Heavy cylindrical body, short rounded snout. Two spineless, equal-sized, small dorsal fins. First dorsal fin slightly closer to pelvic fins than pectorals. Small pectoral fins. No anal fin, no keels on base of caudal fin.
Coloration
Grey to blackish, no conspicuous markings.
Distribution
Western Atlantic: Northern areas and Arctic. Cape Cod to Gulf of Maine and Gulf of St. Lawrence. Greenland, Iceland. Eastern Atlantic: Spitzbergen, Norway, North Sea, France and possibly Portugal. South Atlantic and Antarctic: South Africa, Kerguelen Island.
Biology
Abundant. A littoral and epibenthic species of the continental and insular shelves and the upper slopes found down to at least 1200 m. It may move into shallower water during spring and summer times. Prefered water temperatures range from 0.6 to 12° C.
Diet
Fishes, such as herrings, eels, salmon and others.
Size
Average size between 240 cm and 420 cm, total maximum length at least 640 cm. It is the largest shark species in artic and antarctic waters.
Reproduction
Aplacental viviparous (ovoviviparous). Up to about 10 pups per litter.
