Morphological and genetic diversity of Eichwald Toad, Bufo eichwaldi in marginal populations of the east and west Caspian Sea lowland

Abstract

The Eichwald Toad, Bufo eichwaldi is one of the endemic amphibians distributed throughout Hyrcanian forests, marshes, wetlands, and streams in the north of Iran and the south of Azerbaijan. Populations of B. eichwaldi have previously been studied based on a few molecular and morphological data. Here, we undertake taxonomic and phylogenetic analyses based on morphological and morphometric features for 56 specimens of B. eichwaldi from Iran, and mitochondrial cyt b marker for 20 specimens from the whole species range in the west and east Caspian Sea lowland. Molecular analyses based on 794 bp of cyt b gene demonstrated two clusters: the east Caspian Sea lowland (A1) and the west Caspian Sea lowland (A2) clusters. Univariate analyses indicated six out of 25 morphometric variables in male B. eichwaldi specimens from the east (A1) are significantly different from male specimens of B. eichwaldi from the west Caspian Sea (A2; P≤0.05). Females have been also significantly different between two clusters in one character (distance between lids; P≤0.05). Sexual size dimorphism was also significantly different within and between populations in some variables. However, the PCA analyses show no differentiation among B. eichwaldi populations in the east and west Caspian Sea lowland. Based on p-distance parameter, the east and west groups showed a low level of genetic differentiation (0.2%).