The complete mitochondrial genome sequence and gene organization of Amblychaeturichthys hexanema (Gobiidae: Amblychaeturichthys) with phylogenetic consideration

Abstract

We sequenced and characterized the complete mitochondrial genome of Amblychaeturichthys hexanema and uncovered its molecular phylogenetic relationship. This genome was 18 642 bp in size, and contained 37 classic genes, including 13 protein-coding genes, 22 transfer RNA genes and 2 ribosomal RNA genes. The gene organization and nucleotide composition were the same with those found in most other Gobiidae fishes. In contrast, gene NADH 6 was obviously larger than the same gene identified from other Gobiidae species. Two big repeat regions were detected on both sides of D-loop region. The A + T content (71.2%) of D-loop region was higher than any other region in this genome. Among 37 genes, 28 were encoded by the heavy strand, while nine were encoded by the light strand. The total nucleotide composition of this genome was 28.6% for A, 15.8% for G, 27.2% for C, and 28.3% for T, with a high A + T content of 56.9%. Phylogeny analysis of 22 fish species within Gobioidei showed that A. hexanema and Chaeturichthys stigmatias first formed a single cluster, then they together with other 17 species grouped a big branch. This work should be helpful for the studies on population genetic diversity and molecular evolution of Gobiidae fish species.