Northern Wolffish

The Northern Wolffish (Anarhichas denticulatus) is a large, deep-water member of the wolffish family, Anarhichadidae, found in cold waters of the North Atlantic and Arctic Ocean, including the Barents Sea, Greenland, and the eastern coast of Canada. It is the largest of the wolffish species and typically occupies deeper, colder water than its relatives, the Atlantic wolffish and spotted wolffish. Northern Wolffish has an elongated, powerful body and strong dentition adapted for crushing hard-shelled invertebrate prey. Due to population declines linked to historical bycatch in deep-water trawl fisheries, it has been assessed as a species of conservation concern in parts of its range, including listing under Canadian species-at-risk frameworks.

Identify the Northern Wolffish by:

• Long, robust, eel-like body reaching up to about 1.5-1.8 m
• Uniform grey to bluish-brown coloration, without the strong blotching or bars seen in Atlantic or spotted wolffish
• Large, blunt head with powerful jaws
• Prominent, protruding canine-like teeth visible even with the mouth closed
• Long, continuous dorsal fin running most of the length of the back
• No pelvic fins

Its plainer, unmarked coloration is the main feature separating it from the Atlantic wolffish, which shows dark vertical bars, and the spotted wolffish, which has dark rounded blotches.

Northern Wolffish inhabits cold, deep waters of the North Atlantic and Arctic Ocean, including the Barents Sea, waters around Greenland and Iceland, and the continental slope off eastern Canada. It typically occurs at greater depths than other wolffish species, ranging from roughly 100 m to over 1500 m, often near the seabed on soft mud or muddy-sand bottoms of the outer continental shelf and slope. It is adapted to near-freezing water temperatures typical of Arctic and sub-Arctic deep-water environments and generally avoids shallow coastal habitats favored by the closely related Atlantic wolffish.

Northern Wolffish is a solitary, bottom-associated predator that uses its powerful jaws and strong teeth to feed on hard-shelled invertebrates such as sea urchins, crabs, and mollusks, as well as fish. Unlike its shallower-water relatives, it does not typically pair up in a den, instead ranging more widely over deep, soft-bottom habitat. It is a slow-growing, late-maturing species, life-history traits that make its populations slow to recover from depletion. Spawning behavior is less well documented than in other wolffish, though eggs are believed to be demersal. As a deep-water predator on hard-shelled invertebrates, Northern Wolffish helps regulate benthic invertebrate communities on the outer shelf and slope.