，the Pacific coast of central Honshu， Yokoya，1936 ，were described from the Japan .These locations are in the warm Pacific coast of central Japan，Miya temperate region. (1 972) concluded that they were s戸l O ny- Etymology.-The specific epithet is a mous with B. grαnulimαnus. Weagree combination of the Latin words，gel αstnus with Miya's opinion. (= dimple)and fero (= bear)，in reference Thetaxonomic position ofthe two taxa to the characteristic excavation on the described from the Far East Russia， ventral surface of the palm of the first Betαeus levifrons Vinogradov，1950 ，and chela. B. vl αdivostokiensis Vinogradov，1950 ，re- Remarks.ー The genus Betαeus is rep- mains unclear，because the original de- resented by 14 recognized species，the dis- scriptions of these taxa are too brief to tinguishing characters and the distribu- provide adequate information for estab- tion of these species are summarized in lishing specific identity.However ， Table 3. The indented frontal margin of Betαeus levi斤ons is clearly different 企om the carapace links Betαeus gelasinifer to B. gelαsinifer in having aconvex frontal the following six species: B .em αrginαtus margin of the carapace. Moreover，there (H. M .Edwards ，1837) known 企omChile; is apossibility that B .vladivostokiensis B. hαrfordi (Kingsley，1877) 企omCalifor- might be actually referred to the genus nia to Mexico;B. granulimαnus Yokoya， Alpheus because of the presence of the 1927 from Japan，Korea and China; B. distinct rostrum and the well developed pingi Yu，1930 from the Yellow Sea coast orbital hood on the carapace. of China; B. gracilis Ha此， 1964 仕omCali- fornia;B .setosus Hart，1964 仕omBritish Acknowledgements Columbia to California.The usual pres- Wewish to thank K. Hagiwara ofMa- ence of ashallow excavation on the ven・ rine Biotechnology Institute Kamaishi tral surface of the palm of the first pereio- Laboratory，K. Tsuchiya of Tokyo Fisher- pod appears characteristic of the new spe- ies University，and M. It oh of Shizuoka cies .Further ，the smooth palm ofthe first Prefectural Fisheries Experiment Sta- pereiopod，which is devoid of granules or tion，for providing specimens.We are also tubercles ，immediately distinguishes indebted to C .H. J.M. Fransen of Na- Betaeus gelasinifer 合omB.emαrginαtus ， tionaal Natuurhistor匂 ch Museum for in- B. grαnulimαnus and B. pingi .From B. tensive reading of the manuscript，and to hα rfordi ，the new species differs in having A. Anker of Museum National d'Histoire the much more elongate mesial spine on Naturelle for providing literatures and NEWBETAEUS SPECIES FROM JAPAN 57 useful suggestions. The manuscript was tions of some new species. Proceedings of improved by comments of K. Baba of the California Academy of Science，7: 28- Kumamoto University M. K. Wicksten of 36. ， Milne Edwards，H .，1837. Histoire naturelle Texas A & M University，and two anony- des crustaces，comprenant l' anatomie，la mous referees. physiologie et la classification de ces animaux，2. 532 pp. Roret，Paris. Miya，Y .，1972. The Alpheidae (Crustacea， Literature cited Decapoda) of Japan and its adjacent w a- Banner，D. M. and A. H .Banner ，1973 .The ters .Part l. Publications from the alpheid shrimp of Australia.Parl 1. Th e Amakusa Marine Biological Laboratory， lower genera. Records of the Australian Kyusyu University，3: 23-101. Museum，28: 291-382. Nomura，K.， K. Hagiwara & H. Ikeda，1998. Barnard，K. H.，1947. Descriptions ofnew spe- The alpheid shrimps (Decapoda: cies of South A 企1can decapod Crustacea， Alpheidae) recorded 企omKanagawa Pre- with notes on s戸l O nymyand new records. fecture，on the Pacific coast of central Annals and Magazine ofNatural History， Honshu，Japan. Natural History Report of 11: 361-392. Kanagawa，19: 39-48. (In Japanese with 一一一一， 1950. Descriptive catalogue of South English summary) African decapod Crustacea (crabs and Rathbun，M .J. ，1904 .Decapod crustaceans of shrimp). Annals of the South A 企ican Mu- the northwest coast of North America. seum，38. 837 pp. Harriman Alaska Expedition，10. 210 pp. Boschi，E. E. ，1966. Una neuva especie de Stimpson，W. ，1860. Crustacea macrura. Pars crustaceo decapodo caridea para las aguas VIII of prodromus descriptions animalium costeras de la provincia de Buenos Aires， evertebratorum，quae in expeditione ad Argentina. Physis B ，Ai res 26:83 -88. (with Oceanum Pacificum septentrionalem，a English summary). repubrica federate missa，Cadwaladaro Dana，J. D. ，1852. Crustacea，Part 1，In United Ringgold et Johanne Rodgers Ducibus， States Exploring Expedition during th e observavit et descripsit. Proceedings ofthe years 1838，1839 ，1840 ，1841 ，1842 ，under Academy of Natural Science of Philadel- the command ofCharles Wilkers，U. S. N .， phia: 22-47. 13 .685pp . Vinogradov，L. G .，1950 .[A key to the shrimps， Glassell，S. A.， 1938.New and obscure decapod lobsters and crabs of the Far Eastl . Crustacea from the west American coast. Iz vestiya Tikhookeanskogo Nauchno- Transactions of the San Diego Sciety of Issledovateliskogo Instituta Ribnogo Natural History，8: 411-454. Khozyastva iOkeanographii ，33: 179-358. Hart，J. F. L. ，1964 .Shrimps of the genus (In Russian) Betαeus on the Pacific coast of the North Yokoya，Y .，1927. Notes on two alpheoid America with descriptions of three new shrimps 企omJapan. Journal ofthe C0 1- species. Proceedings of the United States lege of Agriculture，Imperial University of National Museum，115: 431-466. Tokyo，9: 171-175. Holthuis，L. B.， 1952. The Crustacea Decapoda 一一一一， 1936. Some rare and new species of Macrura ofChile.Reports ofthe Lund Uni- decapod crustaceans found in the vicinity versity Chile Expedition 1948-49.Lunds of the Misaki Marine Biological Station. Universitets Arsskri氏， Nyolid Avd.2 ，47: Japanese Journal ofZoology，7: 129-146. 1-110. Yu，S.-C .，1930 .Deux nouvelles crevettes de Jensen，G. C. ，1995. Pacific coast crabs and Chine. Bulletin Societe Zoologique de shrimps.87 pp. Sea Challengers，Califor- France，55:454-463. ma. Kingsley，J. S .，1878. As 戸lopsis of the North American Species of the genusA lp he u s . Addresses: (KN) Kushimoto Marine Park Bulletin of the United States Geological Center，Arita ，Kushimoto ，Wakayama 649・ Survey，4 :189-199. 3514，Japan; (TK) Natural History Museum Kubo， 1.， 1936. Two new littoral macrurous and Institute，Chiba ，955 ・2 Aoba-cho，Chuo ・ crustaceans 企omJapan. Journal ofthe Im- ku，Chiba 260・8682，Japan. perial Fisheries Institute，31: 47-54. Emails: (KN) alpheus.nomura@ni氏y.ne.jp; Lockington，W .N. ，1877. Remarks on the (TK) [email protected] Crustacea ofthe Pacific coast，with descrip-