Characterization of complete mitochondrial genome of fives tripe wrasse (Thalassoma quinquevittatum, Lay & Bennett, 1839) and phylogenetic analysis

To further supplement the genome-level features in related species, T. quinquevittatum complete mtDNA was firstly sequenced and de novo assembled by next-generation sequencing. The full-length mtDNA of T. quinquevittatum was a 16,896 bp fragment, which was atypical of Labridae, with 2 ribosomal RNA (rRNA) genes, 13 protein-coding genes (PCGs), 23 transfer RNA (tRNA) genes, and a major non-coding control region (D-loop region). Additionally, the mtDNA of T. quinquevittatum exhibited characteristics of A (27.1%), T (29.3%), G (17.8%), and C (25.8%) with a high A + T content (56.4%). Furthermore, the analysis of the average Ka/Ks in the 13 PCGs of three Labridae species indicated a strong purifying selection within this group. Additionally, the phylogenetic analysis based on 13 concatenated PCGs nucleotide and amino acid datasets, showed high value support for the following sister clade among the four genera (T. quinquevittatum, Halichoeres trimaculatus, Halichoeres melanurus, Parajulis poecilepterus). The complete mtDNA of the T. quinquevittatum provided important information for the study in population genetics and evolutionary theory.