TurkJZool 28(2004)129-134 ©TÜB‹TAK ComparisonofFemaleAntennulesinSomeGeneraofCyclopidae (Copepoda,Cyclopoida):TheirSignificanceforPhylogeny* SüphanKARAYTU⁄,SerdarSAK,AlpALPER Bal›kesirUniversity,FacultyofArtsandScience,DepartmentofBiology,10100Bal›kesir-TURKEY Received:21.11.2002 Abstract: ThehomologyoftheantennularysegmentsofspeciesbelongingtosomegeneraofCyclopidaeisdeterminedbycomparing thecommonsetationpatternsonfemaleantennules.Comparisonofthesetationpatternhasconfirmedthattherearealways44 setaeand3aesthetascsonthefemaleantennulesofallthegeneraexamined.Thisstudyshowsthatthestrictapplicationofhomology isessentialinordertoresolvethephylogeneticrelationshipsbetweenthegeneraofCyclopidae.AlthoughbothEctocyclopsphaleratus andParacyclopscanadensis have11-segmentedantennules,theanalysisofsegmentalhomologieshasshownthatthe11-segmented conditionhasoccurredduetoconvergentevolutioninthesetwospeciesbelongingtodifferentgenera.Inaddition,severalsegmental fusionsofthefemaleantennuleshavebeenidentifiedasapomorphicstatesandcanbeusedinphylogeneticstudies. KeyWords: Copepoda,femaleantennule,homology,Cyclopidae Cyclopidae(Copepoda:Cyclopoida)Familyas›n›nBaz›CinslerineAitTürlerAras›ndaBirinci AntenKarfl›laflt›rmas›veFilogenidekiÖnemi Özet: Cyclopidae(Copepoda,Cyclopoida)familyas›n›nbaz›cinslerineaittemsilitürlerindiflilerininbirinciantenleriaras›ndakisegment homolojileriantenlerüzerindekiortaksetaldüzenkarfl›laflt›r›larakbelirlenmifltir.Setaldüzenlerinkarfl›laflt›r›lmas›,incele nentüm cinslerineaittürlerdesetasay›s›n›ndaima44veaesthetascsay›s›n›nisedaima3oldu¤unuortayaç›kartm›flt›r.Cinsleraras› ndaki filogenetikiliflkilerina盤aç›kart›labilmesiiçindetayl›homolojianalizininkesinliklegereklioldu¤uortayakonulmufltur. Ectocyclops phaleratusve Paracyclopscanadensis türlerininherikisindedeantenler11segmentliolmas›nara¤men,11segmentlilikdurumufarkl› cinslereaitbutürlerdekonvergentevrimsonucuortayaç›km›flt›r.Bunlaraekolarak,difliantensegmentlerindemeydanagelenp ek çoksegmentalkaynaflma,filogenetikanalizdekullan›labilecekbirçokapomorfiortayaç›kartm›flt›r. AnahtarSözcükler: Copepoda,diflibirincianteni,homoloji,Cyclopidae Introduction devotesufficientattentiontohomologyliesattheorigin ThefamilyCyclopidaeDana,1853,belongingtothe ofmanyofthenewphylogeneticschemesthatappearand orderCyclopoida,currentlycontainsnearly50genera thendisappearagainwithgreatrapidity.Phylogenetic (DussartandDefaye,1985;Reid,1988,1993).Thereis analysiscanbestbeimprovedbymakingpositive noexistingmodernsystematicstudyoftheentirefamily statementsonthehomologyofallthecharactersusedin Cyclopidae,norofthesubfamiliesEucyclopinaeand theanalysis(HuysandBoxshall,1991;Boxshalland Cyclopinae.MostofthegeneraintheCyclopidaearein Huys,1992;KaraytugandBoxshall,1996,1998a, urgentneedofrevision(Karaytug,1999). 1999). Thestrictapplicationofhomologyininferringthe Theantennulesofcopepodsareuniramousand copepodphylogenybyHuysandBoxshall(1991)has compriseupto27expressedsegments(Huysand beenarevolutioninsystematicstudiesoncopepods. Boxshall,1991).Thefemaleantennulesofthegeneraof BoxshallandHuys(1992)stronglystressedthatthe Cyclopidaearebasicallycylindricalwithnomorethan21 identificationofhomologouscharactersandcharacter expressedsegments.The21-segmentedantennulehas statesisapriorityforphylogeneticanalysis,andthemost onlybeenrecordedinspeciesof EurytePhilippi,1843. difficulttaskinanyphylogeneticstudyiscorrectly Thefirstattempttoidentifythepatternofsetaland identifyinghomologoussharedderivedcharacterstates segmentalhomologies(withreferencetothehypothetical (synapomorphies).Theyconcludedthatafailureto 28-segmentedantennuleoftheancestralcopepod *ThisworkwaspresentedattheXVINationalBiologyCongressheldin‹nönüUniversity,Malatyaon4-7September2002. 129 ComparisonofFemaleAntennulesinSomeGeneraofCyclopidae(Copepoda,Cyclopoida):TheirSignificanceforPhylogeny proposedbyHuys&Boxshallin1991)ofthefemale Macrocyclopsfuscus (Jurine,1820):(Turkey, antennuleswithinthefamilyCyclopidaewasmade ‹kizcetepelerdamlake,Balıkesir,25.05.2001,coll.S. betweenthespeciesof Paracyclops Claus,1893.This Karaytug). studyshowedthatsuchexaminationofthefemale Acanthocyclopsrobustus (Sars,1863):(Turkey,a antennulecouldprovidesignificantinformationforthe creekinOrmanlıvillage,Istanbul,30.04.2001,coll.S. ratherconfusedsystematicsofthefamilyCyclopidae KaraytugandS.Sak). (KaraytugandBoxshall,1998a). Cyclopsstrenuus Fischer,1851:(Turkey,Seyhandam Inthispaper,weattempttoshowthattheanalysisof lake,Adana,14.10.1992,coll.S.Karaytug). thesetationpatternandhencetheestablishmentofthe Diacyclopsbicuspidatus (Claus,1857):(Turkey, homologiesofthesegmentscanbeextended,simplyby Uluabatlake,Balıkesir,09.03.2002,coll.A.Alper). applyingthesimilarprocedureperformedforthe Paracyclops species(KaraytugandBoxshall,1998a),to Eucyclopsserrulatus (Fischer,1851):(Turkey,Riva theothergeneraofthefamilyCyclopidae. creek,Ömerlivillage,‹stanbul,01.05.2001,coll.S. KaraytugandS.Sak). Ectocyclopsphaleratus (Koch,1838):(Turkey, MaterialsandMethods Yamansazlake,Antalya,06.07.2001,coll.S.Karaytug Specimensofninespeciesrepresentingeightgenera andS.Sak). werestudied.Adultfemaleswerecollectedfromdifferent Paracyclopscanadensis:(Theantennuleofthisspecies localitiesinTurkeyandtheobservationswerebasedon wasredrawnfromKaraytug&Boxshall(1998b)). thesematerialsexceptthattheantennuleofP.canadensis (Willey,1934)wasredrawnfromKaraytug&Boxshall P.imminutus Kiefer,1929:(Turkey,Karasatıpond, Keflan,Edirne,28.04.2001,coll.S.KaraytugandS. (1998b).Theantennuleswereremovedandmountedin Sak). lactophenol.Fragmentsofcoverslipwereplacedbetween theslideandthecoversliptoavoidcrushingandto facilitaterotation,whichallowedtheantennulestobe ResultsandDiscussion viewedfromallangles.Alldrawingsweremadewiththe Seventeenisthelargestnumberofsegmentsfound aidofadrawingtubeusingNomarskidifferential fortheantennulesofadultfemalesinthisstudy. interferencecontrast(DIC)attachedtoanOlympusBX50 Seventeensegmentsarefoundin Megacyclopsviridis , microscope,andanocularmicrometerwasusedtotake Macrocyclopsfuscus,Acanthocyclopsrobustus,Diacyclops measurements. bicuspidatus and Cyclopsstrenuus andthesegmental Thehomologyoftheantennularysegmentswas setationformulaforeachofthesespeciesis8,4,2,6,4, establishedbycomparingthedistributionofthesetaeon 2,2,1,1,0,1,1+aesthetasc,0,1,2,2+aesthetasc, eachexpressedsegmentwithreferencetotheirposition 7+aesthetasc.Bycomparingtheantennuleswiththe andparticularelementsrecognizedhereasmarkers(two Paracyclops antennules(KaraytugandBoxshall,1998a) arrowsandastarareinsertedintheFigure toindicate andtheantennuleofthefemale Euryterobusta these).IntheFigure,dottedlinesindicatethe Giesbrecht,1900(HuysandBoxshall,1991),the homologoussegmentsbetweentheantennules. ancestralsegments(showninRomannumeralsbelow)of the17-segmentedantennules(showninArabicnumerals) Romannumeralsthatareshowninparenthesisinthe ofthespeciesstudiedcanbeidentifiedasfollows: resultsanddiscussionsectionindicatederivationsfrom hypothetical28-segmentedancestralantennuleproposed 1(I-V),2(VI-VII),3(VIII),4(IX-XI),5(XII-XIII),6 byHuysandBoxshall(1991). (XIV),7(XV-XVI),8(XVII),9(XVIII),10(XIX),11(XX), 12(XXI),13(XXII),14(XXIII),15(XXIV),16(XXV), Speciesstudiedandcollectiondata: 17(XXVI-XXVIII).Acomparisonofthe17-segmented Megacyclopsviridis Jurine,1820:(Turkey, antennulesofthespeciesusedinthisstudywiththoseof Karamandere,Tekirda¤,30.04.2001,foundinasmall Er.robusta revealedthatthedeterminationsofsegment pond,coll.S.KaraytugandS.Sak). 7of Paracyclopswaiariki Lewis,1974asancestral 130 S.KARAYTU⁄,S.SAK,A.ALPER 17 16 15 10 9 8 7 6 5 14 13 12 11 4 3 2 1 A B C D E F G 100 A 100 B 100 C 50 D 100 E H F 50 G 50 H 50 50 J J Figure. ComparisonofadultfemaleantennulesofsomecyclopoidspeciesbelongingtofamilyCyclopidae.Antennulesareallinve ntralview.A. Megacyclops viridis;B.Macrocyclopsfuscus; C.Acanthocyclopsrobustus;D. Diacyclops bicuspidatus;E.Cyclopsstrenuus;F. Eucyclops serrulatus;G.Ectocyclopsphaleratus;H. Paracyclopscanadensis;J. Paracyclopsimminutus.Scalebarsinmm. 131 ComparisonofFemaleAntennulesinSomeGeneraofCyclopidae(Copepoda,Cyclopoida):TheirSignificanceforPhylogeny segmentXVandsegment8asancestralsegmentsXVI-XX expressedsegments(Boxshalletal.1984). byKaraytugandBoxshall(1998a)areerroneous.The Methodologically,however,polarisationofthecharacters correctidentificationshouldbeasfollows:segment7of foundontheantennulesofthespeciesusedinthisstudy P.waiariki isderivedfromancestralsegmentsXV-XVI canalsobeachievedbyoutgroupcomparisonincladistic andsegment8isderivedfromancestralsegmentsXVII- analysis(BaflıbüyükandÇıplak,1997)using,forexample, XX. theantennulesofEuryterobusta asanoutgroup. Thepatternofsetationelementsoncyclopoid Theantennulesof Eucyclopsserrulatus , Ectocyclops antennulespermitstheunequivocalidentificationofthe phaleratus, Paracyclopscanadensis and P.imminutus patternofancestralsegmentalhomologies(Karaytugand shownintheFigureexhibitoneormoresegmental Boxshall,1996,1998a).Thecommonsetationpattern fusionsbetweensegmentshomologouswiththesecond containsanumberofelementswhichactasreference andfifteenthsegmentsoftheantennulesof Megacyclops pointsalongtheantennule.Onsegment6(XIV)of viridis, Macrocyclopsfuscus, Acanthocyclopsrobustus , Megacyclopsviridis thereisaspinelocateddistally Diacyclopsbicuspidatus and Cyclopsstrenuus . (arrowedintheFigure),whichprovidesanimportant Comparativestudiesindicatethatseveralsegmental reference.Inaddition,onsegment12,theaesthetasc fusionsontheantennulesofsomespeciesexaminedcan (indicatedbyanarrowintheFigure)derivedfrom bedefinedasapomorphies:thesefusionsareasfollows: ancestralsegmentXXIprovidesanothersignificant Theconditionwherenofusionoccursbetweenthe