Pacific sleeper shark

The Pacific sleeper shark (*Somniosus pacificus*) is a large deep-water shark in the sleeper shark family, Somniosidae.

The Pacific sleeper shark (*Somniosus pacificus*) is a large deep-water shark in the sleeper shark family, Somniosidae. It lives mainly in the North Pacific Ocean and is also recorded from other Pacific and Antarctic waters. The species is slow-growing and is listed as Near Threatened by the IUCN, and occurs along the Pacific coast of North America, including waters off British Columbia.

Taxonomy and naming

The Pacific sleeper shark is a member of the sleeper shark family Somniosidae and is scientifically named *Somniosus pacificus*. It is one of several large deep-sea sharks grouped in the order Squaliformes.

Distribution and habitat

This species is mainly found in the North Pacific, including waters off Japan and western North America, and has also been documented farther south and in Antarctic waters. It inhabits continental shelves and slopes and may range from shallow coastal zones to deep offshore waters, occurring at depths exceeding 2,000 m.

Size and biology

The Pacific sleeper shark is a large, slow-moving shark, with published lengths reaching about 4.4 m (14 ft). It is considered one of the world's largest predatory sharks and is adapted to cold, deep marine environments.

Conservation

The species is assessed as Near Threatened by the IUCN. Slow growth and exposure to fishing bycatch are major concerns for its population status, making it vulnerable to overexploitation.