A new species of the genus Gnorimosphaeroma (Isopoda, Sphaeromatidae) from the mouth of Tonda River, Kii Peninsula, southern Japan

6 Pages·1999·2.4 MB·

A new species of the genus Gnorimosphaeroma
(Isopoda, Sphaeromatidae) from the mouth of
Tonda River, Kii Peninsula, southern Japan
journal or Bulletin of the Toyama Science Museum
publication title
number 22
page range 1-5
year 1999-03-25
URL http://repo.tsm.toyama.toyama.jp/?action=repos
itory_uri&item_id=734
BulletinoftheToyamaScienceMuseumNU22，pp、1−5（1999）
ANewSpeciesoftheGenusG""柳OS加α97℃加α
(Isopoda，Sphaeromatidae）fromtheMouthofTondaRiver
KiiPemnsula，SouthernJapan＊
NoboruMJNOMURA
ToyamaScienceMuseum
l−8−31Nishinakano−machi，Toyama−shi，939−8084JAPAN
『
紀伊半島富田川河口から発見されたイソコツブムシ属の一新種
布村昇
富山市科学文化センター
〒939−8084富山県富山市西中野町1−8−3：
和歌山県白浜町富田川河口から採取された5頭のイソコツブムシ属の標本を新種G"0?γ"2ヶ
sp""り"zα”I〔ﾉﾋzg"s2（和名：トンダガワイソコツブムシ）として記載した。本種は韓国から知
られているG"γj版OSPﾉZα"℃,"αα"c〃α/OsKwonと最もよく類似するが，（1）第2小顎の剛毛数
が少ないこと，（2）尾肢外肢が短いこと，（3）第1胸肢の長節外縁の剛毛数が少ないこと，（坐
両触角とも鞭数が多いことで区別される。
キーワード：新種，等脚目，分類，コツブムシ科，イソコツブムシ属，紀伊半島。
Anewspecles,G""7"zos蝕唖7℃"zai”ぬ"zsg,wasdescribedonthespeclmens
collectedfromthemouthofTondaRiver，KiiPeninsula・Thisspeciesismostallied
toG'zo""zops“c、"zαα加耐α/0s，buttheformerlsseparatedfromthelatterinthe
followingfeatures:(1)lessnumerousteethonmaxilla，(2)muchshorterexopodof
uropod,(3)lessnumeroussetaeonouterdistalangleonmerusofpereopodl，(4)less
numerousflagellarsegmentsofbothantennae，
Keywords:G加阿"zos"z“γO加α,Sphaeromatidae,Isopoda,NewSpecies,Kii.
Ms，Murata，graduatedstudentofNaraWomen，sUniverslty，happenedtofindfiveindividuals
ofunfamiliarsphaeromatidisopodsduringherecologicalsurvevofanothersphaeromatid，S，加勿り柳α
z(ﾉα”i、ThroughthecourtesvofProfessorWada，NaraWomen，sUniverslty，theywerehandedovertc
me、Atthecloserexaminationofmine，theyprovedtorepresentanewspeclesofthegenus
G"”"zOsp〃zzeﾉり"2α，
G”方”s此α97℃加α#"…〃s9,.sp・
（Japanesename：Tondagawa-Isokotsubumushi，new）
（Fig,A−S）
Mz/”jα/“α加亦だ．：2印。’（1ケholotype，6.lmminbodylength，l3paratype，5．3mminbodylength〉
and3？？（paratypes，3.1〜3.6mminbodylength)，mouthoftheTondaRiver，June，27，1998，coll・
YukoMurata・Thesespecimensaredepositedasfollows：Holotype（TOYA−Crl2595)，and2
paratypes（TOYA-Crl2596〜12597）attheToyamaScienceMuseumand2paratypes（OMNH−Ar4139
〜4140）attheOsakaMuseumofNaturalHistorv．
＊ContributionsfromtheToyamaScienceMuseum,No．204
NoboruNUNOMURA
DCS"i””：Body（Fig．A）rathershort，1．5timesaslongaswide・Colorbrownwithpaler
irregularpatternsonthedorsalsurface・Surfacealmostwithmanymlnutegranules，Cephalonround
Evesmediocreinsize，eachevewith30ommatidia・Pleotelsonwith2pairsofsuturelines，bothare
almostsameinlength；posteriorendstraight、
Antennule（FigB）short；pedunclestoutwith3segments；flagellumwith8〜lOsegmentsandeach
ofthemwithanaesthetasc・Antenna（Fig.C）longerthanantennule，reachingtheposterlorpartof
thethirdpereonalsomite，composedof5peduncularandl4〜l5flagellarsegments、
ClypeusandFrontallaminapentagonaLRightmandible（FigD)．Parsincisivawith3teeth；
laciniamobiliswith4teeth；4plumosesetae；processusmolariswide・Leftmandible、Parsincisiva4-
toothed；laciniamobilischitinizedand4-toothed；plumosesetaebehindthelaciniamobilis；processus
molariswide・PalpsecondsegmentwithlO〜l1setaethirdsegmentwithll〜12setaeMaxillula（Fig
E)．OuterlobewithlOteethatthetip，2mnermostteethshort，4mnerteethdentateandouter4
outerteethsimple；innerlobewith41ongpl'1mosesetaeatthetip・Maxilla（Fi9.F)．Innerlobewith
7〜8plumosesetae；bothlobesofouterlobewith8setae，respectivelv・Maxilliped（FigG)．Endite
with2（sometimesl）couplinghooksandmanvhaironinnermarginand8plumosesetaeondistal
angle、Palpsegmentlwithaseta；segment2withl3〜l4setaeonlnnermarginand2setaeatouter
distalangle；segment3withl21ongerand4〜5shortersetaeoninnermarglnand4setaeatouter
distalangle；segment4with3〜4setaaroundthemargln；terminalsegmentwithl3〜15setaearound
themargin・
Pereopodl（Fig.H）ratherstoutasawhole・Basisrectangularwith2setaeonoutermarginand
asetaatlnnerdistalangle；ischiumwithdensehaironlnnermarglnand；meruswithmanyshort
splnesonlnnermarglnandasetaatouterdistalangle；carpustrlangularwithalongsetaatlnner
margln；propodusrelativelyrobustwith2setaeonmnermargin；dactvlusbifidwith2setaeonone
side，
Pereopod2（Fig.1).Basisrectangularwith3setaeatlnnerdistalangle；ischiumalittleshorter
thanbasiswithmanvshortsetaeoninnermargi、；meruswithmanvhairsoninnermargi､’2setae
atinnerdistalangleand5relativelvshortsetaeatouterdistalangle；carpusrectangularwithmany
hairandalongsetaatinnerdistalangleand4shortsetaeatouterdistalangle；propodusrectangu‐
larwith8setaeonlnnermargin；dactvlusbifid、
Pereopod3（Fig.』)．Basisrectangularwith2setaeonoutermarginandashortsetaatlnner
distalangle；ischiumrectangularwithasetaatlnnerdistalangleandmanvhaironlnnermargln；
meruswithl〜21ongsetaeatmnerdistalangleandmanyhaironlnnermarginand4setaeatouter
distalangle；carpusrectangularwithalongsetaonatlnnerdistalangleand2setaeatouterdistal
angle；propodusrectangularwith2relativelylongsetaeonlnnermargin；dactylusbifid・
Pereopod4，Basisrectangular;ischium2/3aslongasbasis；merushalfthelengthofischiumwith
2setaeatouterdistalangleandsetoseonlnnermargln，carpusalittlelongerthanmeruswitha
longsetaatinnerdistalangleand3setaeonoutermargin；propodusrectangularwith3setaeon
lnnermarginand2setaeatouterdistalangle；dactvlusbifid・
Pereopod5，Basiswithshortsetaonoutermargi、andarelativelvshortsetaatlnnerdistal
angle；ischiumwith2shortsetaeatouterdistalangle；meruswithminutehaironbothmarglnanda
setaatlnner，carpuswith2setaeatouterdistalangleandasetaatinnerdistalangle；propodus
with5setaeininnermarglnandmanvhairvonoutermargin；dactvlusbifidwithaseta、
Pereopod6（FigK)．BasisTectangularwithasetaatlnnerdistalangle；ischiumwithminutehair
onmnermargin；meruswithmanvhaironlnnermargmarelativelylongsetaatlnnerdistalangle
and2setaeatouterdistalangle；carpuswith2setaeatlnnerdistalangleandasetaatouterdistal
angle；propoduswith2setaeoninnermarglnandasetaatouterdistalangle；dactylusbifid．
Gnorimosphaeroma加加Kが
C ： ユ 1 m m
B,H−L,N−S ､ − 1mm
M ‐一 一lmIn
D,G 1，，
E一F 0．5mm
Ｆ・１ｇ・ GγzOγ"JosP""ひ"zai0z“e"s2，，．sp・
訂
ＡⅡ Dorsalview；B・Antennule，C・Antenna；D・RightMandible；E･Maxillula；F、Maxilla；
’
Ｇ一 Maxilliped；H・Pereopodl；I、Pereopod2；J，Pereopod3；K、Pereopod6；L、Pereopod7尋
Ｍ④
● Penes；N・Pleopodl；O・Pleopod2；P・ Pleopod3；Q，Pleopod4：RPleopod5；
Ｓ■
■ Uropod（All；MaleHolotype）．
NoboruNUNOMURA
Pereopod7（FigL）longerthantheprecedingones･Basislongwith8〜lOshortsetaeonlnner
marglnandoutermargln，respectivelyandasetaonatlnnerdistalangle；ischiumabouthalfthe
lengthofbasiswithshortsetaeonbothmarglns，meruswith2setaeonlnnerdistalangleand2setae
atouterdistalangle；carpusaslongasmerus，withlOsetaeondistalmargm；propodusalittle
longerthancarpuswithlO〜12setaeondistalmargin；dactylusbifidwithlor2setaeononeside・
Penes（Fig.M）relativelylong；eachpenis5tlmesaslongaswide・
Pleopodl（Fi9.N)．Basiswith3couplinghooks・Endopodellipticalwithabout35plumosesetae・
Exopodwith55setaearoundthemarg1，．
Pleopod2（Fig.0)．Basiswith3couplinghooks、Endopodsemicircularwithabout55setae
aroundthemargin，Styluslongwithroundedtip，
Pleopod3（Fig.P)．Basisrectangularwith3couplinghooks・Endopodsemicircularwithl5〜l9
plumosesetae，Exopodroundwithabout45setaearoundthemargln、
Pleopod4（Fig.Q)．Basisslenderwith2setae・Endopodwith4shortsetaenearthetiPExopod
with7〜8relativelylongersetaeandl5shortersetaearoundthemargln，
Pleopod5（Fig.R)．Basisshort，Endopodrectangular，Exopodrectangularwith2bosses，
Uropod（Fig.S)．Basistrapezoid；endopodellipsoidwithmanyhairaroundthemargm；exopod55％
ofendopodinlength、
EYy柳OIogy；Thespeciesnameisafterthetypelocality、
HZz6"α／：Thepresentspecimenswerecollectedformtheholeofrocksofestuary、AccordingFukui
andWada（1987)，thebottomwatersalinityfluctuatedfrom5､6to19．3"ooinJuly．
』惣沈”たs：ThepresentnewspeciesisalliedtoG”γ”01s"e”"”αﾉc〃α/0s，reportedfromKorea，but
theformerlsseparatedfromthelatterinthefollowmgfeatures：lessnumerousteethonmaxilla，（2）
muchshorterexopodofuropod，(3)less、umeroussetaeonouterdistalangleonmerusofpereopodL
(4)lessnumerousflagellarsegmentsofbothantennae・
ThepresentnewspeciesisalsoseparatedfromthecommonspeciesinJapanesewater，G"”"2ヶ
s伽“γO脚αmyjHoestlandtinthefollowingfeatures：(1)lessnumeroussetaeonalltheramiofmaxilla．
(2)shorterexopodofuropod，(3)lessnumeroussetaeonbasisandmerusofpereopodl，and(4)more
numerousflagellarsegmentsonbothantennae．
Acknowledgment
lwouldliketoexpressmyslnceregratitudetoProfessorKeijiWadaoftheNaraWomens
UniversitvandMs､YukoMurata，ofthesameunlversltvfortheirkindnessofcollectingsuch
lnterestlngspeclmens・ThistaxonomlcresearchwasfinanciallysupportedpartlybytheSasagawa
ScientificResearcherGrantfromtheJapanScienceSociety．
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