Table Of ContentE、l,t,・a,To(kyo,31(2):439-445,November22,2003
AnIsolatedPopulationofHornoeocarabusmaeander(Coleoptera,
Carabidae)DiscoveredfromaPaisaBogontheDaisetsu-zan
MountainsinHokkaido,NortheastJapan
Yuki IMURA
Shinohara-cho1249-8,Kohoku-ku,Yokohama,222-0026Japan
Abstract AnisolatedpopulationofHolnoeoca1abtls,naeande1'isrecordedfrom
apaisabogontheDaisetsu-zanMountainsincentralHokkaido,NortheastJapan,andis
describedasanewsubspeciesunderthenameno/)ll/(11.
HomoeocarabusmaeanderFISCHERvoNWALDHEIMisasinglecomponentofthe
genusHomoeocarabusREITTERbelongingtothedivisionHemicarabigeniciofthesub-
tribeCarabina(sensuIMURA,2002).Thespeciespreferscoldmarshyenvironment,and
isratherwidelybutsporadicallydistributedmainlyinthesubarcticzoneofnortheast-
ernEurasiaandnorthernNorthAmerica.InJapan,itisendemictoHokkaidoandhas
beenrecordedfrommoorsormarshymeadowsnowdiscontinuouslyextantinthelow
altitudinalareaofthesameisland.Itwasthereforeunexpectedthatapopulationofthe
samespecieswasdiscoveredfromthealpinezoneoftheDaisetsu-zanMountains,the
centralmassifofHokkaido.
Earlyinthesummerof2003,NobukiYAsuDAvisitedanalpinehogtyingatthe
southernsideofMt.Hira-ga-dake(=Hira-ga-take)inthecentralpartoftheDaisetsu-
zanMountainsfor investigatingsoilbeetles.1)Thebogispeculiar inaccompanying
paisa,apeatypermafrostmoun andsuchapaisabogisknownsofaronlyfromthere
inJapan. Together with Au1onocarabus ku1・11ensis dalsetsuzanus KONo and several
othersmallCarabidaesuchasPterostlchussubrugosusSTRANEo,bothofwhicharere-
strictedtothewind-blowncommunityofthealpinezoneoftheDaisetsu-zan,hefound
aseriesofHmaeander inpitfalltrapssetinthebog,andtheyweresubmittedtome
forstudy.Allthespecimenslookedsostrangeinhavingasmallersizeanddarkercol-
oration,andapparentlydistinguishableevenwiththenakedeyesfromtheotherpopu-
lationsof thesamespeciesknown fromHokkaidowhicharerepresentedbysubsp.
paludlsGEHIN.Afteracloseexamination,ithasbecomeapparentthattheDaisetsu-zan
populationbearsseveral other characteristic featuresof itsown,andcanbedistin-
l)ThissurveywasperformedunderthepermissionsoftheMinistryofEnvironment(328thpermission
of theWestHokkaidoRegionalOffice forNatureConservation)andtheHokkaido Board of Education
(3,046thorderoftheCulturalSection).
440 YukilMURA
9uSihablenotonly「fomSubsp.paludisbutfromalltheknownracesofHmaeander l
W加the「etc「edescrbieitasanewsubspeceisinthefololwinglines
Theabb「eViatOinSusedinthetextarethesameasthoseexpalinedInmyprevious
papers.
HOmoeocarabusmaeander,tobukiiIMuRA,subsp
nov
[Japanesename:Takane-sesujiakagane_osamushj]
(Figs.1-3)
Len9th:17・7-20・3mm(includingmandibles).Bodyabovedarkreddishcoppery,
da「kb「ownO「blackWithacopperylustre,sometmi eswjthafajntgreenishtingeon
thelate「alSidesofhead,pronotumandelytra.venterandappendagesbalck
MostCloselyalliedtoSubSp.paludis,butreadilydiscrmj jnatedfromthatraceIn
thefo11oWin9「eSPeCtS:1)Sizealittlesmalleronanaverage;2)darkjndjv1dua1sarere_l
atViely「fequent(ofthetotal23specmi ensexamined,13aredarkreddishcopperyand
Fi9S 1 a 1aea1'de'nObufSubSP nov.(1, holotype;2, ,paratype)fromapaisa
b g ear I k ,
No、vIsolatedRaceofHo111oeo_ra/)t1、.111aeande1 441
10aredarkbrownorblackwithacopperylustre),whereastheyaremuchlessfrequent
insubsp.paludis);.3)dorsalsurfaceofmandiblesmoresparselyandweaklypunctured;
4)antennaeshorter,barely reachingbasal fifthofelytrainmale,whiletheyusually
reachbasalquarterinsubsp.paludis;5)marginalsetaeofpronotumcompletelylostin
all thespecimensexamined, whiletwopairsofsetae(onemedianandonebasal)are
insertedinsubsp.paludis;6)basal foveaeofpronotumalittleshallower;7)humeral
serrationofelytracompletely lost inall thespecimensexamine whereas it is con-
stantlyrecognizedinsubsp.paludis.
MalegenitalorganasshowninFig 3.Aedeagusslender,weaklybent ventrad
near thebase,nearlystraightandparallel-sidedinmedianportionandgraduallybent
ventradtowardstheapex; apical lobelongandnarrow,not faintlyconvergentnearthe
baseas insubsp.paludisbut almostparallel-sided, itsdorsalmargingently arcuate
throughoutandobtuselyroundedatthetipinlateralview;basaledgeofmembraneous
preostiumnarrowlyelongate towardsbaseofaedeagusto formalongitudinal furrow
ondorsalwalletaedeagus; 0Lmediumtolarge-sized, rather wideat thebaseand
bilobedatthetip;1igulumindicatedbyawelldevelopedpatchofpigmentedgranules;
neitherBLnorMLdeveloped,thoughdorsalwalletendopha11usapparently inflated
near thebase;PREmoderatelyor ratherprominently inflate not bilobedand almost
Fig.3. Malegenitalorganofrio,noeoca,-abi1.l111aea,Ido・l11obuki1subspnov. - a,Acdeaguswithfully
evertedendopha11usinrightlateralview;b,dittoinposterior(dorsal)view;c,dittoin frontal(ventral)
view;d,apicalpartofaedcagusinrightlateralview;e,dittoindorsalview. Arrow indicatesa me m-
braneousfurrowonthedorsalwalloftheacdeagus.Scale:lmmfolra-c;0.5mmford&e.
442 Yuki IMURA
symmetricalinshape;PPlargeandbilobed,witheachlobealmostsymmetricallypro-
trudedandroundedat thetip;PARabsent;ALnotsolargebut ratherstronglypro-
truded laterad; PL not inflated; AGGunremarkable,neitherstronglysclerotizednor
pigmented.
Typeseries. Holotype: ,paisabog,atanaltitudeof1,720m,500-700mdis-
tanttothesouthfromthepeakofMt.Hira-ga-dake,inthecentralpartoftheDaisetsu-
zanMountainsinCentralHokkaido,NortheastJapan,9-VII-2003,N.YAsUDA leg.,
preservedinthecollectionoftheDepartmentofZoology,NationalScienceMuseum
(Nat.Hist),Tokyo.Paratypes:5 17 ,samecollectingdataasfor theholotype,
,
inthecollectionsofN.YAsUDAandY. lMURA.
Discussion
Thehabitatofthepresentnewsubspecies,analpinehogtyingatthesouthernside
ofMt. Hira-ga-dake, ispeculiar inaccompanyingpaisa.Paisaisoneof thecircum-
glacial landformsdistributedinthepermafrostzone, indicatingapeaty permafrost
moundwith the height about 0.5 to temand thediameter exceeding about 2m
(WASHBURN,1983).ThepaisabognearHira-ga-dakewasdiscoveredanddescribedfor
thefirsttimebyTAKAHAsHlandSONE(1988),andsuchalandformhasnotbeen found
sofaranywhereelseinJapan.AccordingtoTAKAHAsH1andSONE(1988),itislocated
onabroadpassontheandesiticlavaplateauatanaltitudeof1,720m,measured650m
fromeasttowestand350mfromnorthtosouth,attainingtoabout103hainarea.Av-
erageannual temperatureatthesamesiteisestimatedatabout -2°C(SONE,2002).
The vegetation in thebogismainly composedofsphagnumand sedge.Such
plantsas rosef'a oftM ofza, n romeda o/jfofzaand accfmzmoxycoccumarealso
as do inant,partlyassociatedwithMenyant fl'lfofzat an rfop ortm vagznattM7.On
thesurfaceofthepaisaisdrierthanthesurroundingbog,andiscov-
the other han
s , ered with fapensfa /appomcav. obovafa, ryantﾝzf git7e/lmz Get// enfapefa/tm
andseveral kindsoflichens,withapartial invasionofyoungPlnuspum11a fromthe
surroundingarea(TAKAHAsHI&SONE,1988).
Fromthebotanicalpointofview,thispaisabogispeculiar inharboringtwoen-
demicspecies;oneisacircumpolarsedge,Care)crotundataWAHLENBERG(SATo &
TAKAHAsH1,1994)andtheotherisanarcticmoss,Loeskypnumbadium(HARTM)PAUL
(KANDA&SATo,1994).Boththespeciesaredistributedratherwidelyinthecircumbo-
rea1tosubarcticzonesoftheNorthernHemisphere,buthavebeen recordedinJapan
only fromthebognearHira-ga-dake,andareconsideredtobearelictofthepastcold
time.
Inviewofthecarabido1ogy,twospeciesofthesubtribeCarabinawereobtained
fromthesamebogbypitfall traps.0neisAu1onocarabus(s.str)kurilensisLApoUGE
(sensu IMURA,2002,asregardsthegenericclassification) andtheother is Homoeo-
car,abus 'naeander FISCHER voN WALDHEIM. The former is represented by subsp
daisetsuzanus KONo, whichisoneofthedominantcarabidsin thewind-blowncom-
New IsolatedRaceof rio,11oeocalaltls1111eande, 443
munityofthealpinezoneoftheDaisetsu-zanandhashithertobeenrecordedfromthe
areabetweenMt.Kuro-dakeandMt.Tomuraushi-yama(YAsUDA,2001).Accordingto
YAsUDA(pers.comm), thisspecieswasdominantalsointhebog,thoughpreferring
drierenvironment.Incontrast,thelatterwascollected frommarshyplacesaroundthe
small pondsoften associated with the palsas, andseemed to beconfined tosuch a
strictlynarrowhabitat.TheDaisetsu-zanpopulationofHmaeande1-ispeculiarinsev-
eral respectsand doubtlessbelongs toanewsubspeciesasdescribed in thepresent
paper
InHomoeoca,abusmaeandel-nobuk1i nov.,allthemarginalsetaeofthepronotum
arecompletelylostandthehumeralserrationsoftheelytraarenotrecognizable.Inad-
dition,thebasaledgeofthemembraneouspreostiumofthemalegenitaliaisnarrowly
elongatetowardsthebaseoftheaedeagustoformalongitudinal furrowonitsdorsal
wall.Ailthesecharacterstatesarequiteexceptional forthespecies,andareconsidered
tobeauniqueautapomorphyoftheDaisetsu-zanrace.Thisseemstorepresenteithera
longhistoryafter isolationorarapidmorphological changecausedby itsdistinctive
habitat.Inmanyrespects,theymusthavebeenisolatedafterthepastcoldtimewithout
minglingwiththeotherpopulationofthesamespecies,andtheoriginandperiodof
their immigration intoHokkaidomight havebeen different from those ofsubsp.
paludisnowdistributedmuchmorewidelyinthelowaltitudemoorsofthesameis-
land.
Fig. 4. HabitatofH()1noeoca,・abllsmaeande,・11obukiisubspnov.(paisabog,1,720minalt.,southofMt.
Hira-ga-dakeontheDaisetsu-zanMountains;arrowindicatesapaisa;Mt.Hakuun-dakecanbeseenin
thedistance)(photographbyN.YAsuD^inJuly2003).
444 Y1lilki IMURA
Sincethehabitatofthenewraceislocatedinthespecialprotectionzoneofana-
tionalnatureconservationarea,itwillbewellprotectedagainstdisturbancecausedby
collectors. Asmentionedintheprecedinglines,however, thehabitat isnarrowlyre-
strictedtoasmallalpinebogwhichiscompletelyisolatedfromalltheotherknownlo-
calitiesofthesamespecies.Tomakemattersworse, totalareaofthepalsashasbeen
gradually reducing for thepastseveraldecades.Forexample, theywerereducedto
abouttwo-thirds(rateofreductionwasestimatedat36%)accordingtotheobservation
madeby air photographs taken from 1955 to t982 (TAKAHAsHI & SONE, 1988).
ThoughH maeande1isnotnecessarilydependinguponthepaisaitself,itseemscer-
tainthattheclimaticchangesresultingfromthewarmingoftheglobemayhaveanad-
verseeffectonthebogan initsturn,influencethemeager faunaandfloradepending
onthisdistinctiveenvironment.Fromsuchapointofview,thenewracemaybeworth
regardingasathreatenedlocalpopulation.
Acknowledgements
IwishtoexpressmydeepindebtednessfirstofalltoMr.NobukiYAsuDA,chief
oftheDaisetsuzanNationalParkSounkyoVisitorCenter,withoutwhoseenthusiastic
searches,thisremarkablenewpopulationcouldnothavebeenbroughttolight.Hearty
thanksshouldalsobeexpressedtoProfessorNobuyukiTAKAHAsHIofHokkai-Gakuen
University,Sapporo,andDr.ToshioSONEoftheInstituteofLowTemperatureScience,
HokkaidoUniversity, for kindly providingmenecessary literatureof geology and
botany, aboveall thoseconcerning thepaisaofDaisetsu-zan, and toMessrs. Mi-
tsumasaKAwATAofSapporoandKiyoyukiMlzusAwAofYokosukafortheirkindness
inallowingmetoexaminethespecimensofH maeanderpreservedintheircollec-
tions forcomparativestudy.Cordial thanksareduetoDr.Shun-IchiUENooftheNa-
tionalScienceMuseum,Tokyo, forcriticallyreadingthemanuscriptofthispaper.
要 約
并村有希:北海道大雪山のパルサ湿原から発見されたセスジアカガネオサムシの孤立集
団. _ セスジアカガネオサムシは, 北東ユーラシアから北米にかけての亜寒帯地域を中心
に分布する好湿性の極で, わが国においては北lリf道のみから知られており, これまでに確認さ
れた生息地はいずれも低湿地帯ないしそれに準じた環境に限られていた. しかしながら今夏,
大雪山層要峡l ビジターセンターの保田信紀氏により, 大雪山系中央部の平ヶ岳南方較部 (標高
l,720m) にある小湿原から, 同極の特異な小集団が発見された. 同湿原は, 永久凍土地帯に分
布する周氷河地形のひとつであるパルサ (泥炭質の永久凍土丘) を伴つているとぃう点におぃ
てきゎて特異であり, わが国唯一のパルサ湿原として知られている. 同地のセスジアカガネォ
サムシは, 氷期以降の比較的長い年月を, 他集団との造伝的交流を絶たれた状態で過ごしてき
たことは疑いなく, その進入経路や年代も, 道内各地の低湿地に分布している集団とは異なる
ものかもしれない. 形態学的にみても, 前月向背板剛毛や肩部鋼歯状突起を欠く点, さらに.、茎
NewIsolatedRaceofHo111oeoca1abus1naeant/e' 445
背面に長く亀裂状に伸張する膜状の清.がみられる点など, いくつかの特徴的な形質をそなえて
いることがあきらかになったので, 発見者の保田氏にちなみ, この集団にタカネセスジアカガ
ネオサムシsubspnobukiiという新亜種名を与えて記載した.本新亜種の生息地は, 大雪山国立
公園の特別保護区内にあるため, 採集圧による個体数の減少が問題となることはないだろう.
しかしながら, その生息地はわずか1.3ヘクタールの面積をもつに過ぎない孤立した湿原であ
り, また, 同地のパルサの総面積は年ねん減少しているという. 地球温暖化に伴うこうした環
境条件の変化が, 同地の希少な動植物相にも今後, 少なからぬ影響を与えてゆくであろうこと
は明白で, こうした点を考慮に入れると, 本新 種は, 絶減の恐れのある地域個体群に匹敵す
る扱いがなされてもよいであろう.
References
FISCHERvoNWALDHEIM,G.,1820-'22. EntomographiaimperiiRussici,1. viii十208pp.Mosquae.
(JEHIN,J.B.,1885. CataloguesynonymiqueetsystematiquedesColeopteresdelatribudosCarabides,
avecdosplanchesdessineesparCh.HAuRY. xxxviii十104pp.,10pls.Remiremont&Prague.
IMURA,Y.,2002. ClassificationofthesubtribeCarabina(Coleoptera,Carabidae)basedonmolecularphy-
logeny. Elyt;a,「okyo,30:1-28.
KANDA,H., &K.SATo,1994. Anarcticmoss,Loeskypnumbadiu1n(HARTM)PAUL(Amblystegiaceae),
newtoJapan. 1 ｽ la, lgas1/1-1/1・,os1/1,Ila,11:429 33.
KONo,H.,1936. DieKafer-FaunavomDaisetsuGebirge. Biogeog,aphica, nokyo,1:75-104.(InJapa-
nese,withGermantitle)
LApoUGE,G.V:DE,1913. Carabesnouveaueumatconnus. Misc ent.,21(1):1-241.
REITTER,E., l896. Bestimmungs-Tabe1ledereuropaischenColeopteron,Carabidae,1,Carabini,glcich-
zeitigmiteinersystematischenDarste11ungsammtlicherSubgeneraderGattungCa,abusL. Vet'1/.
natulf Ve,.B,unn,34:36-198.
SAT0, K., & N. TAKAHASHl, 1994. Ca''e、.' rotundata WAHLENB. (Cyperaceae) from Mts. Daisetsu in
Hokkaido,newtoJapan. J.Jpn.Bet.,69:235-238.(InJapanese,withEnglishtitle)
SONE,T.,2002. InternalstructureofapaisainthebogtothesouthofMt.Hiragatake,theDaisetsuMoun-
tains,Hokkaido,Japan. JGeog,:,111:546-554.
TAKAHAsH1, N., & T. SONE, l988. Palsas in the Daisetsuzan Mountains, central Hokkaido,Japan.
Geog,.Rev.Japa,1,61(Ser.A)-9:665-684.(InJapanese,withEnglishtitleandsummary)
WASHBURN,A.L.,1983. Whatispaisa?/,1POSER,H.(ed),MesoformcndosheutigenPeriglazialraumes
(GeomorphologischesSymposium,KehrbeiGottingen,l982). P・,co., (,ottt,1ge,1Akad.Wiss.,34-47.
YAsUDA,N.,2001. Groundbeetlescommunitiesof thehighaltitudezoneinMts.Daisetsu,Hokkaido.
Bull.Soml kyoVisito・,Cento,・,(21):1-26.
