Balitora tiandengensis (Teleostei, Balitoridae), a new species of cave-dwelling loach from Guangxi, China.

Balitora tiandengensis (Teleostei, Balitoridae), a new species collected from a karst cave at Dukang Town, Tiandeng County, Guangxi, China is described and illustrated on the basis of morphological and molecular evidence. Phylogenetic trees reconstructed based on 70 sequences of two mitochondrial (COI and Cyt b) and three nuclear genes (RAG1, IRBP, and EGR2B) show that the new species represents an independent evolutionary lineage. Morphologically, Balitora tiandengensis Nong & Wei, sp. nov. can be distinguished from the other species currently assigned to the genus Balitora by its dorsal fin iii-9, anal fin i-6, pectoral fin v-12, and caudal-fin 19 branched rays. The lips exhibit no complex folding or thickening, maintaining a relatively thin and simple structure. Upper and lower lips connected at corner of mouth, upper lip with a row of inconspicuous papillae, and lower lip thin. Dorsal fin long, 16.7-19.4% of standard length (SL), anal fin short, 15.0-16.7% of SL, distal margin truncated, origin close to the anus and far from the caudal-fin base, pectoral fin 18.4-20.5% of SL, pelvic fin moderately developed, distal margin rounded, 15.1-16.7% of SL. Anus 72.5%-73.3% distance from posterior end of the pelvic fin base to the anal fin origin. The new species will help to define the new distribution of the genus Balitora in Guangxi, China.