Complete Mitochondrial DNA Genomes of Deep-Sea Eels Synaphobranchus brevidorsalis and S. affinis and New Record of S. brevidorsalis from the East Mariana Basin

Abstract

In this study, we document the first recorded range extension of the genus Synaphobranchus from the East Mariana Basin in the Western Pacific Ocean. We sequenced the complete mitochondrial (mt) genome of two deep-sea eels (Synaphobranchus brevidorsalis and S. affinis) collected in the East Mariana Basin in the Western Pacific Ocean. The complete mt genomes of S. brevidorsalis and S. affinis were 16,686 bp and 16,677 bp in length, respectively, and consisted of 13 protein-coding genes, 22 tRNA genes, and two rRNA genes. Molecular phylogenetic analysis of the two deep-sea eel species was performed, based on the mt cytochrome c oxidase subunit I (COI) gene using the maximum likelihood method. The molecular phylogenetic tree demonstrated that S. brevidorsalis and S. affinis were congeneric species of S. brevidorsalis and S. affinis reported in previous studies with bootstrap values of 100% and 100%, respectively. This is the first report on the complete mt genomes of S. brevidorsalis and S. affinis collected in the East Mariana Basin in the Western Pacific Ocean. Overall, our study highlights the potential of molecular approaches in identifying species diversity and distribution in the Western Pacific Ocean.