C-heterochromatin and NOR distribution in the karyotype of Persian water vole, Arvicola persicus (Mammalia; Rodentia) from Iran

Although recent molecular data has advocated the distinct position of Arvicola persicus De Filippi from Iran, karyotypic and differential chromosome staining data, informative tools to describe biological diversity, are lacking. Here we present the first description of the chromosome complement of A. persicus from its type locality in Sultaniyeh, southern Alborz Mountains, Iran. Though the diploid chromosome number (2n= 36) and the fundamental number of autosomal arms (FNa= 60) did not deviate from that reported for Arvicola amphibius sensu lato in Eurasia (2n= 36, FNa= 60–68), there appear to be significant differences between A. persicus and A. amphibius s.l. in terms of C-bands and NOR-bearing autosomes. Banded karyology, therefore, provides further evidence for delimiting A. persicus as a species, which is distinct from A. amphibius.