Many fish get their common names because of their striking resemblance to the species they're being compared to. For example, the parrotfish and the zebrafish got their names because they resemble zebras and parrots, respectively. Today we're going to talk about another fish whose common name comes from its resemblance to a wolf. Yes, we're going to talk about the pufferfish.
The wolf fish is also known as the Atlantic catfish, ocean catfish, and devil fish . Its scientific name is Anarhichas lupus , and it belongs to the Anarichadidae family. Want to learn all about this fish?
Taxonomy and common names
Anarhichas lupus belongs to the Kingdom Animalia , Phylum Chordata , Class Actinopterygii , Order Perciformes , and Family Anarichadidae . Other related species are recognized within the genus Anarhichas (such as A. denticulatus , A. minor , and A. orientalis ), all colloquially known as wolffish , although here we focus on the Atlantic wolffish.
In addition to its more popular names, this fish may appear in literature and listings with other names: northern dog , wolf eel , sea cat or sea wolf (not to be confused with the mammal), and even with historical synonyms in its taxonomy such as Anarhichas strigosus , Anarhichas vomerinus or Anarhichas lupus marisalbi , terms used in old works or specific regions.
Wolffish characteristics
Fish belonging to this family have historically been responsible for controlling populations of green crabs and sea urchins . This makes this species highly valuable, as it helps us control certain species that are more harmful to the habitat if left unchecked. Furthermore, the wolf fish acts as an indicator of the health of the seabed , since its presence decreases significantly in highly degraded or polluted areas.
The wolffish has a robust and unique appearance that distinguishes it from the majority de peces temperate-cold coastal areas. Its teeth resemble those of a wolf: It has four to six prominent, conical, and powerful front teeth, the same in both jaws, followed by a central row with pairs of molars and outer rows with blunt, conical teeth. This combination, together with a bony plate on the palate, allows you to crush very hard shells.
In the lower part of the jaw, it also has two rows of molars and, behind them, conical teeth, while the throat is covered with small, scattered teeth that help to hold shelled prey and prevent them from escaping.
As for its body, it is elongated and subcylindrical at the front, with a smooth, slippery texture. Its scales are rudimentary and embedded , almost hidden in the skin, giving it a rubbery feel. The dorsal fin is continuous and very long , extending almost the entire length of the back, and the anal fin is also extensive. The pectoral fins are large and rounded , acting as paddles for maneuvering on rocky bottoms, while it lacks pelvic fins , a very characteristic feature of the group.
The largest recorded wolffish exceeded 1,5 m in length and weighed around 18 kg . Its color varies between purple, brown, dull olive green, and bluish-gray , with possible bands or faint mottling, providing excellent camouflage among rocks, algae, and mixed bottoms. Its body resembles that of an eel, and therefore it swims slowly , relying on its powerful jaws and ambush tactics rather than rapid chases.
Habitat
It is distributed on both sides of the North Atlantic and reaches Arctic waters . In the northeastern Atlantic, it is common along the coasts of Scandinavia, Iceland, and Greenland , as well as in the Barents Sea, the Norwegian Sea, and the Baltic Sea , occasionally reaching the northern British Isles and even the Cantabrian coast and some areas of northern Iberia. In the northwestern Atlantic, it occupies the arc from the Canadian Arctic to Nova Scotia, Newfoundland, and southern Labrador , reaching Cape Cod , and is rarely sighted in New Jersey . It is also reported in the Davis Strait, near the Canadian territory of Nunavut.
Because they are not fast swimmers, they are stationary fish . They tend to stay close to their "homes" in crevices, caves, and rocky crevices . They are found in the benthic zone (seafloor) and can be seen in small cavities and nooks formed by rocks and natural reefs.
They live at depths between 20 and 500 meters , preferring rocky or mixed bottoms with pebbles, coarse sand, and shells. They like cold waters , with temperatures that typically range between -1 and 11°C . To withstand these conditions, their bodies produce antifreeze glycoproteins that prevent blood crystallization, a key adaptation for their survival at high latitudes.
This species is sensitive to sudden changes in habitat: where the bottom is in good condition (less suspended sediment, less pollution and preserved rock structure), it is usually more abundant; when the bottom is degraded by bottom drag or pollution, its presence decreases.
Food
The wolffish uses its powerful jaws to eat mollusks (clams, cockles, large bivalves), crustaceans (crabs), and echinoderms (sea urchins) . Its conical front teeth grasp and crack, while the lateral molars and bony palate plate crush shells and carapaces . In this way, it gains access to the protein- and mineral-rich meat inside.
It rarely feeds on other fish , and when it does, it is usually opportunistic. Its usual diet consists of shelled invertebrates, thanks to its highly specialized chewing apparatus, which, according to observations, is even capable of biting through hard materials such as soft wood in marine structures.
It has excellent ambush hunting skills and powerful jaws; therefore, it effectively controls populations of sea urchins and green crabs . In clear, well-oxygenated waters with complex benthic habitats, the abundance of this fish tends to increase, helping to maintain the balance of bottom communities and promoting kelp forests and seagrass meadows by reducing herbivory pressure from sea urchins.
Reproduction
The wolffish's method of egg fertilization differs from that of other fish, such as the ocean sunfish. Instead of releasing eggs into the open ocean for external fertilization, fertilization is internal , and the male remains in the nest protecting the eggs for an extended period, typically several months . This protection includes using his fins to ventilate the eggs and actively defending them against predators.
The eggs laid by the female are between 5,5 and 6 mm in diameter , among the largest known in demersal marine fish. They are opaque yellow and are laid on the ocean floor in shallow, sheltered areas, forming clusters or gelatinous masses that adhere to rocks and algae. They can also be found attached to loose clumps surrounded by algae and pebbles.
To reproduce, wolf fish need to reach maturity after several years . From that point on, they can form stable pairs during the breeding season, showing marked fidelity to their nest and territory. When the pups are large and strong enough to be independent, the male leaves the nest , and the juveniles begin their benthic life among crevices and algae.
This reproductive strategy of low fecundity and high parental investment contrasts with that of many pelagic fish and explains their sensitivity to habitat disturbances: the destruction of nests by trawling gear or increased sedimentation can drastically reduce the reproductive success of a local population.
State of conservation
Wolffish populations have declined locally in parts of the Atlantic due to overfishing and bycatch (especially from bottom trawling ). These fishing methods, in addition to removing individuals, destroy refuges and nests where this species shelters and reproduces, tearing away rocks, sponges, and structural algae. Recreational fishing, although less impactful than commercial fishing, also affects areas where the species is caught incidentally.
At the global assessment level, different institutions offer complementary approaches. The IUCN has listed the Atlantic wolffish as Data Deficient (insufficient information to accurately assess a global risk), while in the western North Atlantic, NOAA has designated it as a Species of Concern in some listings, due to the combination of fishing pressures and degradation of benthic habitats. In areas where management has improved and bottom closures , bycatch reduction devices, and marine protected areas have been established , signs of recovery are observed.
Beyond fishing pressure, factors such as warming waters and changes in benthic community structure could alter their distribution and reproductive success. Given their ecological role and biology (relatively slow growth, late maturity, and parental care), it is advisable to prioritize precautionary measures : improving the selectivity of fishing gear, limiting trawling in sensitive habitats, protecting spawning areas, and promoting responsible consumption where appropriate.
Due to its diet, the wolffish is a keystone predator in cold benthic communities. By reducing sea urchin and certain crab populations, it promotes kelp forests and living substrates that provide shelter for a multitude of invertebrates and fish. In the absence of this pressure, sea urchins can overgraze algae, impoverishing the underwater landscape and reducing biodiversity.
Although its appearance is imposing, its flesh is white, firm, and flavorful , increasingly prized in the regional cuisine of North Atlantic countries. Steaks, broths, and grilled dishes benefit from its compact texture. However, this growing culinary interest must be accompanied by sustainability criteria : opting for certified catches, avoiding undersized specimens, and respecting closed seasons and minimum sizes are necessary measures to avoid further pressure on the species and its habitat.
As for its maintenance in public aquariums, it is only viable in specialized cold-water setups with large volumes, precise cooling, rocky substrates, and abundant hiding places. It is not recommended for home aquariums due to its size, thermal requirements, and specialized diet.
In marine science and outreach, the wolf fish is frequently used as a flagship species to explain the link between fishing gear, benthic habitat structure and the functioning of temperate-cold ecosystems, as well as its fascinating adaptation through antifreeze proteins.
How to recognize it at a glance? Large head with prominent jaws and thick lips, conical front teeth very visible when the mouth is open, elongated body with a large, continuous dorsal fin , broad pectoral fins , and a complete absence of pelvic fins. Coloration is brown, greenish, or bluish-gray, often with dull stripes on the flanks. It rests on the bottom and usually avoids swimming in the water column.
With all of the above, the wolffish reveals itself as an unmistakable fish of the cold Atlantic: a specialist in crushing shells , a sentinel of the seabed's condition , and a key component of benthic balance . Conserving its refuges and fishing responsibly are the two most effective ways to ensure it continues to fulfill its ecological role while also maintaining its cultural and gastronomic value in the regions where it forms part of the maritime tradition.