Morphological variation of the Common Lizard (Zootoca vivipara Jacquin, 1787) in the Central Balkans

The variation in some of the morphometric, meristic and qualitative characters of the Common Lizard (Zootoca vivipara) in five population samples from mountains of the Central Balkans was analyzed using univariate and multivariate statistics. The morphological differentiation was greater in males than in females and is more expressed in the morphometric than in the pholidosis and qualitative characters. The largest differences in morphometric traits appeared between the populations from the Šara and Stara Planina mountains. The 'median' pileus pattern generally prevailed, with the appearance of other states in a certain proportion in some of the populations. Further analyses of the possible morphological and ecological distinctions of the population from Mt Tara are proposed.

Morphing of the phylogeographic lineages of the Balkan alpine newts (Ichthyosaura alpestris, Caudata, Salamandridae): In situ morphological diversification

Numerous alpine newt (Ichthyosaura alpestris) populations from the Balkans, representing all the previously established phylogeographic lineages, were studied for variations in various morphological characteristics (body size and shape, skull qualitative traits and number of trunk vertebrae). Here, we present a decoupling of morphological and mtDNA phylogeographic substructuring in the alpine newt on the Balkan Peninsula. In sharp contrast to other European newts (Triturus spp., Lissotriton spp.), the vast majority of morphological variation in the alpine newt is concentrated at the population level indicating an in situ morphological diversification. We found that the rate of morphological change is similar to the rate of mtDNA change. We hypothesize that the alpine newts are characterized by non-adaptive morphological evolution. © 2011 Academie des sciences. Published by Elsevier Masson SAS. All rights reserved

Evolutionary and paleogeographical effects on the distribution of the Triturus cristatus superspecies in the central Balkans

A synthesis of all known data on the crested newt group assigns the Balkan peninsula as the center of origin or, at least, the area where the basic lineage of its species was limited in the late Miocene. According to the recent literature, the geological structure of the Balkan region changed considerably during the Tertiary. These geological processes could have had a considerable impact on crested newt divergence and on the recent distribution of species. Using the number of rib-bearing vertebrae (RBVN), recently suggested as a simple and powerful tool for distinguishing four taxa of the T. cristatus superspecies, we analysed 36 population samples collected all over former Yugoslavia. The hypothesised recent distribution of the crested newt species, based on frequency distribution of RBVN, appears to correspond well to neotectonic events in the past

Skull size and shape variation versus molecular phylogeny: A case study of alpine newts (Mesotriton alpestris, Salamandridae) from the Balkan Peninsula

We explored the phylogenetic signal of skull size and shape in alpine newts from the Balkans, a group of European newts that, in spite of their considerable phylogeographic substructuring (as inferred from previous DNA analyses), maintain a conserved phenotype. In terms of skull shape disparity, geometric morphometrics show that the dorsal cranium carries a significant phylogenetic signal, the most notable evidence in this present study. On the contrary, no phylogenetic signal in the shape of the ventral cranium was found. This result indicates that the variation in the shape of the ventral cranium is more prone to other factors and processes, such as adaptations to local environments rather than phylogenetic constraints. Variation in skull size within alpine newts seems to be independent from phylogenetic constraints. © 2009 Springer-Verlag

Phylogeny and biogeography of the alpine newt Mesotriton alpestris (Salamandridae, Caudata), inferred from mtDNA sequences

In this paper, we performed phylogenetic analyses of Mesotriton alpestris populations from the entire range of species distribution, using fragments of two mtDNA genes, cytochrome b (309 bp) and 16S rRNA (∼500 bp). Sequence diversity patterns and phylogenetic analyses reveal the existence of a relict lineage (Clade A) of late Miocene origin, comprising populations from south-eastern Serbia. This lineage is proposed to be ancestor to a western and an eastern lineage, which diverged during the middle Pliocene. The western lineage is further divided in two clades (Clades B, C) of middle Pliocene origin that represent populations from Italy (B) and populations from central Europe and Iberia (C). Further subdivision, dated back to the middle-late Pliocene, was found within the eastern lineage, representing southern (Clade D) and central-northern (Clade E) Balkan populations, respectively. Extensive sequence divergence, implying greater isolation in multiple refugia, is found within eastern clades, while the western clades seem to have been involved in the colonization of central, western and north-eastern Europe from a hypothetical refugium in central Europe. The extent of divergence does not support the current taxonomy indicating cryptic speciation in the Balkans, while paedomorphic lineages were found to have been evolved during early-middle Pleistocene probably as a response to the ongoing dramatic climatic oscillations. © 2007 Elsevier Inc. All rights reserved

The evolution of the adult body form of the crested newt (Triturus cristatus superspecies, Caudata, Salamandridae)

We characterized the adult body form of the crested newt (Triturus cristatus superspecies) and explored its evolution. From seven morphometric traits, we determined that body size, interlimb distance and head width define the body form. None of the morphometric traits showed a phylogenetic signal. Three body-shape morphotypes (Triturus dobrogicus+T. cristatus, Triturus carnifex+Triturus macedonicus and Triturus karelinii+Triturus arntzeni) and three body-size morphotypes (T. dobrogicus, T. cristatus and all other crested newts) could be recognized. The ancestral phenotype (a large body with a short trunk and a wide head) characterized T. karelinii and T. arntzeni. Triturus carnifex and T. macedonicus had a somewhat different phenotype (large body and wide head, accompanied by mild body elongation). The most derived phenotype included body size reduction and more pronounced body elongation in T. cristatus and, especially, in T. dobrogicus. Body elongation occurred by trunk lengthening but not head and tail lengthening. Additionally, contrary to other tetrapods, evolutionary axis elongation in crested newts was followed by a decrease in body size. We advocate the hypothesis that ecology drives the evolution of body form in crested newts. © 2011 Blackwell Verlag GmbH

Biogeography and ecology of paedomorphosis in Triturus alpestris (Amphibia, Caudata)

Aim Paedomorphosis is an evolutionary change in which larval structures are retained in adult animals. In newts and salamanders, this heterochronic process is widely represented and concerns the retention of gill slits. We want to find out whether ecological and geographical determinants may be associated with paedomorphosis in the Alpine newt Triturus alpestris. Location Europe. Methods Determination of the main characteristics of all known aquatic sites containing paedomorphic Alpine newt individuals. Results Although metamorphs are common in Europe, paedomorphs are only found at the southern margin of the geographical range of the species: mainly in Italy and in the Balkans. They were recorded in eighty-seven aquatic sites. No single trend was outlined for the analysed ecological parameters of the aquatic and terrestrial habitats (e.g. altitude, maximum water depth, drying and presence of forest). Main conclusions Contrary to the first models of paedomorphosis, the main traits of aquatic and terrestrial habitat do not explain the occurrence of paedomorphs in natural populations. Although they were found in favourable aquatic habitats surrounded by hostile terrestrial landscapes, they also exist in temporary waters located at proximity of appropriate terrestrial environments. These results support models predicting paedomorphosis in varied environments, but require complementary investigations on the costs and benefits of the alternative ontogenetic pathways. On the other hand, the southern limitation of the heterochronic phenomenon suggests a genetic basis for paedomorphosis in the studied species

Morphology of the smooth newt (Triturus vulgaris) in former Yugoslavia: Taxonomical implications and distribution patterns

The morphological traits of the smooth newt, Triturus vulgaris (LINNAEUS, 1758), have been studied in a considerable number of population samples from former Yugoslavia, taxonomically the most intriguing area of the Balkans. We found a great deal of variation in various morphological traits, more than previously thought, including those used to delimit subspecies. However, relevant taxonomic conclusions could be suggested from such variability patterns. We reaffirmed the possibility of the existence of two separate population groups within the range of the T. v. graecus subspecies. One group occurs in the area of southern Herzegovina and Montenegro, which was described a long time ago as the tomasinii form or subspecies (T. v. tomasinii). The other group is from the Former Yugoslav Republic of Macedonia (T. v. graecus sensu stricto). Rather broad intergradation zones of tomasinii x T. v. vulgaris and T. v. meridionalis x T. v. vulgaris were determined. The former zone occurs mostly in the Oromediterranean part of the Dinaric Alps. It was found that the ranges of the smooth newt subspecies followed the Balkan zoogeographical divisions to some extent.nul

A phylogenetic view on skull size and shape variation in the smooth newt (Lissotriton vulgaris, Caudata, Salamandridae)

In this study, we explore skull size and shape variation in the smooth newt, a taxon with substantial morphological differentiation and complex phylogeographic relations. By projecting phylogenies into the morphospace of the skull shape, we explore the variation in and differentiation of this complex morphological structure within a phylogenetic framework. For these analyses, we used a dataset that covers the most southern part of the species' distribution range, including all conventionally recognized subspecies. The study revealed different patterns of divergence in skull shape between sexes, which is paralleled by intraspecific differentiation. The divergence in dorsal skull shape is concordant with the phylogenetic divergence, as the most diverged clades of the smooth newt (Lissotriton vulgaris kosswigi and Lissotriton vulgaris lantzi) exhibit a skull shape that significantly diverges from the smooth newt's mean shape configuration. The results of this study also indicate that ventral skull portion, which is more directly related to feeding and foraging, shows higher variation between populations than dorsal skull portion, which appears to be less variable and phylogenetically informative. © 2011 Blackwell Verlag GmbH