A new species of the genus Aega (Crustacea Isopoda) from the sea off Okinawa
journal or
publication title
Bulletin of the Toyama Science Museum
number 12
page range 19‑22
year 1988‑10‑31
URL http://repo.tsm.toyama.toyama.jp/?action=repos
itory̲uri&item̲id=557
ANewSpeciesoftheGenusA a(Crustacealsopod漣
fromtheSeao征Okinawa*
NoboruNunomura TovamaScienceMuseum
グソクムシ科等脚目の一新種、A2grzg狸加彪()α"αの記載
布 村 昇
富山市科学文化センター沖縄本島糸満市沖から採集されたグソクムシ科(甲殻類、等脚目)の1種を新種A電、
g増"I彫0 j〃(和名:メダマグソクムシ)として記載した。本種は北大西洋から知られてい るA2gnひ かりsαCarsと類似するが(1)腹尾節各節が広いこと(2)尾節の先端が丸い こと、(3)両複眼が大きく、また接していること、(4)胸節基板があまり、発達しない こと(5)第一触角が短いこと、(6)第二触角が長いこと、(7)オスの第二腹肢の交尾 針がまつすぐに伸長すること等によって区別される。
Someaegidspeclmenswerecollectedinthesea,offltoman,Okinawalsland,Southern lnandtheyweresenttomebythecoutesyofDr.H、Sekiguchi,MieUniversity,Thenar
Japanandtheyweresenttomebymecou[esyoIur.r1.Delfl8uc111,lvLにLノ111vc1・lLy,皿に↓』
thecloseexaminationsofmine,theyprovedtoberepresentanewspeciesbelongingtothe
genusA2g"・
Beforegoingfurther,IwishtoexpressmyslnceregratitudetoDI−、Hideo、Sekiguchifox‐
o f f e r i n g m e t o e x a m m e s u c h i n t e r e s t l n g s a m p l e s .
Aegag〃α肥teoc邸Iasp.、0V.
(Jap,name:Medama‑gusokumushi,new)
Figs,land2
〃"たγ/α/9m"z伽 :5伊訊(l3holotype,16.8mminbodylengthand4ざ'3paratypes,
121〜162mminbodylength)andlギ(allotype,10.3mminbodylength),fromtheseaoff ltoman,40mindepth,Okinawalslandcoll・HideoSekiguchi,July,1985.Typeseriesis depositedasfollows:holotype(TOYACr‑7647),allotype(TOYACr‑7648)and2paratype (TOYACr7649〜7650)attheToyamaScienceMuseum,aparatype(OMNH−Ar3254)atthe OsakaMuseumofNaturalHistoryandaparatype(NSMT−Cr9388)attheNationalScience
Museum,Tokyo・
Descγゆ加兜:Bodyovate,29timesaslongaswide、Pleonnotmuchnarrowerthan
p e r e o n , E y e s v e r y l a r g e a n d c o n t l g u o u s , e a c h e y e c o m p o s e d o f a b o u t l 8 0 o m m a t i d i a 、
Anteriormarginofcephalonnotproducedaremarkablerostrum.
*ContributionsfromtheToyamaScienceMuseum,No.7も;
19
NoboruNunomura
6Jr
識
〈
=Fig.1Aggzzgzgrz郡 〃sp・nov.
A、Dorsalview;B・Mandible;C、OuterlobeofmaxiⅡule;DMaxillaiEMaxil‐
liped;F・Penes;GPleopodl;H,Pleopod2(All:Holotypemale).
Antennule(Fig.2A)withpeduncularsegmentlalmostsquare;segments2and3
r e c t a n g u l a r ・ F l a g e l l u m c o m p o s e d o f l 3 〜 l 4 s e g m e n t s 、
Antennta(Fig2B),reachingthemiddlepartofthe5thpereonalsomlte,Flagellum
composedof30ommatidea、
Mandible(FiglB).Parsincisivastrongandcomposedofasingletooth;lacinia mobiliscomposedof5smaⅡspines,Palpcomposedof3‑segmented;segmentloblong, segment2slightlyaslongasthelst;segment30,7timesaslongasthesecond,bearingabout
l9spinesonoutermargln・
Maxillule(Fig.1C);outerlobewith8teethatthetip・
Maxilla(FiglD);ilmerlobenarrowwith3spines;outerloberatherstoutandwith5
一
、 /
イダダ一二札/く
「
L琴一一一
︑一一
一一
〜
I 聯
Fig.2.A増ngZgzz〃/ /αsp・nov・
AAntennule;B・Antenna;CI・Pereopodsl 7;J・Uropod(All:Holotypemale》。
robustsD1nes、
Maxilliped(Fig.1E);enditesmall・Palpwelldevelopedand4‑segmented
Pereopodl(Fig.2C);basisoblong;ischiumtriangular;merusrectangularwith2spines
oninnermargm;carpusshort;propodusanddactylusformasubchelateform、
Pereopods2and3(Fig.2D−E);basisoblong;ischiumtrlangular;merusrectangular with2〜4spines;carpussquareandsmall;propodusanddactylusformsasubchelateform・
Pereopods4〜7(Fig.2F‑1)ambulatoryandincreasinginlengthposteriorly;basisstout;
ischiumoblongandtapermgtowardthedistalend;merusrectangularandshorterthan ischium;carpusrectangularbutnarrowerthanmerus;dactvlussimDle・
Penes(Fig.1F)pairedandswolleninapicalpart,
Pleopodl(Fig.1G);basisrectangularwithl3couplinghooksjbothramibroadand lanceolate・
Pleopod2(Fig.1H);basisrectangularwithllcouplinghooks;innerramibroadand
21
NoboruNunomura
lanceolatewithshortandnarrowstylus;exopodalsobroad‑lanceolate・
Uropod(Fig.2J)basislong;endopodbroadlanceolatewithaseriesofmarginalspines亘 exopodnarrow、
Re" 7ヵs:ThepresentnewspeciesismostcloselyalliedtoA電pzノg犯かOsaCarscollected fromNorthemAtlanticOcean,buttheformerlsseparablefromthelatterinthefollowing features:(1)widerpleonites,(2)roundedtipofpleotelson,(3)biggerandcontlguouseacheye (4)lessremarkableepimeraofallthepereonites,(5)shorterantennule,(6)longerantenna,and (7)straightstylusontheendopodofmale2ndpleopod.
References