The results of the investigations of spatial and vertical distribution of Pacific sleeper shark Somnio sus pacificus in the North Pacific Ocean conducted for many years are presented. In addition, the size distri bution and features of biology of the species are studied. The largest abundance of the species is registered in the Bering Sea, western Gulf of Alaska, eastern Aleutian Islands, and Pacific waters of northern Kuril Islands and southeastern Kamchatka. The species is the most abundant near the bottom at the depth from 200 to 700 m and in the pelagic waters at a depth of 100-200 m. The average depths of the catches of Pacific sleeper shark substantially change over the year reaching minimum values in June and maximum values in December. Ver tical daily migrations (to the water column at night and to the bottom during the day) are registered. The catches are represented by fish 26-352 cm in length, and sharks 100-200 cm in length prevail. The males are noticeably smaller than the females. In general, condition of the fishes decreases and feeding intensity increases with growth. Food composition substantially changes with the increase of body length: consump tion of squids decreases and consumption of crustaceans, fishes, and fishery wastes increases. The food com position is slightly different in the females and males.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.