Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: Sergé Bogaerts x
  • Search level: All x
Clear All
In: Amphibia-Reptilia

Abstract

Five new locations of N. strauchii are reported from Turkey, closing the gap between the two subspecies N. s. barani and N. s. strauchii. A molecular analysis based on 829 base pairs from two mitochondrial ribosomal genes (12S and 16S rRNA), together with geographical data from the area concerned, indicate all new populations found are very closely related to the mitochondrial sequences from specimens of N. s. strauchii from its type locality and suggest the river Euphrates might have acted as a natural barrier separating the only populations of N. s. barani known to date from all other populations of N. s. strauchii. A morphological analysis of all N. strauchii populations sampled for this study indicates that belly patterns are not a good diagnostic character to differentiate between N. s. barani and N. s. strauchii, suggesting the only reliable morphological taxonomic character that allows their identification is the different number of yellow spots in adult specimens, which is significantly higher in N. s. strauchii. The analyses also indicate that the number of spots is similar between sub-adult and adult N. s. barani but significantly different between sub-adult and adult specimens of N. s. strauchii, suggesting there is also a difference between both subspecies in increase in the number of spots during maturation.Listed by IUCN as vulnerable and protected by the Bern Convention (1979), our findings indicate N. s. strauchii is more widely distributed than previously thought, while N. s. barani would be restricted to just a few localities. Disturbance of its prime habitat, mountain brooks, and uncontrolled illegal collection, especially of N. s. barani, are still the main threats to the Anatolia newt throughout its known distribution range.

Full Access
In: Amphibia-Reptilia

The study of trophic ecology of terrestrial salamanders is central for a better understanding of their adaptability and dispersal, in particular in Mediterranean ecosystems where their feeding activity is reduced because of prolonged arid periods. Terrestrial salamanders are generalist predators that feed on a large array of invertebrate prey groups, however, there are few studies comparing the feeding strategy and the trophic specialization at the individual level in conspecific populations of salamanders living in different habitats. In this study, two populations of the Sardinian endemic salamander Speleomantes imperialis were sampled in areas characterized by different climate, vegetation and geological substrate. Dietary habits, obtained by stomach flushing, and physiological condition, assessed through a body condition index, were analysed and compared between populations. The two populations displayed different diets on the basis of the taxonomic composition of prey categories, but both of them behaved as generalist predators and shared a similar body condition index. Moreover, in both populations the indices of individual trophic specialization were significantly different from null models assuming a random prey distribution among predators. Therefore, the two populations were largely composed by individually specialized salamanders. Overall, these findings are in good agreement with other studies on the trophic ecology of top predators and in particular of terrestrial salamanders. The realized trophic strategies, i.e. generalist at the population and specialist at the individual level, were highly consistent geographically and the two populations exploited the different arrays of prey found in their environments similarly.

In: Animal Biology

The North African fire salamander, Salamandra algira, is distributed in Algeria, Morocco and Ceuta (Spanish territory located on the north coast of Africa), but until now rather limited information has been available on the populations across the Algerian part of its range. We here provide a first analysis of the phylogeography of this species in Algeria, based on 44 samples from populations distributed across 15 localities in Central Algeria. We sequenced three segments of mitochondrial DNA, covering 12S rRNA, cytochrome b (Cytb) and the D-loop. The mtDNA sequences of the Algerian samples were strongly different from the Moroccan populations occurring west of the Moulouya River (corresponding to the subspecies S. a. tingitana and S. a. splendens) but sister to the genetically rather similar population from the Beni Snassen Massif in eastern Morocco (subspecies S. algira spelaea). Among the Algerian specimens studied, those from the westernmost site, Chrea Massif, were the sister clade to the remaining populations, and the overall genetic divergence was low, with a maximum of five mutational steps in a 295 bp fragment of cytochrome b.

Full Access
In: Amphibia-Reptilia

Painted frogs (Discoglossus) contain five to six species of Western Palearctic anurans that are mainly distributed in allopatry. We here provide the first comprehensive assessment of the phylogeography of the Moroccan species D. scovazzi and geographically characterize its contact zone with D. pictus in Eastern Morocco. Discoglossus scovazzi shows, in general, a weak phylogeographic structure across Morocco on the basis of mitochondrial DNA sequences of the cytochrome b gene, with only populations centered in the Atlas Mountains characterized by the presence of slightly divergent haplotypes. In eastern Morocco, all populations east of the Moulouya River were clearly assignable to D. pictus. This species was also found along the Mediterranean coast west of the Moulouya, in the cities of Nador and Melilla, suggesting that not the river itself but the wide arid valley extending along much of the river (except close to the estuary) acts as a possible distributional barrier to these frogs. No sympatry of D. scovazzi with D. pictus was observed, and all specimens were concordantly assigned to either species by DNA sequences of cytochrome b and of the nuclear marker RAG1. Species distribution models of the two taxa show largely overlapping areas of suitable habitat, and the two species’ niches are significantly more similar than would be expected given the underlying environmental differences between the regions in which they occur. Comparative data are also presented from the southern Iberian contact zone of D. galganoi galganoi and D. g. jeanneae. These taxa showed less clear-cut distributional borders, extensively shared RAG1 haplotypes, and had instances of sympatric occurrence on the basis of cytochrome b haplotypes, in agreement with the hypothesis of a yet incomplete speciation. In this wide contact zone area we found mitochondrial sequences containing double peaks in electropherograms, suggesting nuclear pseudogenes or (less likely) heteroplasmy, possibly related to the ongoing admixture among the lineages.

Full Access
In: Amphibia-Reptilia