A New Species of Golden Loach (genus Sabanejewia, Cobitidae) from the Sea of Azov Basin

A new species of golden loach is described from the Don River basin. This species is distinguished from all other Sabanejewia species by the following set of characters: a midlateral row of relatively large 9–16 (more often 13–14) dark blotches along flank usually well developed; no black line along flank; interspaces between midlateral blotches usually with dark pigmentation; some individuals with uniform dark lateral coloration; dorsal fin origin usually in front of pelvic fin origin; body relatively low: body depth noticeably less than the length of the caudal peduncle, usually does not reach 17% standard length—SL, it is contained more than 6 times in SL; dorsal adipose crest on caudal peduncle very weakly developed, ventral crest poorly visible; two black spots at caudal fin base usually merge with each other. Previously, this species was considered conspecific for S. baltica distributed in the Black and Baltic Sea basins, but recent phylogenetic studies have shown that they belong to separate mtDNA phylogenetic lineages