The complete mitochondrial genome of Sarcocheilichthys davidi and its phylogeny

Sarcocheilichthys davidi is a small-size ornamental freshwater species. In the present study, the complete mitochondrial genome of S. davidi was first determined using the next-generation sequencing technology. The result showed that the circular mitogenome was 16,675 bp in length, contained 13 protein-coding genes (PCGs), two ribosomal RNA (rRNA) genes, 22 transfer RNA (tRNA) genes, and two non-coding regions: origin of light-strand replication (OL) and displacement loop locus (D-loop). In addition to ND6 and eight tRNA genes, most mitochondrial genes were encoded on the heavy strand. Furthermore, the overall base composition was 29.97% A, 26.12% T, 26.86% C, 17.04% G, respectively, and showed AT-rich feature (56.09%). Moreover, phylogenetic analysis based on the tandem 13 PCGs nucleotide sequences indicated that S. davidi had a close relationship with S. snigripinnis and S. variegatus wakiyae. The complete mitogenome sequence of S. davidi would contribute to the better understanding of molecular systematics, selection, conservation, species identification and evolution of this species.