Deepwater sculpin
Encyclopedia
The deepwater sculpin is a freshwater
Freshwater
Fresh water is naturally occurring water on the Earth's surface in ice sheets, ice caps, glaciers, bogs, ponds, lakes, rivers and streams, and underground as groundwater in aquifers and underground streams. Fresh water is generally characterized by having low concentrations of dissolved salts and...

 sculpin
Sculpin
A Sculpin is a fish that belongs to the order Scorpaeniformes, suborder Cottoidei and superfamily Cottoidea, that contains 11 families, 149 genera, and 756 species...

 that inhabits the bottoms of cold, deep freshwater lakes of northern North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

. Its distribution ranges from the Great Bear Lake
Great Bear Lake
Great Bear Lake is the largest lake entirely within Canada , the third or fourth largest in North America, and the seventh or eighth largest in the world...

 of Canada
Canada
Canada is a North American country consisting of ten provinces and three territories. Located in the northern part of the continent, it extends from the Atlantic Ocean in the east to the Pacific Ocean in the west, and northward into the Arctic Ocean...

 to the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

. It is a designated at-risk fish species in Canada, protected as a species of Special Concern under Canada's Species at Risk Act.

The deepwater sculpin is generally gray-brown with mottling on its head, back, and sides with a whitish underside. When full-grown, they are usually between 4 and 6 inches (10–15 cm), but they can reach to 9 inches (23 cm). They weigh less than an ounce (<25 g). They are a bottom-feeding species, which makes them vulnerable to a build-up in contaminants in polluted lakes. They were considered extinct in Lake Erie
Lake Erie
Lake Erie is the fourth largest lake of the five Great Lakes in North America, and the tenth largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. It is bounded on the north by the...

 and Lake Ontario
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north and southwest by the Canadian province of Ontario, and on the south by the American state of New York. Ontario, Canada's most populous province, was named for the lake. In the Wyandot language, ontarío means...

, but have recently been rediscovered there. They mostly eat tiny crustaceans and aquatic insects
Aquatic insects
Aquatic insects live some portion of their life cycle in the water. They feed in the same ways as other insects. Some diving insects, such as predatory diving beetles, can hunt for food underwater where land-living insects cannot compete.-Breathing:...

 and are eaten by lake trout
Lake trout
Lake trout is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, lake char , touladi, togue, and grey trout. In Lake Superior, they can also be variously known as siscowet, paperbellies and leans...

 and other predatory fish.

Distribution

The distribution of the Deepwater Sculpin is almost entirely limited to Canada with the exception of the American Great Lakes and a few inland lakes in Michigan, Minnesota and Montana. A September 2007 study by the Waterton Lakes National Park and the University of Lethbridge found that the Deepwater Sculpin is the third most common fish in Upper Waterton Lake in extreme northwestern Montana and Canada.

"In Canada, its distribution is patchy and limited to cold, deep lakes in areas that were formerly glaciated or with proglacial lake connections. This includes the Gatineau region through the Laurentian Great Lakes, Manitoba and Saskatchewan and northward to Great Bear and Great Slave lakes in the Northwest Territories. An isolated population also exists in Waterton Lake, Alberta. Designated at risk (Special Concern) are the Great Lakes-Western St. Lawrence populations, which are found in only 10 lakes in eastern Canada. In Ontario, this fish occurs in lakes Nipigon, Ontario, Superior, Fairbank, Huron and Erie. In Lake Erie, only larvae (young-of-the-year) have been observed. In Quebec, it occurs in Lac des Îles and in Roddick, Thirty-one-Mile and Heney lakes. Populations in Heney Lake and Lac des Îles are in decline or may even no longer exist."

Habitat and Life History

"The Deepwater Sculpin is a bottom-dwelling fish that is found in cold (< 5 °C), well oxygenated, deep lakes. In the Great Lakes, adults usually live between 60 and 150 m in depth. For this reason, not much is known about the biology of this fish. The reproductive cycle is not well understood and the time of spawning is not known. Age of maturity has been estimated at three years for females and two for males. It appears that individuals from the Great Lakes, especially Lake Ontario, are generally larger compared to other populations. The Deepwater Sculpin is also likely preyed upon by deepwater Lake Trout (Salvelinus namaycush)."

Diet

"The diet of Deepwater Sculpin consists largely of the crustaceans Mysis
Mysis diluviana
Mysis diluviana is a mysid crustacean that inhabits freshwater lakes of northern North America.-Appearance:Mysis is a small, transparent shrimp-like crustacean, of less than length...

and Diporeia and chironomid larvae. Zooplankton likely comprise the diet of the larval stage, which is pelagic (open water). Often found to survive on spineless type Manson bugs that frequent the deep water of the cold deep lakes."

Threats

"The Deepwater Sculpin is likely impacted by changes in zooplankton species composition and abundance. For example, a decline in Diporeia spp. in the lower Great Lakes may pose a threat to this fish since it is an important food source. In addition, the enrichment of lakes with nutrients (eutrophication) and the resulting low oxygen levels in bottom waters likely contributed to the decline of the Deepwater Sculpin in Heney Lake and Lac des Îles."

Similar Species

The marine and freshwater forms of the fourhorn sculpin
Fourhorn sculpin
The fourhorn sculpin is a species of fish in the Cottidae family. It is a demersal fish distributed mainly in brackish arctic coastal waters in Canada, Greenland, Russia, and Alaska, and also as a relict in the boreal Baltic Sea...

 (M. quadricornis) are closely related to the deepwater sculpin. However, the marine four-horn sculpin has four horn-like spines on top of the head, which are lacking in the deepwater sculpin. The freshwater fourhorn sculpin is only found in arctic
Arctic
The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...

regions of Canada.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK