Atlantic Wolffish

The Atlantic wolffish (Anarhichas lupus) is a large, elongated, bottom-dwelling fish of the wolffish family, Anarhichadidae, found in cold waters on both sides of the North Atlantic. It is easily recognized by its powerful jaws and strong, blunt teeth adapted for crushing hard-shelled prey such as crabs, sea urchins, and mollusks. Despite its intimidating appearance, it is a solitary, non-aggressive species that shelters in rocky crevices and dens. Populations in parts of its range, particularly the Gulf of Maine, have declined and are subject to conservation concern and protective measures. The species plays a notable ecological role as a predator of hard-shelled invertebrates on cold-water seafloors.

Atlantic wolffish are unmistakable due to their eel-like shape and formidable dentition.

• Body: long, muscular, and scaleless in appearance, tapering toward a small tail
• Coloration: dull olive-grey to bluish-brown, sometimes with faint darker vertical bars
• Head: large, blunt, with powerful jaws and prominent canine-like teeth visible even with the mouth closed
• Fins: single long dorsal fin running nearly the length of the back
• Size: typically 60-120 cm, up to about 1.5 m

It differs from the spotted wolffish by its plain or faintly barred coloration, lacking the dark, well-defined spots that give the spotted wolffish its name.

Atlantic wolffish inhabit cold, rocky or hard-bottomed seafloor habitats on both sides of the North Atlantic, from the Barents Sea and Iceland to the Bay of Biscay in Europe, and from Labrador to the mid-Atlantic United States in North America. They are typically found at depths of 20 to 500 meters, often occupying dens, crevices, or burrows among boulders and rocky outcrops. The species prefers consistently cold water and is closely tied to structured, complex seafloor habitat, which it uses for shelter, feeding, and reproduction. It rarely strays far from suitable rocky refuge once established in a territory.

Atlantic wolffish are solitary and territorial, typically occupying the same rocky den for extended periods and rarely straying far from shelter. They use their powerful jaws and blunt teeth to crush hard-shelled prey such as crabs, sea urchins, whelks, and mussels, making them important predators controlling invertebrate populations on cold-water seafloors. Unlike most fish, wolffish pairs may exhibit extended courtship and guard their egg masses, which are laid in rocky crevices rather than released freely into open water. This parental investment is unusual among bony fish and contributes to relatively low reproductive output, a factor in the species' vulnerability to population decline in parts of its range.