Complete mitochondrial genome analysis of Japanese Spanish mackerel (Scomberomorus niphonius) with phylogenetic consideration

The complete mitochondrial DNA (mtDNA) of Japanese Spanish mackerel (Scomberomorus niphonius) was cloned and sequenced. The total length of the mitochondrial genome is 16,646 bp with an accession number KY228987. Thirty-seven genes are identified in total, including 13 protein-coding genes, 22 transfer RNA (tRNA) genes, 2 ribosomal RNA (rRNA) genes and a putative D-loop region. Among these genes, 9 are encoded on the light strand, while others are encoded on the heavy strand. The overall base composition of mitogenome is 28.39% for A, 16.14% for G, 26.52% for T, 28.96% for C, respectively, with a slight higher A+T content (54.91%). The phylogeny analysis based on 18 COI amino acid sequences suggested that S. niphonius and the other two species from Scomberomorus (Scombridae) formed a cluster apart from the one comprising other genus from Scombridae. The complete mitogenome may shed light on the future study of genetic mechanism of Scomberomorus niphonius.