Intraspecific Taxonomy and Nomenclature of the Danube

Intraspecific Taxonomy and Nomenclature of the Danube

Intraspecic taxonomy and nomenclature of theDanube crested newt, Triturus dobrogicus SpartakN. Litvinchuk 1,2,LeoJ. Borkin 1 1 ZoologicalInstitute, Russian Academy ofSciences, 199034St. Petersburg, Russia 2 Instituteof Cytology, Russian Academy ofSciences, 194064St. Petersburg, Russia Abstract. ThePannonian and Danube Delta populationsof Triturusdobrogicus are well separated morpholog- icallyfrom each other.We recognizetwo subspecies of theDanube crested newt.The nominotypic subspecies inhabitsthe Danube Delta. Triturusdobrogicus macrosomus (Boulenger,1908), comb. and stat. nov., occurs in theremaining part of the species’ range. Introduction TheDanube crested newt has been described as a varietyof the crested newt, Triton cristatus var. dobrogicus Kiritzescu,1903, from lakesin the environsof Sulina,Tulcea and theDanube River Delta in the northern part of Dobrogeain Romania (Kiritzescu, 1903). However,the name was placedin the synonymy of thenominotypic subspecies of Triturus cristatus (“Tritoncristatus typus”— Schreiber,1912: 110; “ Molgecristata cristata ” — Nikolsky,1918: 202). W olterstorff(1923) created a newsubspecies of the crested newt underthe name “ Tritoncristatus danubialis ”.He consideredthe “ forma dobrogica” as a localDobrogean form includedin hisnew subspecies. Nevertheless, Mertens and Mü ller (1928,1940) regardedboth forms astwo different subspecies, Trituruscristatus dobrogicus and T.c.danubialis .Accordingto these authors, the former subspeciesoccurs in the DanubeDelta, and the latter is distributed over the remaining part of thespecies’ range. Someother authors (e.g., C alinescu,Æ 1931; Fuhn, 1953) did not support this opinion. They believedthat both taxa occurred in the Danube Delta. Indeed, Fuhn (1953) recognized threevarieties of thesubspecies T.c.danubialis inRomania, namely: T.c.danubialis sensu stricto, T.c.danubialis var. dobrogicus and new T.c.danubialis var. intermedia. The two former varietieswere sympatricin the Delta, with a preponderanceof the rst one.Based onthe geographic de nition of subspecies and the general similarity of danubialis and c KoninklijkeBrill NV ,Leiden,2000 Amphibia-Reptilia21: 419-430 ° 420 SpartakN. Litvinchuk,Leo J. Borkin dobrogicus,someauthors synonymized them as Trituruscristatus dobrogicus (Fuhn,1960; Mertensand W ermuth,1960; Fuhn and Freytag, 1961), a solutionthat became widely accepted. Theapplication of biochemicaland cytogenetic methods to the systematics of crested newtsover the last decades has resulted in the elevation of thesubspecies to full species rank(Bucci-Innocenti et al.,1983; Macgregor et al., 1990), and this status was evidenced bydataobtained from studieson thecontact zones of thesetaxa (W allisand Arntzen, 1989; Litvinchuket al., 1994, 1997, 1999). The new concept of the T.cristatus superspecies stimulatedre-evaluation of the taxonomic structure of the “ new”species. Recently, two subspecieswere recognizedwithin T. carnifex and T.karelinii ,respectively(Kalezi c´ et al., 1997;Litvinchuk et al.,1999). The range of T.dobrogicus consistsof two parts, restricted to the Pannonian and Dobrogeanlowlands, respectively (Arntzen et al., 1997; g.1).Based on thesmall range, relativerarity and rapid loss of habitat,Arntzen et al.(1997) considered the conservation status of T.dobrogicus asvulnerable. The species is protected by the Berne Convention (theAnnex II) andis included to the 1996 IUCN RedList of ThreatenedAnimals under thecategory “ datade cient” (Oliveira et al.,1997). Thegoal of thepresent paper is to re-evaluatethe taxonomic composition of T. dobrogi- cus andits nomenclature. Materialsand methods Westudiedthe Pannonian T.dobrogicus from threeY ugoslavianlocalities, and from eleven localitiesin the Ukrainian Transcarpathians ( ZakarpatskayaProvince). The Dobrogean D sampleswere studiedfrom fourUkrainian localities (Odessa Province) in theDanube Delta (g. 1). W ealsostudied a Moldaviansample, and a specimenwith uncertain origin (the holotype of Molgemacrosoma ). For morphometricanalysis, we used163 adult specimens of T.dobrogicus (tables 1 and2). The following characteristics were measuredwith dial callipers (to the nearest 0.1mm) for eachindividual: TL istotallength; L isbody length, from thesnout to thefront edgeof thecloacal split; Lcd is taillength, from theanterioredge of thecloacal split to the tailtip; LiE is distancebetween fore andhind extremities; Pa andPp are fore- andhindlimb length,respectively; Lc is head length, from thesnout to the border of themouth angle; Ltcis thehead width between the mouth angles. WI isthe “ WolterstorffIndex” , givenas ratiobetween Pa andLiE (in percents). Principal component analysis was performedfor bothsexes on thestandardized residuals of theregression of naturallogarithm of sizedata withSYST AT5.0(Wilkinson, 1989). Discriminant analysis was performedseparately for malesand females on thenatural logarithm of sizedata with ST ATISTICA 6.0.Lcd was removedin these analyses because of incompletenessof data. Taxonomy of Triturusdobrogicus 421 Figure 1. Distributionof Triturusdobrogicus ,withlocalities studied (1 — UkrainianTranscarpathians: Batevo, Chop,Chornyi Potok, D’ yakovo,Dobroselje, Drisina, Gat’ , MalyeGeevtsy, Minai, Mukachevo, Shalanka; 2 — Yugoslavia:Ostrovo; 3 —Yugoslavia:Radoevo; 4 —Yugoslavia:Obetska Bara; 5—Moldavia:Kagul; 6 — Odessa Province:Reni; 7 —Odessa Province:Izmail; 8—Odessa Province:Vilkovo, Leski). Anatomicalpreparations (dissection, “ dry”skeleton, alizarin treatments) and larval externalsegmentation were usedfor examinationof thenumber of rib-bearingvertebrae (atlasexcluded). Additional information about color and belly spots distribution was studiedon animals alive in the eldor in captivity, and on preserved specimens (only patterning).The total sample consisted of 320adults, 21 juvenileand 58 larvalspecimens. In1994-1997, we crossednewts representing various members of the T.cristatus superspecies;within T.dobrogicus ,animalsfrom variousparts of the range were also involved.All crosses were carriedout at room temperature (20-25 ±C)inaquaria 60-100 l volume.Eggs deposited on vegetation were collecteddaily and transferred to shallow bowlswhere development continued. Larvae were keptin identicalconditions and reared in aquaria(20-30 l volume),with density between 10 and40 larvaeper aquarium, depending onthestage of developmentand the size of animals(exclude larval cannibalism). Embryo andlarval survival rates were determinedas the number of hatchingembryos (beginning activefeeding) and metamorphosed juveniles, respectively, in relation to the number of fertilizedeggs. Results Theresults of the principal component analysis demonstrated separation of the Danube Deltaand Pannonian populations of T.dobrogicus .Inthe two-dimensional plot ( g. 2)we 422 Table 1. Variation of morphometric characters in males of the Pannonian, Moldavian and Danube Delta samples of Triturus dobrogicus. s is a standard deviation. The ratio Ltc/L is given in percents. Character Transcarpathians1 (n 19) Transcarpathians2 (n 17) Yugoslavia (n 12) Moldavia (n 2) Danube Delta (n 49) D D D D D Mean s Range Mean s Range Mean s Range Range Mean s Range TL* 117.6 2.9 115.0-120.8 99.0 – – – – – – 115.4 8.0 93.5-131.0 L 64.7 4.9 55.4-74.5 61.4 6.0 48.0-70.7 62.7 4.2 53.6-68.7 63.0-64.1 61.1 4.6 51.0-69.0 Lcd* 51.7 2.2 50.0-54.1 45.0 – – – – – – 54.1 4.5 41.5-62.0 LiE 38.2 3.8 31.1-47.7 35.5 4.8 24.8-43.8 37.8 3.5 31.9-43.1 35.9-36.8 33.9 3.0 29.2-39.8 Pa 19.4 2.2 14.3-22.5 19.2 1.7 15.7-22.0 18.7 2.4 15.0-23.4 18.6-17.0 20.2 2.2 15.3-25.0 Pp 21.1 1.9 18.0-26.0 20.7 1.8 17.0-24.0 21.0 1.9 18.0-25.0 17.0-18.0 21.6 2.2 16.0-27.0 Lc 6.2 0.5 5.4-7.0 6.3 0.4 5.7-7.4 5.9 0.4 5.3-6.7 5.9-6.2 7.0 0.6 5.8-8.5 Ltc 8.4 0.6 7.2-9.8 8.3 0.8 7.2-10.3 8.2 0.5 7.4-9.0 8.2-8.5 8.9 0.5 7.8-10.0 WI 50.9 3.6 43.0-56.7 54.4 5.0 43.6-64.5 49.6 5.0 43.3-57.1 47.4-50.5 59.6 6.2 47.1-70.5 Ltc/L 13.0 0.8 11.8-14.6 13.6 1.1 11.2-15.2 13.1 0.9 11.6-14.7 13.0-13.3 14.7 1.0 12.3-16.9 1 Samples collected in the Ukrainian Transcarpathians beyond the contact zone with T. cristatus (more than 20 km); 2 samples collected close to the contact zone; * for characters TL and Lcd, the number of specimens examined from Transcarpathians1 are equal to 3, Transcarpathians2 is 1, Danube Delta is 48. Table 2. Variation of morphometric characters in the holotype of Molge macrosoma and females of the Pannonian, Moldavian and Danube Delta samples of Triturus dobrogicus. Character Holotype Transcarpathians1 Transcarpathians2 Yugoslavia Moldavia Danube Delta (n 11) (n 19) (n 5) (n 1) (n 27) D D D D D Mean s Range Mean s Range Mean s Range Mean s Range pra Spartak TL* 183.9 – – – 125.9 6.0 125.0-132.0 – – – – 120.9 14.4 95.0-152.5 L 96.7 74.3 5.9 65.2-83.3 66.4 5.6 54.0-74.9 69.7 6.9 63.2-78.0 65.8 64.5 7.5 52.5-83.1 Lcd* 87.2 – – – 56.6 0.9 55.5-57.5 – – – – 56.5 7.1 42.0-71.0 N. LiE 61.7 46.2 3.4 40.0-52.8 40.7 4.3 31.0-50.0 42.9 5.2 36.0-49.6 40.0 38.0 4.9 29.0-52.3 Litvinchuk, Pa 26.2 18.0 1.7 15.0-20.0 17.4 1.2 15.0-19.3 17.8 1.6 16.1-20.0 15.0 17.2 2.1 12.2-21.5 Pp 26.0 18.6 1.1 17.0-20.0 18.6 1.7 16.0-21.0 18.6 1.5 17.0-20.0 17.0 18.0 2.2 13.0-23.0 Lc 7.5 6.6 0.5 5.9-7.4 6.4 0.5 5.6-7.6 6.3 0.6 5.8-7.1 6.1 6.9 0.7 5.7-8.0 Ltc 12.1 8.7 0.7 7.5-9.9 8.4 0.5 7.8-9.3 8.4 1.0 7.3-9.4 8.0 9.3 0.9 7.5-11.0 Leo WI 42.5 38.9 2.2 34.9-41.5 43.2 3.3 36.6-50.0 41.8 4.9 37.3-49.7 37.5 45.7 4.9 39.7-60.7 .J.

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