The complete mitochondrial genome of Triplophysa lixianensis (Teleostei: Cypriniformes: Balitoridae) with phylogenetic consideration

• In this study, the complete mitochondrial genome sequence of Triplophysa lixianensis was determined.
• The sequences of all 22 tRNA genes of T. lixianensis can fold into the standard cloverleaf secondary structure.
• The phylogenetic status of T. lixianensis was confirmed.
• We proved that Triplophysa and Hedinichthys can not unit as a same genus used the mitochondrial genome sequences.

The complete mitochondrial genome of Triplophysa lixianensis was 16,570 bp in size and consisted of 13 protein-coding genes, 22 transfer RNA (tRNA) genes, two ribosomal RNA (rRNA) genes as well as a control region. The gene arrangement, nucleotide composition, and the codon usage pattern of the mitochondrial genome of T. lixianensis were similar to those of other kinds of teleosts. Nucleotide composition of the whole mitogenome was 27.81% A, 28.45% T, 25.36% C, and 18.38% G. All protein-coding genes initiated with a typical ATG start codon except for COXI, which was started with GTG. Meanwhile, seven of the protein-coding genes shared the TAA or TAG as the stop codon, the other six utilized the incomplete stop codon TA or T. All tRNA genes can be folded into the typical cloverleaf structure. Phylogenetic trees, which were based on the 12 concatenated protein-coding genes, were constructed using the Bayesian and maximum likelihood methods. The result showed that the molecular genetic position was identical to the traditional taxonomy.