Circumglobal: In tropical and temperate waters. Western Atlantic: North Carolina to Florida (USA) and northern Gulf of Mexico to northern Argentina. Eastern Atlantic: Iceland and Norway to Namibia, including the Mediterranean. Indian Ocean: Madagascar, Mozambique, and South Africa. Western Pacific: eastern Japan to New Zealand and Hawaii. Eastern Pacific: Aleutian Islands, Alaska to Baja California, Mexico; also Chile.

A heavily-bodied, broad-headed sixgill shark, mouth ventral with 6 rows of lower, bladelike, comb-shaped teeth on each side. Snout broadly rounded, body fusiform. Anal fin smaller than dorsal fin. Brown or grey above, paler below, with a light stripe along side . Fins with white edges. Live specimens with fluorescent green eyes.

Depth range reported at 0m-2000m. A deepwater species of the outer continental and insular shelves and upper slopes. Near bottom, occasionally pelagic, adults usually below 91 m. Juveniles may be found close inshore . Found on the bottom by day, moving to the surface at night to feed, and where it may take longlines set for other species. Depth distribution related to growth and temperature, with juveniles having most shallow records and from colder, poleward regions.