Pacific Sleeper Shark

Pacific sleeper sharks (Somniosus pacificus) range from the Chukchi Sea, East Siberian and Beaufort seas, to the Bering Sea and in the Pacific Ocean to Baja California and off Japan including the Okhotsk Sea. Closely related to the Greenland shark (Somniosus microcephalus), it is one of the few sharks found in polar waters year-round. Noted for its lethargic nature, the sleeper shark is a large species generally inhabiting deep water from 780 to 6,562 feet (238-2,000m). At high latitudes and in colder water they may venture into shallow near-shore waters or come to the surface (Eschmeyer et al. 1983, Hart 1973). In lower latitudes they are mostly epibenthic (living upon the sea bed). Sleeper sharks are reported to reach lengths to 25 feet (7.6m), although average length and weight are 12 feet (3.65m) and 700 to 800 pounds (320-365kg) (Castro 1983). Eschmeyer et al. reports that the largest captured Pacific sleeper shark was 14.4 feet (4.4 m). A specimen in Kachemak Bay measured 12.9 feet (3.93m) total length.