Determination and comparison of two complete mitochondrial genomes of golden Chinese loach, Sinibotia superciliaris (Teleostei, Cypriniformes).

The golden Chinese loach, Sinibotia superciliaris (Günther, 1892) is an endemic fish in China, which is only distributed in the main river and tributaries of the upper and middle Yangtze River. In this study, we sequenced two mitochondrial genomes simultaneously from two samples of S. superciliaris collected from two different locations. Both mitogenomes were 16,572 bp in length, showing a typical vertebrate mitogenome feature with 13 protein-coding genes, 22 transfer RNAs, 2 ribosomal RNAs, and 1 major non-coding control region (CR). Alignment and comparative analyses showed that the two mitogenome sequences possessed 22 mutation sites, all of which were transitions and mainly occurred in protein-coding genes (13/22) and CR (7/22). Among the 13 mutation sites that occurred in protein-coding genes, three mutation sites occurred in the first codon position and the remaining 10 sites occurred in the third codon position. However, only one mutation that occurred in the first codon position resulted in non-synonymous substitution in COI gene. The molecular data presented in this study will contribute to further phylogenetic analyses for this group of fishes.