Anarrhichthys ocellatus
wolf-eel

Wolf-eels are found in the temperate North Pacific in coastal waters from the Sea of Okhotsk and the Sea of Japan to the Aleutian islands and along the western coast of North America to Baja California. (Feeney et al., 2007; Froese, 2008)

Wolf-eels are exclusively marine, found in shallow, cold, coastal waters. They have been found in depths as low as 226 meters, but are generally found in shallow water. They are demersal in their habits, being found almost exclusively in sheltered, rocky, sub-tidal areas or near rocky structures in areas with sandy bottoms. They remain in a rock shelter unless excluded by a larger wolf-eel or octopus. Juvenile stages are pelagic for their first 2 years of life. (Froese, 2008; Sempier, 2003)

Wolf-eels are large, eel-like fish similar in appearance to morays (Muraenidae). They are up to 240 cm in total length and a maximum of 18.4 kg. They have robust heads and large pectoral fins with 18 to 24 rays. The body is long and tubular, tapering to a pointed tail. Wolf-eels have the most elongated morphology of other wolf-fishes (Anarhichadidae), which are mostly only moderately elongate. They have a single, long dorsal fin that stretches the length of their body, tapering to a point at the tail. It has 218 to 250 flexible spines. The anal fin is also long, with 180 to 233 soft rays. There are no pelvic fins. Wolf-eels have a single pair of nostrils, a moderately well-developed lateral line, and no swim bladder. These fish have very robust, caniniform teeth. (Froese, 2008)

Wolf-eel eggs are protected by both parents until they hatch at 91 to 112 days. Juveniles are pelagic, drifting in water currents until they reach 2 years old, at which point they settle in shallow, coastal areas with structures that provide denning sites. (Froese, 2008; Sempier, 2003)

Wolf-eel maximum lifespan is not reported. Age at maturity occurs at 4 to 7 years, suggesting these may be long-lived fish. (Froese, 2008; Sempier, 2003)

Wolf-eels remain in their rock crevices during the day and emerge to forage at night. They roam widely looking for fish and invertebrate prey, but have a great deal of site fidelity - returning to the daytime dens and inhabiting them for long periods of time. Vacated dens are rapidly inhabited by other wolf-eels, though, so they may patrol potential den sites regularly. They seem to be territorial, aggressively defending their den area. Wolf-eels are occasionally caught by hook and line anglers, so there may be some limited daytime activity. (Hulberg and Graber, 1980)

Home Range

Home range sizes are not reported for wolf-eels

There is little information available on communication and perception in wolf-eels. It is likely that the most important modes of perception are vision and use of the lateral line to detect motion and vibrations. (Froese, 2008; Sempier, 2003)

Wolf-eels use their robust jaws and teeth to eat hard-shelled invertebrates, such as crabs up to 114 mm in width, snails, sand dollars, sea urchins, mussels, clams, and abalone, especially Haliotis kamtschatkana. In the Monterey area the dominant food items are slender crabs (Cancer gracilis) and sand dollars (Dendraster excentricus). Wolf-eels occasionally eat fish as well, although they seem best able to capture slow-moving prey. (Emmet and Jamieson, 1988; Froese, 2008; Hulberg and Graber, 1980; Sempier, 2003; Waldron, 1958)

Wolf-eel eggs are eaten by rockfish (Sebastes species) and kelp greenlings (Hexagrammos decagrammus). Wolf-eels aggressively defend their territories. When threatened, they approach the threat with the mouth held open, displaying the teeth. (Sempier, 2003)

Wolf-eels are important predators of marine invertebrates, especially crabs, mollusks, and echinoderms. (Froese, 2008; Hulberg and Graber, 1980; Sempier, 2003)

Wolf-eels have robust jaws and teeth and can inflict a painful bite if disturbed, although they seem to rarely attack unless severely provoked. (Froese, 2008; Hulberg and Graber, 1980)

Wolf-eels are considered good to eat and are taken for food by humans. There are small-scale commercial fisheries that take wolf-eels and they are considered a potential species useful in aquaculture. Wolf-eels are kept in zoos and aquariums, although they are difficult to keep and may be aggressive. (Froese, 2008; Sempier, 2003)

Wolf-eels have not been evaluated by the IUCN red list. Several of their close relatives, species of wolfish (Anarichas), are considered threatened or species of concern by the Canadian Species at Risk program, prompting recent genetic research on this group. In coastal California, reports suggest wolf-eel populations are large, but no systematic survey is reported. (Hulberg and Graber, 1980; Johnstone, Marshall, and Carr, 2007)

The generic name comes from the Greek anarrhichesis, meaning to climb. (Froese, 2008)