The physical barriers in the meso- and bathypelagic layers of the open ocean are obscure compared with those in terrestrial, coastal, and ocean epipelagic habitats, which has led to the assumption that little genetic structure exists within deep-sea zooplankton

The physical barriers in the meso- and bathypelagic layers of the open ocean are obscure compared with those in terrestrial, coastal, and ocean epipelagic habitats, which has led to the assumption that little genetic structure exists within deep-sea zooplankton

Seven species of two genera of pelagic chaetognaths (Eukrohnia hamata, E. bathypelagica, E. fowleri, Sagitta elegans, S. macrocephala, S. scrippsae. and S. zetsios) were collected at Ocean Station P (50°N, 145°W) from February 1980 to January 1981. The