The complete mitochondrial genome sequence of Triplophysa stenura (Teleostei, Cypriniformes): genome characterization and phylogenetic analysis.

The nemacheilid genus Triplophysa is widely distributed in the Qinghai-Tibet Plateau and its adjacent areas. The complete mitochondrial genome of the loach Triplophysa stenura collected from the Peigucuo Lake was sequenced. The genome was 16,569 bp in length, including 13 protein-coding genes, 22 transfer RNA genes, two ribosomal RNA genes, and a non-coding control region (D-loop). Most of the genes were encoded on the heavy strand, except for ND6 and eight tRNA genes. The overall base composition of T. stenura was 27.8% for A, 28.4% for T, 25.4% for C, 18.4% for G, with a slight A + T rich feature (56.2%). Phylogenetic analyses showed that all Triplophysa species clustered together and T. stenura formed a sister relationship with T. tibetana. The complete mitogenome data of T. stenura would provide essential information in understanding phylogenetic relationships among Triplophysa species.