A New Species of the Pond Loaches Misgurnus (Cobitidae) from the South of Sakhalin Island.

A new species of pond loaches is described from the systems of Chibisanskiye–Vavaiskiye lakes in the south of Sakhalin Island. This species is distinguished from all other Misgurnus species by having a moderately deep body (maximum body depth 7.3–8.6 times in standard length, SL); poorly developed adipose crests; elongated caudal peduncle with its length usually exceeding 19% SL; caudal peduncle depth 1.9–2.4 times in length; dorsal fin begins much closer to the tip of the snout than to the end of the caudal fin; short pelvic fins with their length 1.2–1.7 times in length between the pelvic and anal fins in males and 1.7 times in females; length from pelvic fin base to anal fin base 1.9–2.4 times in the length from anal fin base to caudal fin base; more than 140 transverse rows of scales in the side series; lamina circularis rounded and flat; no distinct black spot at the upper base of the caudal fin. Analysis of several genetic markers (mitochondrial cytb and fragments of nuclear genes Rag1 and IRBP) proved that the new species is an independent phylogenetic lineage within Misgurnus, the same rank as the M. nikolskyi lineage or the group including M. mohoity and M. anguillicaudatus. [ABSTRACT FROM AUTHOR]