The group of crested newts distributed from the southern Balkans to the southern shore of the Caspian Sea, Triturus karelinii sensu lato, comprises two species, T. karelinii in the east and T. arntzeni in the west. Three hypotheses have been forwarded defining the range of T. arntzeni, namely from northern Serbia eastwards i) in to Thrace, ii) up to the Aegean-Black Sea waterway including the Bosporus, or iii) into western Anatolia. We study 130 newts from 22 populations across this area with a panel of 40 enzyme nuclear genes. A combined analysis with the computer programs Structure and NewHybrids reveals the existence of two groups with admixture at two localities. The 'western group' comprises all European populations and a population at the southern shore of the Sea of Marmara in Asiatic Turkey, whereas the 'eastern group' is found at the Sakarya river valley in northern Anatolia, Asiatic Turkey. The admixed populations are also located in northern Anatolia. An analysis with the computer program BAPS resolves six genetic clusters, of which three represent the 'western group' and the other three coincide with the 'eastern group' and the two admixed populations. These analyses indicate that the species transition from T. arntzeni to T. karelinii is not in Thrace but in northern Anatolia. The presence of 'western' T. arntzeni to the east of 'eastern' T. karelinii indicates that the species' contact zone has a convoluted shape. Moreover, the spatial distribution of diagnostic allozymes only roughly coincides with that of two deeply divergent mitochondrial DNA haplotypes. A more detailed survey on the crested newt distribution in Anatolia is required to elucidate the picture further.
The Danube crested newt Triturus dobrogicus has been proposed to comprise two subspecies: T. d. dobrogicus and T. d. macrosoma. Uncertainty exists in the literature over their distribution and diagnosability. We conduct a multilocus phylogeographical survey and review published data to determine whether a two taxon treatment is warranted. Newly produced and published nuclear DNA data suggest intraspecific variation in the Pannonian Plain part of the range, but with extensive genetic admixture, whereas mitochondrial DNA data shows a lack of geographical structuring in T. dobrogicus altogether. None of the studied morphological characters suggest the presence of two geographical groups in T. dobrogicus unequivocally. Although Danube Delta newts do have relatively short bodies compared to the remainder of the range (the Pannonian and Lower Danube Plains and the Dnepr Delta), we argue that this finding can be explained by phenotypic plasticity – particularly in light of the incongruent evolutionary scenario suggested by genetic data. We conclude that the total body of evidence does not support the two subspecies hypothesis and recommend that T. dobrogicus is treated as a monotypic species.
The integration of multilocus datasets and species distribution modelling in phylogeography allows for the reconstruction of more detailed historical biogeographical scenarios than based on mtDNA data alone. We here combine these approaches to investigate the range dynamics of the crested newt Triturus karelinii, an amphibian species endemic to the Pontocaspian region, whose range comprises three allopatric range sections: a Crimean, a Caucasian and a Caspian range section. In a previous mtDNA phylogeographical survey it was suggested that the Caucasian range section was colonized from the Caspian one and that the Crimean range section was subsequently colonized from the Caucasian one. Newly collected nuclear DNA data reveal little genetic differentiation between the three range sections and species distribution modelling suggests that they only recently became isolated. Taken together, our analyses agree with a recent colonization of the Crimean range section, but rather suggest long-term persistence in both the Caspian and Caucasian range sections, with extensive gene flow between the two.
In the recently published New Atlas of Amphibians and Reptiles of Europe (Sillero et al., 2014a), the distribution of the newt genus Triturus was not resolved at the level of the species. The main reason for this was the lack of high quality distribution data from in and around the parapatric contact zones between species, where interspecific hybridization occurs. We are working extensively on Triturus and the (particularly genetic) data we have accumulated allow us to map the individual Triturus species at the appropriate scale. We here provide a database composed of distribution data for the individual species, at generally high resolution, particularly from in and around contact zones. Based on this database we produce maps at the 50 × 50 km UTM grid resolution as used in the new atlas and highlight those grid cells in which more than one Triturus species occurs.
The ‘smooth newt’, the taxon traditionally referred to as Lissotriton vulgaris, consists of multiple morphologically distinct taxa. Given the uncertainty concerning the validity and rank of these taxa, L. vulgaris sensu lato has often been treated as a single, polytypic species. A recent study, driven by genetic data, proposed to recognize five species, L. graecus, L. kosswigi, L. lantzi, L. schmidtleri and a more restricted L. vulgaris. The Carpathian newt L. montandoni was confirmed to be a closely related sister species. We propose to refer to this collective of six Lissotriton species as the smooth newt or Lissotriton vulgaris species complex. Guided by comprehensive genomic data from throughout the range of the smooth newt species complex we 1) delineate the distribution ranges, 2) provide a distribution database, and 3) produce distribution maps according to the format of the New Atlas of Amphibians and Reptiles of Europe, for the six constituent species. This allows us to 4) highlight regions where more research is needed to determine the position of contact zones.