Complete mitochondrial genomes and phylogenetic analysis of three species of Indo-Pacific freshwater gobies, Stiphodon (Gobiiformes,Oxudercidae).

Stiphodon is a genus of gobioid fishes found primarily in freshwater streams on islands throughout the Indo-Pacific region. It is the most speciose genus of Sicydiinae, with more than three dozen named species. Complete mitochondrial genome (mtDNA) sequences were determined for three species, namely Stapledon atropurpureus, Stapledon elegans, and Stapledon semoni. Maximum likelihood and Bayes inference inferences from 13 protein-coding genes (11,433 bp) or the COXI gene (1,551 bp) alone were made on these three together with four mitogenomes previously available. S. percnopterygionus and S. tuivi formed an outgroup to the other five Stiphodon species, meanwhile Stapledon atropurpureus and S. semoni were recovered as sister species. The ratios of the non-synonymous to the synonymous ubstitution rates for all PCGs were in the range 0\ (Ka/Ks) \1, which suggests they have been subject to purifying selection.