Phylogenetic position of the cryopelagic codfish genus Arctogadus Drjagin, 1932 based on partial mitochondrial cytochrome b sequences

Abstract.

In order to elucidate the phylogenetic position of the cryopelagic cod genus Arctogadus, gadine phylogenetic relationships were examined using the mitochondrial DNA cytochrome b gene. A segment of 401 base pairs was sequenced from 6 gadine species [Arctogadus borisovi Drjagin, A. glacialis (Peters), Gadiculus argenteus Guichenot, Micromesistius poutassou (Risso), Pollachius pollachius (L.), Pollachius virens (L.)] and from 4 gadiform outgroup species. With additional data from GenBank, a dataset of all 12 gadine genera (19 species) was analysed using parsimony and neighbour-joining. Arctogadus appeared in a terminal clade as sistergenus to Boreogadus and closely related to Gadus and Theragra. The relatively small genetic difference between these four genera indicates a need for taxonomic revision, and possibly that Arctogadus should be synonymised with Boreogadus or Gadus. A difference of only 0–2 base pairs between specimens of A. borisovi and A. glacialis indicates that they are conspecific, with A. borisovi as the junior synonym.