Caspian Spined Loach Sabanejewia caspia: Well-Known but Practically Unexplored Species of the Cobitidae Family: Peculiarities of Morphology, Karyotype, Distribution, and Postulated Phylogenetic Links

Abstract

An illustrated description of the features of the external morphology, coloration (taking into account variability), the structure of the cranium, and the karyotype of the Caspian spined loach Sabanejewia caspia are presented. As a result of a comparative analysis based on the study of collections for closely related species and literature data, a new species diagnosis of S. caspia was compiled, which allows one to avoid erroneous species identification. Confirmed data on species distribution are presented. The current state of the problem of assessing the phylogenetic relationships of S. caspia and other Sabanejewia species is discussed. Doubts about the correctness of attribution of the AU059338 and AU059339 Genbank haplotypes (widely used in phylogenetics of Cobitidae) to the species S. caucasica are substantiated.