Korea Strait delimiting distribution of distinct karyomorphs of Crocothemis servilia (Drury) (Anisoptera: Libellulidae)

6 Pages·2001·1.4 MB·English

by  Higashi, K

Odonatologica30(3): 265-270 September1, 2001
KoreaStrait delimitingdistributionof distinct
karyomorphsofCrocothemisservilia (Drury)
(Anisoptera: Libellulidae)
K.Higash¹iC.E.Lee H.Kayano³ andA.Kayano³
²,
1 DepartmentofAppliedBiologicalSciences,Faculty ofAgriculture,SagaUniversity,
Honjyo-machi1,Saga840-8502,Japan
e-mail: [email protected]
2 EntomologicalInstitute ofKorean Peninsula,Hyomok-2Dong615-2, Dong-ku,
Taegu701-032,RepublicofKorea
3Kujyu-HighlandInstituteofBiology,Kuju4026,Kuju-machi,Naoiri-gun,
Oita878-0201,Japan
ReceivedAugust22, 2000/Revised andAccepted January18,2001
Inordertodefinetheeasternlimit ofthedistribution ofC.s.servilia (2nd=25,XO)and
thewesternlimitofC. s. mariannae(2nd=24,neo-XY),thekaryotypeswerestudiedin
specimensfromChejuisland andthemainland oftheRepublicofKorea,andfromtheislands
ofNorth Kyushu,Japan.Thedividinglinebetweenthe2sspp. appearsin theKoreaStrait,
betweentheKoreanmainlandandTsushimaisland.Themechanismofmaintainingadistinct
karyomorphineachareaofdistributionisdiscussedin details.
INTRODUCTION
Crocothemisserviliaoccurs fromtheMiddleEast, through southernAsia,China,
Australia,theSundaicArchipelago toJapanandincludestwodistinctkaryomorphs:
one,2nS =25withXOsex determiningsystem, andthe other,2nd =24withneo-
-XY system. The former karyomorph was found in specimens from China,
continentalAsia,thePhilippines andTaiwan,andthelatterwasfoundinspecimens
collectedfromKyotoandOsakain Japan(KIAUTA, 1983).Onthisbasis, KIAUTA
(1983) establishedanewsubspecies, C.serviliamariannae,toseparatetheJapanese
populations fromthoseinotherregions.
In a previous paper (HIGASHI & KAYANO, 1993), we reported that the
distributionofthe two karyomorphs ofC. servilia split betweenthe islands of
YakushimaandAmamioshima.Allthespecimens fromAmamioshimaislandand
localitiesSouth ofit had 2n<3 =25 with XO, as found by KIAUTA (1983) in
266 K.Higashi,C.E.Lee, H.Kayano&A.Kayano
specimens fromTaiwan.AllthosefromYakushimaisland andlocalitiesNorthof it
had2nt? =24withneo-XY,as foundby KIAUTA(1983)inspecimens fromKyoto
andOsaka, Japan.
Taking thestudiesofKIAUTA (1983) andHIGASHI & KAYANO (1993)into
account, INOUE & TANI (1999) and SUGIMURA et al. (1999) treated the
populations ofC. serviliadistributedover the area fromAmamioshimaisland to
southernlocalitiesas C. s. servilia and the onesfromYakushimaisland andthe
localities Northofit as C. s.mariannae.
Inordertofindtheeastern limitofthedistributionofC.s.serviliaandthewestern
limitofC. s. mariannae,we collectedspecimens from localitiesin Cheju island
andthemainlandoftheRepublic ofKorea,andfromislandsofNorthKyushu, Japan.
The dividing linebetweenthetwo subspecies was foundtolieinthe KoreaStrait
betweentheKoreanmainlandandTsushimaisland.Thepresentpaperalsoreports
chromosomesof specimens collectedfromThailand.
MATERIALANDMETHODS
SpecimensofCrocothemisserviliausedforchromosome preparationwerecollected fromthe following
localities:
(1) REPUBLIC OFKOREA; lij,Kangnung,Kangwondo,13-VII-1994 (specimenNo.Ka-I); —3c?,
Yongdok,Kyongsangpukdo, 12-VII-1994(NosYo-1,2&3);— 4c?,Kyongsan,Kyongsangpukdo, 14-
-VU-1994(NosKy-1,2, 3 &4); — 3c?,Sogwipo, Chejudo(Cheju-island),5-VII1-I996(NosCh-I,
So-1 &2).
(2) JAPAN;13c?,Kamiagatachou,Tsushima-island,Nagasakipref. I3-VII-1992(Nos Th-1,2& 3,Sh-1,2,
3,4,5,6,7, 8,9& 10); —3c?,Mitsushimachou inTsushimaisland,Nagasakipref. 14-VII-1992(Nos
Mt-1,2&3);—5c?,Gounourachou&Ishidachou,Ikiisland,Nagasakipref., 15-VH-I992(NosDd-1,2,
3,4&5); —4<?,Fukue,FukuejimaislandinGotorettoArchipelago,Nagasakipref.,31-VH-1997(Nos
Fu-1,2,3,4&5).
(3) THAILAND:2c?,ChiangMai(ChiangMaiUniv.), l-X-!999(NosChn-l&2),8c?,BanBoLuang,30-
-IX&1-X-I999(NosBl-1,2,3,4,5,6,7&8).
Themaleswerefixedwithaceticalcohol(1:3)immediatelyafterorwithin onedayofcapture.Thespecimens
weretransferredto70%ethanolaftertwodaysoffixationorkeptinthefixingsolutionandstoredinarefrigerator.
Toobservespermatogonialandprimaryspermatocytechromosomes,testesweredissectedoutin70%ethanol
orinthefixingsolution andwerestained for2to3hourswith alcoholic hydrochloricacid-carmine(SNOW,
1953).Each testiswascutintopieces andeachpiecewasmadeintoatemporarysquashpreparationusing45%
acetic acid.Afterdissection,thespecimenswerekeptin70%ethanoland storedin arefrigerator.
RESULTSAND DISCUSSION
Primary spermatocyte complements in specimens from the islands in North
Kyushu, Japan(Tsushima, Iki,Fukuejima), showedtwelvebivalents(n = 12)(Fig.l
A-C).Thiskaryomorph, withoutan“in”bivalent(see,below),hasaheteromorphic
bivalentformedbyneo-Xandneo-Ychromosomes(neo-XY),similartothatshown
by KIAUTA (1983)in specimens fromKyoto andOsaka.
Thekaryomorph isidentictothatoccurringinallthespecimens fromYakushima
Distribution ofkaryomorphsin Crocothemis servilia-complex 267
islandandfromlocalities
Northofit(HIGASHI &
KAYANO, 1993). The
originofthe neo-XY is
explicable in terms ofa
change from XO. A
translocationbetweenthe
X and an “m” chromo-
some, followedbylossof
apart oftheproduct, has
given a neo-X chromo-
some. Theunpaired “m”
hasremainedas aneo-Y
(KIAUTA 1983;HIGA-
SHI&KAYANO, 1993).
On the other hand,
specimens from the
Republic ofKorea(Cheju
island,Kyongsan, Yondo-
ku and Kangnung), and
thosefromThailand(Ban
Bo Luang), showed in
primary spermatocytes
twelve bivalents and a
univalent(n= 13) (Fig.l Fig. 1.Primaryspermatocytechromosomesatdiakinesisormetaphaseof
C.serviliafromdifferentlocalities:(A-C)n= 12(<C.s.mariarmae)from
D-F). The univalentre- Ddisland (A),Tsushimaisland (B)andFukuejimaislandin Gotoretto
presents the X and the Archipelago(C),Japan;—(D-F)n=13(C.s.servilia)fromChejudoisland
smallestbivalent,the“m” (D)andYongdok(E), bothKorea, andfromBanBoLuang,Thailand(F).
chromosome.Thesexde-
termining system is XO. This karyomorph is also foundin all specimens from
AmamioshimaislandandfromlocalitiesSouthofit(HIGASHI&KAYANO, 1993).
Itis identictothatreportedby KIAUTA (1983)inspecimens fromcontinentalAsia,
China,thePhilippines andTaiwan.
From the present and earlier investigations (KIAUTA, 1983; HIGASHI &
KAYANO, 1993),itisunequivocal thatC.serviliamariannaeisendemictoJapan;
in the South its distributionrangereaches Yakushimaisland, wherethe western
borderisrepresented byTsushimaislandandtheGotorettoArchipelago. (C.s.servilia
occurs SouthofAmamioshimaisland.Theeastern limitofits distributionis Cheju
islandandmainlandoftheRepublic ofKorea(Fig. 2 A,B).
Itwouldbeinteresting toascertainthe subspecific identity ofthepopulations in
theTokararettoArchipelago,connecting theAmamioshimaandYakushimaislands.
Oneof thepresent authors(K.H.), triedto collectC. servilia ontheislandsofthe
268 K.Higashi,C.E.Lee, H.Kayano&A.Kayano
Fig. 2.Distribution ofCrocothemis serviliakaryomorphs:(A)Korea and theislandsNorthofKyushu, Japan;
— (B)Kyushu andtheJapanesesouthwesternislands. — [Dots indicate collectingsites]
TokararettoArchipelago, i.e.onKuchinoshimaand Takarajima, inmidJuly 1998,
and onKuchinoshima, Nakanoshima, Akusekijima and Takarajima, in mid July
1999.Unfortunately, thespecies was not foundon any ofthese.
ItisconceivablethatC. s. serviliaindividualscouldmigrateintotheareaofC.s.
mariannae,and vice versa. Themechanismtomaintaina distinctkaryomorph in
eachareaofdistributionis discussedbelow.
Wemustfirst considerthepossibilityofhybridizationbetweenthetwo subspecies.
Here,thekaryomorph ofC. s.mariannaeisdenotedby 2n? =24(22+neo-X+neo-
-X) and 2n<? = 24 (22+neo-X+neo-Y) and that of C. s. servilia. 2nV = 26
(22+m+m+X+X) and2nd=25(22+w+m+X). Inthecaseofhybridizationbetween
C. s. servilia (9)and C. s. mariannae(<?),Fl’s are2n? = 25(22+w+X+neo-X)
and2nd =25(22+/n+neo-Y+X)whichissubstantially22+m+m+Xandequivalent
to themaleofC. s.servilia(Tab. I, A).
Hybridization betweenC. s. mariannae(?) andC. s. servilia(c?) willproduce
Fl’s consisting of2n9 =25(22+w+X+neo-X)and2nc? =24(22+w+neo-X)which
is substantially 22+neo-Y+neo-Xandequivalent to the maleof C. s. mariannae
DistributionofkaryomorphsinCrocothemis servi/ia-complex 269
(Tab.I, B).
TheFl females,2n9 =25(22+m+X+neo-X) are partially sterile,because dueto
randomsegregationofthemchromosomein meiosis, onehalfoftheeggs arenot
functional.TheFl femaleswillgive fourkinds ofgametes; (1) n= 12(11+neo-X),
(2) n = 13(11+m+X), (3) n = 13(11+m+neo-X) (excess of “m”),and (4) n = 12
(11+X)(shortnessof“m”).Among these,types (1)and(2)aregenetically balanced
(functional in fertilization),but types(3) and(4) are genetically unbalanced(not
functional).
Secondweconsiderhowforeign chromosomalelementsbehaveafterthehybrid
femalesrepeatedlyback-cross to member(s)ofthesurrounding “native”population.
As mentionedabove, the Fl femalesarepartially sterile, irrespective ofdirection
ofcrosses betweenthetwo subspecies. Inthecaseof thesurrounding population
being C. s. mariannae,females intheoffspring areoftwo kinds, onehalfis C. s.
mariannaeand another half, hybrid type (Tab. II). Inthemales ofback-crossed
offspring, one halfis C. s. mariannaeand anotherhalf, C. s. servilia. In each
generation ofthe offspring afterimmigration, thetheoreticalrate of C. s. servilia
males and hybrid typefemalesdecreasetohalfoftheprevious generation.
IncasesofthehybridsbeingsurroundedbymembersofC. s.servilia(immigration
ofC. s.mariannaeintoapopulationofC.s. servila),back-crosses willgiveoffspring
in whichonehalfofthefemalesis hybridtypeandtheotherhalfis C. s. servilia
(Tab. II). Inmalesoftheback-crossedoffspring, onehalfis C. s. servilia andthe
otherisC. s.mariannae.Theoretically,therateofC.s. mariannaemalesandhybrid
typefemalesdecrease tohalfofthe previous generation.
Therefore, as long as the immigrants arerare in thepopulation, itis likely that
the foreign karyomorph introducedby the immigrants will disappear from the
population in a few generations. In fact, exchange ofindividualsbetween the
populations ofdifferentkaryomorphs is veryrestrictedbecausethetwo karyomorphs
are distributed in differentareas, separated by the sea over a long distance.
Table!
Presumptivechromosomeconstitutions ofhybrids(Ft)resultingfrom crossesbetween twosubspecies ofC.
servilia;inFl males“m+neo-Y”isequivalentto“m+m”andunpaired“m”issubstantially“neo-Y”
((AA)) CC..ss..mmaarriiaanrmnaaee((<<5?))x*(CC..ss..sseerrvviilliiaa((2$))
SSppeerrmm EEggggnn==1133((1111++mm++XX))
nn==1122((1111++nneeoo--XX)) ((22nnS9==2255))2222++mm++XX++nneeoo--XX hhyybbrriiddttyyppee
nn== 1122((1Il1++nneeoo--YY)) ((22nn<c?J==2255)) 2222++mm++nneeoo--YY++XXsseerrvviilliiaa ttyyppee
((BB))CC..ss..sseerrvviilliiaa((dcJ))xxCC.is.mmaarriiaarnmnaaee((2$))
SSppeerrmm EEggggnn==1122((1111++nneeoo--XX))
nn==1133((1111++mm++XX)) ((22nn52 ==2255))2222++mm++XX++nneeoo--XX hhyybbrriiddttyyppee
nn==1122((1111++mm)) ((22nnJd==2244))2222++mm++nneeoo--XXmmaarriiaarnmnaaeettyyppee
270 K.Higashi,C.E.Lee, H.Kayano&A.Kayano
TableII
Presumptivechromosomeconstitutionsexpectedinoffspringresultingfromback-crosses betweenfemalesof
FIhybridfromC. s.servilia|(<J)XC.s.mariannae($)orvice versaand“native”males;(a-1,a-2): spermfrom
C.s.mariannae; (b-1,b-2):spermfromC.s.servilia:inmales“m+neo-Y”isequivalentto“m+m”andunpaired
“m” issubstantially“neo-Y”
SSppeerrmm EEggggnn==1122((111l++nneeoo--XX)) EEggggnn== 1133((1111++mm++XX))
((aa--11))nn== 1122((11ll++nneeoo--XX)) ((22nn9$==2244)) ((22nn95==2255))
2222++nneeoo--XX++nneeoo--XX 2222++mm++XX++nneeoo--XX
mmaarriiaannnnaaeettyyppee hhyybbrriiddttyyppee
((aa--22))nn== 1122((111l++nneeoo--YY)) ((22nndd==2244)) ((22nndd==2255))
2222++nneeoo--XX++nneeoo--YY 2222++mm++nneeoo--YY++XX
mmaarriiaannnnaaeettyyppee sseerrvviilliiaattyyppee
((bb--11))nn== 1133((1111++mm++XX)) ((22nn99==2255)) ((22nn59==2266))
2222++mm++XX++nneeoo--XX 2222++mm++mm++XX++XX
hhyybbrriiddttyyppee sseerrvviilliiaattyyppee
((bb--22))nn== 1122((1ll1++mm)) ((22nndd==2244)) ((22nndd==2255))
2222++mm++nneeoo--XX 2222++mm++mm++XX
mmaarriiaannnnaaeettyyppee sseerrvviilliiaattyyppee
Geographic isolation is a primary cause of maintaining the distinctness of
karyomorphs ofthetwo subspecies.
ACKNOWLEDGEMENTS
WethankDrB.KIAUTA forhis valuablecommentsandEnglishcorrectionwhichimprovedthemanuscript
WearealsoindebtedtoDrS. 1T0,DrM.WATANABEand DrT.UEDAfortheirsupportofthisresearch.
ThisworkwassupportedbyaGrant-in-Aid forScientificStudyfromtheMinistryofEducation,Science and
Culture(Nos04045041 and61540475),and wasalso partly supportedbyNissan ScienceFoundation.
REFERENCES
HIGASHI,K.&H.KAYANO, 1993. The distribution ofdistinctkaryomorphsofCrocothemis servilia
Drury (Anisoptera,Libellulidae)in Kyushuandthe south-western islands ofJapan.Jap.J.Ent.
61: 1-10.
INOUE,K.&K.TANI, 1999.Allaboutdragonflies.Tombow,Osaka.
KIAUTA, B„ 1983. The status ofthe JapaneseCrocothemis servilia(Drury) asrevealedbykaryotypic
morphology(Anisoptera:Libellulidae).Odonatohgica12: 381-388.
SNOW,R„1953.Alcoholic hydrochloricacid-carmine asastainforchromosomesin squashpreparations.
StainTechnol. 38: 9-13.
SUGIMURA,M,S. 1SHIDA,K.KOJIMA, K.ISHIDA&T. AOKI, 1999,DragonfliesoftheJapanese
archipelagoin color.Hokkaido Univ.Press.