On the basis of 417 captures in the Bering Sea and 102 captures in the Pacific waters off the northern Kuril Islands and southeastern Kamchatka the spatial distribution and bathymetry of Pacific sleeper shark Somniosus pacificus are considered. The length frequency and length-weight relation for species considered are given. The diet and feeding habits of Pacific sleeper shark in the western Bering Sea are described. This species was more abundant in the western Bering Sea, where bottom trawl catches were usually represented by 1-10 (maximum 25) specimens and frequency of occurrence made up 42.7%. Pacific sleeper shark was common in Pacific waters off the northern Kuril Islands and southeastern Kamchatka and caught mostly as single specimens with frequency of occurrence in bottom trawl catches about 3.5%. Pacific sleeper shark was occurred on depths from 85 to 717 m (average about 450 m). Most part of fishes were caught in 250-700 m depth range. The catches were represented by sharks with total length from 66 to 300 cm (mean about 132-142 cm). According to Index of Relative Importance (IRI) the red squid Berryteuthis magister was most important dietary component of Pacific sleeper shark in the western Bering Sea. Giant grenadier Albatrossia pectoralis, fishery offal and popeye grenadier Coryphaenoides cinereus were also important in its diet.
A.M. Orlov, Laboratory of Living Resources of Foreign Economic Zones and High Seas, Russian Federal Research Institute of Fisheries and Oceanography (VNIRO) 17 V. Krasnoselskaya, Moscow, 107140, Russia