Spotted wolffish
Encyclopedia
The spotted wolffish is a large marine fish of the Anarhichadidae
family. Other common names include leopardfish and spotted catfish. It is classified as a threatened species
, at risk of extinction
.
The bottom-dwelling spotted wolffish is found across the North Atlantic from north of Russia
to the Scotian Shelf, off Nova Scotia
. The population declined by about 90 per cent from the late 1970s through the early 1990s, particularly in the northern part of its range.
prominent canine-like teeth in the front of both jaws; a heavy head with a blunt, rounded snout; small eyes; a long, stout body with no pelvic fins; a long dorsal fin
extending to the base of caudal; flexible spiny rays; a small, slightly rounded caudal fin; rounded pectoral fins; firm musculature; colours variable from pale olive to deep brown with upper parts sprinkled with irregularly shaped blackish-brown spots; maximum length to over 1.8 m and weight to 23 kg.
(SARA) and was afforded protection under the SARA as of June 2004.
According to the 2001 COSEWIC assessment of this species, it has not been given international protection status. As of May 2008, it is not listed or categorized on the IUCN Red List
.
and on both sides of the North Atlantic Ocean from Labrador
to the Barents Sea
. Its northern limit in Canada is Baffin Bay
, although its presence is rare. In the Western North Atlantic, it is found off east and west Greenland
, on the Labrador Shelf and Grand Banks
and less commonly on the Scotian Shelf.
and Northern wolffish
(Barents Sea
). Fish become mature at seven years of age or older and can live to 21 years. The species does not form large schools and migrations are local and limited.
s, seaweeds and fish have also been reported in the gut contents of the Spotted Wolffish.
and habitat alteration have played a role in the observed declines in wolffish abundance. In Canadian waters, this fish species is not targeted by the fishing industry, however, by-catch mortality by offshore trawlers and long-liners is considered a threat. In addition, activities that disturb the ocean bottom, such as trawling
, may damage spawning habitat.
(A. denticulatus) and Atlantic wolffish (A. lupus) by its dark spots.
Anarhichadidae
The wolffish are a family, Anarhichadidae, of perciform fish. They are native to cold waters of the northern Atlantic and Pacific Oceans, where they live on the continental shelf and slope, to depths of about . They are bottom-feeders, eating hard-shelled invertebrates such as clams, echinoderms...
family. Other common names include leopardfish and spotted catfish. It is classified as a threatened species
Threatened species
Threatened species are any speciesg animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future.The World Conservation Union is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories,...
, at risk of extinction
Extinction
In biology and ecology, extinction is the end of an organism or of a group of organisms , normally a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point...
.
The bottom-dwelling spotted wolffish is found across the North Atlantic from north of Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...
to the Scotian Shelf, off Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...
. The population declined by about 90 per cent from the late 1970s through the early 1990s, particularly in the northern part of its range.
General description
They have the following characteristics:prominent canine-like teeth in the front of both jaws; a heavy head with a blunt, rounded snout; small eyes; a long, stout body with no pelvic fins; a long dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
extending to the base of caudal; flexible spiny rays; a small, slightly rounded caudal fin; rounded pectoral fins; firm musculature; colours variable from pale olive to deep brown with upper parts sprinkled with irregularly shaped blackish-brown spots; maximum length to over 1.8 m and weight to 23 kg.
Conservation status
This species has been identified as threatened by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). It is listed under the Canadian federal Species at Risk ActSpecies at Risk Act
The Species at Risk Act is a piece of Canadian federal legislation which became law in Canada on December 12, 2002. It is designed to meet one of Canada's key commitments under the International Convention on Biological Diversity. The goal of the Act is to protect endangered or threatened...
(SARA) and was afforded protection under the SARA as of June 2004.
According to the 2001 COSEWIC assessment of this species, it has not been given international protection status. As of May 2008, it is not listed or categorized on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
.
Distribution
Spotted wolffish occur in the Arctic OceanArctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
and on both sides of the North Atlantic Ocean from Labrador
Labrador
Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...
to the Barents Sea
Barents Sea
The Barents Sea is a marginal sea of the Arctic Ocean, located north of Norway and Russia. Known in the Middle Ages as the Murman Sea, the sea takes its current name from the Dutch navigator Willem Barents...
. Its northern limit in Canada is Baffin Bay
Baffin Bay
Baffin Bay , located between Baffin Island and the southwest coast of Greenland, is a marginal sea of the North Atlantic Ocean. It is connected to the Atlantic via Davis Strait and the Labrador Sea...
, although its presence is rare. In the Western North Atlantic, it is found off east and west Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
, on the Labrador Shelf and Grand Banks
Grand Banks
The Grand Banks of Newfoundland are a group of underwater plateaus southeast of Newfoundland on the North American continental shelf. These areas are relatively shallow, ranging from in depth. The cold Labrador Current mixes with the warm waters of the Gulf Stream here.The mixing of these waters...
and less commonly on the Scotian Shelf.
Habitat and life history
This species is found offshore in cold, deep water, usually below 5°C (41°F) and between 50-800 m (160-2600 ft) in depth but as shallow as 25 m (80 ft) in Canadian Arctic populations. They prefer a coarse sand and sand/shell hash bottom with rocky areas nearby for shelter and nest building. Spawning occurs in summer to late fall/early winter. As many as 54,600 large eggs (up to 6 mm {0.25 in} in diameter) are laid in deep water in clusters on the sea floor and are guarded primarily by males. Growth rate is slower for this species than for the AtlanticSeawolf (fish)
The Atlantic wolffish , also known as the Seawolf, Atlantic catfish, ocean catfish, wolf eel , or sea cat, is a marine fish, the largest of the wolffish family Anarhichadidae. They are commonly sighted throughout Asia...
and Northern wolffish
Northern wolffish
The northern wolffish , or rock turbot, is a large marine fish of the Anarhichadidae family. Other common names include the Bull-headed Catfish, Blue Catfish, Broad-headed Catfish, Jelly Wolffish, and the Arctic Wolffish...
(Barents Sea
Barents Sea
The Barents Sea is a marginal sea of the Arctic Ocean, located north of Norway and Russia. Known in the Middle Ages as the Murman Sea, the sea takes its current name from the Dutch navigator Willem Barents...
). Fish become mature at seven years of age or older and can live to 21 years. The species does not form large schools and migrations are local and limited.
Diet
The diet of this fish consists primarily of hard-shelled invertebrates found on the bottom, such as crustaceans and mollusks. Echinoderms, tube wormTube worm
A tube worm is a worm-like sessile invertebrate that anchors its tail to an underwater surface and secretes around its body a mineral tube, into which it can withdraw its entire body.Tube worms are found among the following taxa:...
s, seaweeds and fish have also been reported in the gut contents of the Spotted Wolffish.
Threats
It is believed that overfishingOverfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
and habitat alteration have played a role in the observed declines in wolffish abundance. In Canadian waters, this fish species is not targeted by the fishing industry, however, by-catch mortality by offshore trawlers and long-liners is considered a threat. In addition, activities that disturb the ocean bottom, such as trawling
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net that is used for trawling is called a trawl....
, may damage spawning habitat.
Similar species
The spotted wolffish can be distinguished from the NorthernNorthern wolffish
The northern wolffish , or rock turbot, is a large marine fish of the Anarhichadidae family. Other common names include the Bull-headed Catfish, Blue Catfish, Broad-headed Catfish, Jelly Wolffish, and the Arctic Wolffish...
(A. denticulatus) and Atlantic wolffish (A. lupus) by its dark spots.