Abstract
Two new species of the genus Sineuchiloglanis are described from two tributaries of the upper Yangtze River, China. These two new species can be distinguished from all congeners by morphological comparisons and phylogenetic analysis. Sineuchiloglanis chishuiensis sp. nov. can be distinguished from its congeners by the combination of the following characters: eye enlarged, with diameter 6.8-9.1% of head length (HL); interorbital width 24.1-24.8% of HL; maxillary barbel length 67.1-84.4% of HL; caudal-peduncle depth 27.1-40.3% of caudal-peduncle length; dorsal-fin rays i, 5(1/2); anal-fin rays i, 4(1/2); caudal-fin rays i, 7+8, i; gill opening extending to the base of second to third pectoral-fin elements; tip of nasal barbel not reaching anterior orbital margin; pelvic-fin tip reaching or extending beyond anus; and the abdomen slightly convex in profile. Sineuchiloglanis baishuiensis sp. nov. can be distinguished from its congeners by the combination of the following characters: head depth 42-48.4% of HL; maxillary barbel length 65.9-82.1% of HL; caudal-peduncle depth 25.9-40.6% of caudal-peduncle length; dorsal-fin rays i, 5(1/2); anal-fin rays i, 4(1/2); caudal-fin rays i, 7+8, i; gill opening extending to the base of the fourth to fifth pectoral-fin elements; tip of maxillary barbel not reaching the lower corner of the gill opening; tip of nasal barbel not reaching anterior orbital margin; and the abdomen flattened in profile. Molecular phylogenetic analysis inferred from mitochondrial Cytb gene sequences supported the validity of these two new species.