Although WolfFish are found mostly in the North Atlantic Ocean they are commonly referred to as Atlantic WolfFish as their habitat extends to the eastern and western coasts of the Atlantic. Found from as far north as Nunavut, a Canadian territory towards Greenland and Nova Scotia to Cape Cod, the densest populations of WolfFish are along the Great South Channel.
Also referred to as Atlantic Catfish, Devil Fish, Ocean Catfish, Seawolf, Wolf Eel and some others, another distinguishable genetic feature is the WolfFish’s ability to keep the blood flowing freely by means of the natural anti-freeze produced in their bodies! The WolfFish’s natural prey comprises green crabs and sea urchins which, if left unchecked, can destroy prime marine habitats. The large presence of WolfFish in the oceans is a target indicator of the health of several other ocean bottom-dwellers like Cod, for instance.
The wolffish gets its name from the very prominent fang-like teeth placed at the front of its jaws, giving it a wolf-like appearance and an almost sci-fi feel; 4 to 6 conical teeth line the upper and lower jaws with rows of crushing molars and serrated teeth all along the interior of its mouth up to the throat. This helps it to feed easily on clams, crustaceans, echinoderms and mollusks as the powerful teeth help it to crunch and break the shells easily. In addition, starfish and sea urchins which are ocean bottom dwellers also form part of its diet. They rarely hunt other fish.
Behavior and Habitat
WolfFish are solitary creatures and not territorial; a large rocky underwater area may be home to several of them. Rarely moving away from their usual habitat, they are known as ‘stationary fish’. Although their massive mouth and prominent teeth give them a fearful appearance, WolfFish are generally shy creatures and are not known to attack humans. However, if handled, they will snap their teeth in defense and can cause serious injuries. They usually hunt for prey at dusk and in the night, preferring to hide within cracks in crevices in rocky underwater areas at depths of over 400 ft. Some are known to dwell at depths of 2000 ft in the Pacific Ocean habitats. Ocean bottoms are the most preferred locations because they provide ample nooks and caves for hiding and dwelling. As mentioned earlier, they are adapted to living in colder waters, sometimes as low as -1°C or -2°C because of the ‘natural anti-freeze’.
The uniqueness of WolfFish species extends to their reproductive methods. Unlike many other marine species, they are relatively late to mature and are not ready to breed until they are about 6 to 8 years old. Autumn is the breeding season. The eggs are internally fertilized by the female WolfFish, a rare occurrence in marine species, and laid on the seabed. The eggs may take up to few weeks or months to hatch, and sometimes up to four months for the hatchlings to become independent during which time the male stays close to them.
The two other prominent WolfFish species are found in British waters, namely (i) Spotted WolfFish, also commonly known as the Spotted Catfish and (ii) Northern WolfFish, commonly referred to as the Arctic WolfFish. Other names for the Arctic WolfFish are the Blue Catfish and the Bull-Head WolfFish. These too have similar distribution patterns as well as feeding and breeding patterns in the oceans like the Atlantic WolfFish and are known to reach lengths of up to 5 feet weighing over 60 pounds.
The Atlantic WolfFish has a rather unique appearance for a fish, bearing some semblance to certain catfish; unlike many other fish species, the WolfFish has an evenly shaped dorsal fin that stretches from the back of its head up to its tail.
Distinguishing the different types of WolfFish is fairly easy and there are a number of ways. The most important common feature that runs through the species is the even dorsal fin that runs the entire length of the top of the body. The absence of pectoral fins gives the fish an eel-like appearance; it also helps it move with an undulating pattern like an eel, a throwback reference to the ‘Wolf Eel’ nomenclature!
- Atlantic WolfFish have flanks carrying vertical bars or stripes and can vary in color from bluish gray to olive green and even purplish brown
- Spotted WolfFish, as the name suggests, have a uniformly spotted appearance
- Northern or Arctic WolfFish have uniform color and texture; the body pattern may be marbled or speckled.
The first two have slimmer bodies when compared to the Northern WolfFish which has an almost bloated body; the extra fat body may be a natural evolution process to keep warm in the freezing waters of the extreme north.
Fishing and conservation
Held in relative esteem as food, fresh as well as preserved, WolfFish enjoy both privileged status in marketability being known as ‘Scotch Halibut’ and ‘Scarborough Woof’ in Britain, and is the popular half of the more common dish “fish n chips”. Icelanders call the fish ‘Steinbitur’ which means ‘stone biter’.
They are also highly prized for the liver oil, equated in status to Cod Liver Oil.
Learning that the WolfFish species has suffered significant decline in numbers is not surprising; so is the case with many marine species which have been over-harvested or become products of by-catch and taken to near extinction. Recreational fishing has also decimated their numbers.
Currently classified as a ‘species of concern’, the WolfFish is included in the list of species that are facing threats of survival but where insufficient data makes it impossible to determine exact status. This was the case in 2007-2008. Since then, however, the Conservation Law Foundation has petitioned marine service agencies to protect WolfFish numbers throughout the northwest Atlantic waters along the United States and Canadian coastlines by designating habitats as ‘critical’ to prevent commercial and recreational fishing. In addition, educational programs for local fishermen on ‘catch and release protocols’ and prohibition on possession of WolfFish are ongoing.
Notwithstanding these preventive measures, the Atlantic WolfFish was in 2014 classified as an endangered species in the International Union for Conservation of Nature (IUCN) Red List.
Myth or Mutant
WolfFish are also fished in recreational fishing, giving rise to many myths about the size of the fish caught. Recently, a specimen of the Atlantic WolfFish was fished off the Hokkaido coast in Japan measuring nearly 2.5 meters in length when the average fish length is only about 1.25 meters. Speculation gave rise to the belief that the fish size was a ‘mutant fallout’ of the Fukushima Nuclear Disaster in 2011 which spilled huge amounts of radiation in the ocean. Scientists however are skeptical and unless more numbers are found for possible research and studies, no conclusions can be made.