Two new species of the loach genus Homatula Nichols, 1925 (Pisces, Nemacheilidae) from the upper Chang-Jiang Basin in China

Two new species of Homatula are herein described from the Wu-Jiang of the upper Chang-Jiang Basin in Guizhou Province, China. Homatula xiangzhi and H. shexiang are respectively assigned to the scaleless group and the partially scaled group of the genus. Homatula xiangzhi differs from all other species of the scaleless group in having a complete lateral line, an adipose crest along the dorsal mid-line of the caudal peduncle anteriorly terminating behind the middle of the anal-fin base, nine branched dorsal-fin rays, vertebrae 4+42-43 and no median notch on the lower jaw. Homatula shexiang is similar to H. longidorsalis in having nine branched dorsal-fin rays rather than seven or eight in all other species of the partially scaled group, but differs from it in having an adipose crest along the dorsal mid-line of the caudal peduncle anteriorly terminating behind the middle of the anal-fin base, a deeper head and a slender caudal peduncle. The validity of the two new species is further corroborated in a molecular phylogenetic analysis, based on the Cytb gene.