Wolffish - 'Deep Sea Monster' Friendly to Humans

Wolffish have the appearance and face of animals from horror movies, but what few people expect is that they are extremely friendly to humans.

The only thing the Atlantic wolffish (Anarhichas lupus) has in common with wolves is that it has sharp teeth and powerful jaws to help it feed. In fact, its teeth are so prominent that some of them protrude from its mouth, giving it a look that is both terrifying and comical—at least by human standards.

In fact, this fish uses its fearsome teeth to dig into the sediments of the ocean floor to feed and break the hard shells of crabs, sea urchins, clams and other hard-shelled creatures. In addition to its trademark teeth, this wolffish also possesses a rather long body and resembles an eel.

Found on both the west and east coasts of the Atlantic Ocean, this fish is a bottom dweller at depths of around 600 metres and is often found in small nooks and crannies. Its body also produces antifreeze to keep its blood flowing, as it lives in water temperatures ranging from -1 to 11 degrees Celsius.

And that's not the only thing that makes this creature special!

While most fish are "oviparous" (with females releasing thousands of eggs into the water and males competing to fertilize them externally), in this species the female will pair up and fertilize the male internally , meaning they mate in the same way mammals do.

Despite their fearsome appearance, these fish are very affectionate towards humans!

The wolffish is a marine fish in the wolffish family Anarhichadidae, native to the North Atlantic Ocean. The Atlantic wolffish population in United States waters is rapidly depleting, likely due to overfishing and overharvesting, and it is currently a species of concern, according to the National Oceanic and Atmospheric Administration's National Marine Fisheries Service. In addition to their unique appearance, wolffish are known for their natural antifreeze , which they produce to keep their blood moving in their extremely cold habitats.

The Atlantic wolffish was first formally described in 1758 in the 10th edition of Systema Naturae by Carl Linnaeus. When Linnaeus described it, he classified it in the genus Anarhichas, so today A. lupus is the species in that genus. The specific name lupus means "wolf", one of the common names for these fish is "sea wolffish" , this name is given because of the fang-like incisors.

The Atlantic wolffish retains the body shape and general external features of its prehistoric ancestors. The largest recorded specimen was 1.5 meters long and weighed nearly 18 kg. Its body is long, sub-cylindrical in the front and tapering towards the tail. The Atlantic wolffish comes in a variety of colors, most commonly seen as purplish brown, dull olive green, or blue-gray. Its blunt, eel-like body shape allows the fish to swim slowly, undulating from side to side, like an eel.

The distinguishing feature of the Atlantic wolffish, from which it takes its common name, is its enlarged tooth structure . Its teeth distinguish the Atlantic wolffish from all other members of the family Anarhichadidae. Both the lower and upper jaws are equipped with four to six strong, conical, fang-like teeth. Behind the conical teeth in the upper jaw are three rows of crushing teeth.

Atlantic wolffish use their powerful jaws to feed on hard-shelled mollusks, crustaceans and echinoderms. They do not eat other fish. They are known to regularly feed on Buccinum species, blood cockles (Polynices, Chrysodomus and Sipho), sea clams (Mactra), large hermit crabs, sea stars and sea urchins.

According to data compiled by the US National Marine Fisheries Service, since 1983, the catch from US Atlantic fishing vessels per trip has decreased by 95%, reaching 64.7 tons in 2007. In 1950, when NMFS began operations, data showed that 1,098 tons of Atlantic wolffish were caught, valued at $137,008. However, the catch quickly dwindled and by 1990, the catch had dropped to 400 tons, and by 2002, it was down to 154 tons. Currently, Atlantic wolffish is classified as a species of concern by the National Marine Fisheries Service.

There are three reasons for the dramatic decline in wolffish numbers: overfishing, accidental ingestion by fishing nets, and trawling close to the seabed that has affected the fish's habitat. Wolffish are classified as 'overfished' because they are too large and have a long reproductive life; the time it takes for their population to recover after being caught is too long, which is why their numbers have declined so dramatically. Fishing boats no longer catch wolffish, but that doesn't mean they are smart enough to avoid the nets.