Molecular identity of the Antarctic heteronemertean Parborlasia corrugata (Nemertea: Pilidiophora) from Lützow-Holm Bay

The Antarctic heteronemertean Parborlasia corrugata (McIntosh, 1876) (originally Lineus corrugatus) shows a circumpolar distribution in the Southern Ocean, putatively with high dispersal capacity of the planktonic larva. From the eastern coast of Lützow-Holm Bay near Syowa Station (69°00′S, 39°35′E), several records of heteronemerteans have been made under the name of Lineus corrugatus. However, they have never been explicitly identified by molecular data. In the present study, we determined a partial sequence of the mitochondrial cytochrome c oxidase subunit I (COI) gene for 11 specimens of P. corrugata collected from depths of 17–27 m under sea ice near Syowa Station. A haplotype-network analysis along with other COI sequences from 66 individuals collected at different places in the Antarctic and sub-Antarctic islands, available at public databases, resulted in that all the 11 specimens from Lützow-Holm Bay possessed either of two major haplotypes detected in previous studies. It reflects the effective dispersal of the species between the localities including Lützow-Holm Bay.