Phenotypic and geographic variation among populations of the Platyceps rhodorachis-ventromaculatus species complex (Ophidia: Colubridae) in Iran

Geographical diversity appears in the phenotype of different populations of a given species and specific geographical factors are directly or indirectly involved in this variation. Due to their wide distribution range, snakes of the genus Platyceps Blyth, 1860 are wonderful case studies for morphological evaluation. In this study, 49 specimens of the Platyceps rhodorachis-ventromaculatus species complex in four different geographic areas from Iran were examined using morphological characters. The results of statistical analysis did not show any sexual dimorphism except in the character of Gular scales (P value = 0.038), but did show significant variation in the number of scales and in other morphological characters among populations in this group. Generally, four morphological clusters were distinguished with Sistan and Baluchistan population being the most distinct from the others. Additionally, there was a visible slope of changes in some morphological characters associated with latitude, so that body size of the specimens increases with increasing latitude.