A cutthroat eel genus Synaphobranchus (Anguilliformes: Synaphobranchidae) in the Western Pacific Ocean

Abstract

A species of the cutthroat eel genus Synaphobranchus is described based on three specimens collected off the Western Pacific Ocean, in depths of 1,298―1,311 m. The species can be sequenced the mitochondrial cytochrome c oxidase subunit 1 (COI) and 16S ribosomal RNA (16S rRNA) genes of two deep-sea fish specimens from the Western Pacific Ocean and molecular phylogenetic relationship analysis was performed using maximum likelihood (ML) method. The molecular phylogenetic tree confirmed two deep sea fish species are deeply nested within Synaphobranchus eels. In particular, these species were clustered together with a bootstrap value of 100% between Synaphobranchus affinis and Synaphobranchus brevidorsalis, suggesting that these species are congeneric species, respectively. This study is the first report of species identification of Synaphobranchus affinis and Synaphobranchus brevidorsalis from the Western Pacific Ocean based on partial COI and 16S rRNA genes.