Dynamics of Diversity of Spined Loaches of Genus Cobitis, Inhabiting Caucasus, during the Anthropogenic Period According to the Data of Museum Collections. I. Morphological Variability and Diagnostic Characters of Cobitis saniae (Cobitidae)

The variability of morphological characters and coloration features used for identification of the species Cobitissaniae has been studied using the materials from the collection of the Zoological Museum of Lomonosov Moscow State University, which includes voucher samples with genetically confirmed species status, in order to clarify the dynamics of the diversity of spined loaches in Transcaucasia in the anthropogenic period. Significant variability of many characteristics at the intraspecific level has been revealed. Previously proposed taxonomic keys do not allow to identify correctly C. saniae and C. faridpaki, which are accepted in the status of cryptic allopatric species differentiated by the analysis of the mitochondrial genome. The characters are suggested that make it possible to differentiate C. saniae from C. taenia and C. melanoleuca, inhabiting the basin of the Caspian Sea, and from two species known from water bodies within the modern range of C. saniae: Khvalynskaya spined loach C. amphilekta, common in the basin of the Kyzylagach Bay in the 1930s, and a new species C. derzhavini described from the Kura River basin.