Investigation of the morphological variation in Caucasian brown frog (Rana macrocnemis, Boulenger, 1885) in Iran

Rana macrocnemis, the Caucasian brown frog, is found in northwest and west Iran. Despite their vast distribution range, the Iranian populations of the brown frogs, with the exception of a limited number, have not been considered in studies. In this study, we used a broad sampling of these frogs across their distribution range to assess their morphological variation and structure of populations. In order to investigate the morphological variation in Caucasian brown frog, 13 morphological characters in more than 85 specimens from various regions of Iran were studied. Statistical significance for a hypothesis of sexual dimorphism of the frogs was tested using ANOVA to compare difference of means of each character between sexes and applying a multivariate analysis of variances (MANOVA) to compare vectors of means of the two sexes. Patterns of phenetic relationships between local populations were investigated by One-way ANOVA, Principal Component Analysis (PCA), Discriminant Function Analysis (DFA) and clustering analyses with UPGMA algorithm. Results of ANOVA between sexes in R. macrocnemis showed statistical significance for six characters and Multivariate analysis of variances indicated difference between mean vectors of the males and females (P≤ 0.05). In the intraspecific level, based on morphometric characters, there are at least two main populations of R. macrocnemis in the northern Iran: a northern group (Tabriz, Ardebil) and a southern group (Lorestan, Kermanshah, Arak, Hamadan, Urmia, Kordestan and Esfahan).