Browsing by Author "Fritz, U"

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    Aspect of population structure of the European Pond Turtle (Emys orbicularis) in Lake Yayla, western Anatolia, Turkey
    Ayaz, D; Fritz, U; Atatür, MK; Mermer, A; Çiçek, K; Afsar, M
    Our main objective was to establish the population size, density, body size, and sex ratio of a local Emys orbicularis population. We examined the population structure of E. orbicularis in Lake Yayla, Buldan (Denizli), Turkey, using capture-recapture methods. The population consisted of 54% males, 42% females, and 4% juveniles. The adult sex ratio was significantly skewed in favor of males. Using the Jolly program, the population size was estimated at 1,462 (95% CI = 1,161-1,763), corresponding to a density of 81 turtles per hectare of optimal habitat. Females were larger than males. In carapace length, the Lake Yayla population resembles other small-sized populations inhabiting the southern parts of the species' range. The conservation status of the Turkish populations and their main threats are also discussed.
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    Population estimate and body size of European pond turtles (Emys orbicularis) from Pazaragac (Afyonkarahisar/Turkey)
    Ayaz, D; Fritz, U; Tok, CV; Mermer, A; Tosunoglu, M; Afsar, M; Çiçek, K
    Data on population size, adult sex ratio, body size and mass are provided for a population of the turtle Emys orbicularis near Pazaragac (Afyonkarahisar/Turkey). Using the mark-recapture method (triple catch), a population size of 664 turtles was estimated (95% confidence interval, range 332-996), corresponding to a density of 83 turtles per hectare (range 41.5-124.5). The adult sex-ratio was significantly skewed in favor of males (2.02 males: 1 female; P < 0.001). Almost all recorded specimens were adult (98.1%). Mean straight carapace length (SCL) and body mass (BM) of adult turtles were: SCL = 128.65 mm, BM = 345 g for males (n = 168) and SCL = 135.37 mm, BM = 463 g for females (n = 83).
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    Population structure and gene flow of the syntopic turtles Emys and Mauremys from coastal and inland regions of Anatolia (Turkey): results from mitochondrial and microsatellite data
    Ilhan, S; Vamberger, M; Ayaz, D; Fritz, U
    Revealing the genetic basis of the existence of different species living together in different geographic regions provides clarification of this phylogeographic differentiation. In this study, we investigated the population genetics and evaluated the level of genetic variation of inland and coastal populations of Mauremys and Emys in Turkey. Tissue samples of 196 terrapins were studied which were collected from syntopic coastal (Golbent-Soke/Aydin; M. rivulata and E. orbicularis) and inland populations (Bahcesaray/Aksaray; M. caspica and E. orbicularis). DNA was isolated using the InnuPREP DNA Mini Kit. Mitochondrial DNA sequences and allelic variation at 13 microsatellite loci for Mauremys and 12 microsatellite loci for Emys were examined. Three haplotypes were found for Emys orbicularis (Im, Ip and Iw) collected from the coastal region and two haplotypes for Emys orbicularis (Ig and Im) collected from inland. Two haplotypes were identified for M. caspica (Cmt8 and Cmt9) and three haplotypes were identified for M. rivulata (Rmt3, Rmt24 and Rmt26). Using microsatellites and the software STRUCTURE the most probable value for K was revealed as two 2 for both species. The F-ST value between M. rivulata and M. caspica was 0.39, and between the coastal and inland populations of E. orbicularis 0.09. It can be concluded that Emys populations tend to evolve by somehow preserving the allelic richness they have and Mauremys populations continue to differentiate so that new species emerge in the evolutionary process to reach the ideal allelic structure.
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    It takes two to tango - Phylogeography, taxonomy and hybridization in grass snakes and dice snakes (Serpentes: Natricidae: Natrix natrix, N. tessellata)
    Asztalos, M; Ayaz, D; Bayrakci, Y; Afsar, M; Tok, CV; Kindler, C; Jablonski, D; Fritz, U
    Using two mitochondrial DNA fragments and 13 microsatellite loci, we examined the phylogeographic structure and taxonomy of two codistributed snake species (Natrix natrix, N. tessellata) in their eastern distribution area, with a focus on Turkey. We found evidence for frequent interspecific hybridization, previously thought to be extremely rare, and for backcrosses. This underscores that closely related sympatric species should be studied together because otherwise the signal of hybridization will be missed. Furthermore, the phylogeographic patterns of the two species show many parallels, suggestive of a shared biogeographic history. In general, the phylogeographies follow the paradigm of southern richness to northern purity, but the dice snake has some additional lineages in the south and east in regions where grass snakes do not occur. For both species, the Balkan Peninsula and the Caucasus region served as glacial refugia, with several mitochondrial lineages occurring in close proximity. Our results show that the mitochondrial divergences in both species match nuclear genomic differentiation. Yet, in the former glacial refugia of grass snakes there are fewer nuclear clusters than mitochondrial lineages, suggesting that Holocene range expansions transformed the glacial hotspots in melting pots where only the mitochondrial lineages persisted, bearing witness of former diversity. On the other hand, the deep mitochondrial divergences in N. tessellata across its entire range indicate that more than one species could be involved, even though lacking micro satellite data outside of Turkey prevent firm conclusions. On the contrary, our microsatellite and mitochondrial data corroborate that N. megalocephala is invalid and not differentiated from sympatric populations of N. natrix. For Cypriot grass snakes, our analyses yielded conflicting results. A critical assessment of the available evidence suggests that N. natrix is a genetically impoverished recent invader on Cyprus and taxonomically not distinct from a subspecies also occurring in western Anatolia and the southern Balkans. Based on combined mitochondrial and nuclear genomic evidence we propose that for grass snakes the following subspecies should be recognized in our study region: (1) Natrix natrix vulgaris Laurenti, 1768, southeastern Central Europe and northern Balkans; (2) Natrix natrix moreoticus (Bedriaga, 1882), southern Balkans, western Anatolia, and Cyprus; and (3) Natrix natrix scutata (Pallas, 1771), eastern Anatolia, Caucasus region, Iran, northeastern distribution range (from eastern Poland and Finland to Kazakhstan and the Lake Baikal region). Thus, Natrix natrix cypriaca (Hecht, 1930) becomes a junior synonym ofN. n. moreoticus and Natrix natrix persa (Pallas, 1814) becomes a junior synonym ofN. n. scutata. Due to insufficient material, we could not resolve the status of Natrix natrix syriaca (Hecht, 1930) from the Gulf of Iskenderun, southeastern Turkey.