The Atlantic wolffish (Anarhichas lupus), also known as the seawolf, Atlantic catfish, ocean catfish, devil fish, wolf eel (the common name for its Pacific relative), woof or sea cat, is a marine fish of the wolffish family Anarhichadidae, native to the North Atlantic Ocean. The numbers of the Atlantic wolffish in US waters are rapidly being depleted, most likely due to overfishing and bycatch, and it is currently a Species of Concern according to the U.S. National Oceanic and Atmospheric Administration's National Marine Fisheries Service.

Apart from their unique appearance, wolffish are distinguished by the natural antifreeze they produce to keep their blood moving fluidly in their very cold habitat, involvement by both the male and female in brood bearing and the large size of their eggs. They are also an important factor in controlling green crab and sea urchin populations, which can become overly disruptive to habitats if left unchecked. Wolffish population success is also an important indicator of the health of other bottom-dweller populations, such as Atlantic cod. When Linnaeus described it he classified it within the monotypic genus Anarhichas so today A. lupus is the type species of that genus. The specific name lupus means "wolf", one of the common names for these fishes is "sea wolf", the name being given because of the canine-like front teeth.

Characteristics

thumb|left|Atlantic wolffish

The Atlantic wolffish has retained the bodily form and general external characteristics of small blennies (Blennioidei). The largest specimen recorded measured long and weighed almost . An even dorsal fin extends the whole length of the back, and a similar fin from the vent to the caudal fin, as in blennies. The pectorals are large and rounded and the pelvic fins are entirely absent. Its obtuse, eel-like body type makes the fish swim slowly, undulating from side to side, like an eel. Both the lower and upper jaws are armed with four to six fang-like, strong, conical teeth. Behind the conical teeth in the upper jaw, there are three rows of crushing teeth. The central row has four pairs of molars and the outer rows house blunted conical teeth. The lower jaw has two rows of molars behind the primary conical teeth. The wolffish's throat is also scattered with serrated teeth.

Atlantic wolffish inhabit both the west and east coasts of the Atlantic. In the west Atlantic, they are present as far north as the Davis Strait, of the Canadian territory of Nunavut, populating the shores of Greenland, Newfoundland, and Nova Scotia, extending as far south as Cape Cod. Although they are seldom seen south of Cape Cod, there have been sightings in New Jersey. The densest populations are in Georges Bank, the Gulf of Maine and the Great South Channel. In the eastern Atlantic, they range from Russia's White Sea and Novaya Zemlya, through the Nordic countries and British Isles, to the Bay of Biscay. A single record was reported in 1958 from the western Mediterranean Sea in the gulf of Genoa, Italy.

Atlantic wolffish are primarily stationary fish, rarely moving from their rocky homes. They are benthic dwellers, living on the hard ocean floor, frequently seen in nooks and small caves. They like cold water, at depths of .

In Iceland and Norway, the Atlantic wolfish is known as "steinbítur" or "steinbit", which translates to "stone biter" in English. This name is derived from the fish's strong jaws and teeth, which are capable of crushing hard-shelled prey such as shellfish and crustaceans.

Diet

thumb|right|[[Skull]]

thumb|Drawing of the jaws of the seawolf from [[1911 Encyclopædia Britannica]]

Atlantic wolffish use their strong jaws to eat hardshell molluscs, crustaceans, and echinoderms. They do not eat other fish. They are known to frequently eat large whelks (Buccinum), cockles (Polynices, Chrysodomus and Sipho), sea clams (Mactra), large hermit crabs, starfish, and sea urchins. They are an important predator of sea urchins and green crabs, whose populations escalate rapidly and can negatively affect the health of a marine system. The eggs are laid on the ocean floor, often in shoal water, sticking together in loose clumps, surrounded by seaweeds and stones. Atlantic wolffish mature relatively late, at age six. In 1950, when the NMFS started collecting their data, of Atlantic wolffish were landed, worth $137,008. In 1970, ; the landings peaked in 1983 at , bringing in $455,291; rapidly depleting again and by 1990 the landings were down to , and by 2002, . The last available data from the NMFS were in 2007 at , worth a total of $100,341. On January 1, 2009 the NMFS announced a positive 90-day finding that the petition was warranted, which triggered the initiation of a status review which will result in a decision on whether to list the species under the ESA. On November 6, 2009, the NMFS issued a finding that the proposed protections were not warranted.

In 2014, HELCOM classified the Atlantic wolffish population in the Baltic Sea as endangered on the IUCN Red List scale.

References

Footnotes

  • NMFS Species of Concern: Atlantic Wolffish
  • CLF Fact Sheet on Atlantic Wolffish
  • Distribution, biology and management
  • General information on the Atlantic wolffish