Description of a new troglobitic Sinocyclocheilus (Pisces, Cyprinidae) species from the upper Yangtze River Basin in Guizhou, South China

Sinocyclocheilus guiyang, a new troglobitic species from a subterranean tributary of the upper Yangtze Basin in Guiyang City, Guizhou Province, China is described in the present study. The new species is distinguishable from its congeneric species by a combination of the following characters: tip of maxillary barbel reaching to posterior edge of orbit; forehead horn absent; eye absent (or highly reduced) and tip of pectoral fins not significantly extending beyond the base of the pelvic fin. Molecular evidence, based on the mitochondrial cytochrome b (cytb) gene, further supports the validity of the species and also reveals its close relationship with S. cyphotergous, S. multipunctatus, S. punctatus and S. sanxiaensis. In addition, the new species faces a high risk of extinction, underscoring the urgency for habitat protection measures within its limited range.