Abstract:
Features of spatial and vertical distributions of two species of anadromous parasitic lampreys, Arctic lamprey Lethenteron camtschaticum and Pacific lamprey Enthosphenus tridentatus, in the North Pacific Ocean are considered in a comparative perspective. It is shown that the first species is most abundant in the northwestern Pacific (Sea of Japan and Sea of Okhotsk), while second species - in the northeastern Pacific (west coast of USA and Canada). Both species reach high abundance in the Bering Sea, however prefer different biotopes. Arctic lamprey inhabits mostly upper 100-m layer, while Pacific lamprey occupies water column with depths less than 200 m and near-bottom layers shallower 500 m. Based on the features of spatial and vertical distributions, it might be assumed that the hosts of the former species are mainly Pacific salmons Oncrorhynchus spp., while those of the latter species - various demersal fishes such as walleye pollock Theragra chalcogramma, Pacific cod Gadus macrocephalus, Greenland halibut Reinhardtius hippoglossoides, etc.
