The lake trout (''Salvelinus namaycush'') is a freshwater

char Char may refer to: People * Char Fontane, American actress * Char Margolis, American spiritualist * René Char (1907–1988), French poet *The Char family of Colombia: ** Fuad Char, Colombian senator ** Alejandro Char Chaljub, mayor of Barranquill ...

living mainly in

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s in northern

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and th ...

. Other names for it include mackinaw, namaycush, lake char (or charr), touladi, togue, and grey trout. In

Lake Superior Lake Superior in central North America is the largest freshwater lake in the world by surface areaThe Caspian Sea is the largest lake, but is saline, not freshwater. and the third-largest by volume, holding 10% of the world's surface fresh wa ...

, it can also be variously known as siscowet, paperbelly and lean. The lake trout is prized both as a

game fish Game fish, sport fish or quarry refer to popular fish pursued by recreational anglers, and can be freshwater or saltwater fish. Game fish can be eaten after being caught, or released after capture. Some game fish are also targeted commercial ...

and as a food fish. Those caught with dark coloration may be called ''mud hens''.

Taxonomy

It is the only member of the subgenus ''Cristovomer'', which is more derived than the subgenus '' Baione'' (the most basal clade of ''Salvelinus'', containing the

brook trout The brook trout (''Salvelinus fontinalis'') is a species of freshwater fish in the char genus ''Salvelinus'' of the salmon family Salmonidae. It is native to Eastern North America in the United States and Canada, but has been introduced elsewhere ...

(''S. fontinalis'') and silver trout (''S. agasizii'')) but still basal to the other members of ''Salvelinus''.

Range

From a

zoogeographical Zoogeography is the branch of the science of biogeography that is concerned with geographic distribution (present and past) of animal species. As a multifaceted field of study, zoogeography incorporates methods of molecular biology, genetics, mor ...

perspective, lake trout have a relatively narrow distribution. They are native only to the northern parts of

, principally

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by to ...

, but also

Alaska Alaska ( ; russian: Аляска, Alyaska; ale, Alax̂sxax̂; ; ems, Alas'kaaq; Yup'ik: ''Alaskaq''; tli, Anáaski) is a state located in the Western United States on the northwest extremity of North America. A semi-exclave of the U ...

and, to some extent, the northeastern

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

. Lake trout have been widely introduced into non-native waters in North America and into many other parts of the world, mainly

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

, but also into

South America South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sou ...

and certain parts of

Asia Asia (, ) is one of the world's most notable geographical regions, which is either considered a continent in its own right or a subcontinent of Eurasia, which shares the continental landmass of Afro-Eurasia with Africa. Asia covers an are ...

. Although lake trout were introduced into

Yellowstone National Park Yellowstone National Park is an American national park located in the western United States, largely in the northwest corner of Wyoming and extending into Montana and Idaho. It was established by the 42nd U.S. Congress with the Yellowst ...

Shoshone The Shoshone or Shoshoni ( or ) are a Native American tribe with four large cultural/linguistic divisions: * Eastern Shoshone: Wyoming * Northern Shoshone: southern Idaho * Western Shoshone: Nevada, northern Utah * Goshute: western Utah, easte ...

, Lewis and Heart lakes legally in the 1890s, they were illegally or accidentally introduced into

Yellowstone Lake Yellowstone Lake is the largest body of water in Yellowstone National Park. The lake is above sea level and covers with of shoreline. While the average depth of the lake is , its greatest depth is at least . Yellowstone Lake is the largest fre ...

in the 1980s where they are now considered invasive.

Description

Lake trout are the largest of the chars; the record weighed almost (netted) with a length of , and fish are not uncommon. The average length is . The largest caught on a rod and reel according to the IGFA was , caught in Great Bear Lake in 1995 with a length of .

Life history

Lake trout inhabit cold, oxygen-rich waters. They are

pelagic The pelagic zone consists of the water column of the open ocean, and can be further divided into regions by depth (as illustrated on the right). The word ''pelagic'' is derived . The pelagic zone can be thought of as an imaginary cylinder or w ...

during the period of summer stratification in dimictic lakes, often living at depths of . The lake trout is a slow-growing fish, typical of oligotrophic waters. It is also very late to mature. Populations are extremely susceptible to

overfishing Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in t ...

. Many native lake trout populations have been severely damaged through the combined effects of hatchery stocking (planting) and over harvest. Another threat to lake trout is acidification, which can have longterm effects on their populations through both direct harm and reduced prey populations (e.g. ''

Mysis relicta ''Mysis relicta'' is a shrimp-like crustacean in the Mysida order, native to lakes of Northern Europe and to the brackish Baltic Sea. Appearance Mysis is a small, transparent shrimp-like crustacean, of less than 2.5 cm length. It has tw ...

''). There are three

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics ( morphology), but that can successfully interbreed. Not all specie ...

of lake trout. There is the common lake trout (''Salvelinus namaycush namaycush''), the siscowet lake trout (''Salvelinus namaycush siscowet''), and the less common rush lake trout (''Salvelinus namaycush huronicus''). Some lakes do not have

forage fish Forage fish, also called prey fish or bait fish, are small pelagic fish which are preyed on by larger predators for food. Predators include other larger fish, seabirds and marine mammals. Typical ocean forage fish feed near the base of the f ...

during the period of summer stratification. In these lakes, lake trout act as planktivores. Lake trout in planktivorous populations are highly abundant, grow very slowly and mature at relatively small sizes. In those lakes that do contain deep-water forage, lake trout become piscivorous. Piscivorous lake trout grow much more quickly, mature at a larger size and are less abundant. Notwithstanding differences in abundance, the density of

biomass Biomass is plant-based material used as a fuel for heat or electricity production. It can be in the form of wood, wood residues, energy crops, agricultural residues, and waste from industry, farms, and households. Some people use the terms bio ...

of lake trout is fairly consistent in similar lakes, regardless of whether the lake trout populations they contain are planktivorous or piscivorous. In Lake Superior, common lake trout (''S. n. namaycush'') and siscowet lake trout (''S. n. siscowet'') live together. Common lake trout tend to stay in shallower waters, while siscowet lake trout stay in deeper water. Common lake trout (also called "lean" lake trout) are slimmer than the relatively fat siscowet. Siscowet numbers have become greatly depressed over the years due to a combination of the extirpation of some of the fish's deep water coregonine prey and to

overexploitation Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish. The term ap ...

. Siscowet tend to grow extremely large and fat and attracted great commercial interest in the last century. Their populations have rebounded since 1970, with one estimate putting the number in Lake Superior at 100 million. Professor of zoology at the

University of Wisconsin-Madison A university () is an institution of higher (or tertiary) education and research which awards academic degrees in several academic disciplines. Universities typically offer both undergraduate and postgraduate programs. In the United States, th ...

, James Kitchell, credits effective constraint of commercial fisheries and persistent

sea lamprey The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish". Description The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, ...

(Petromyzon marinus) control for the successful recovery of Lake Superior's lake trout. "Looking at what has happened in the lake and the results of computer simulations, it is clear that lamprey control needs to continue if Lake Superior is to keep its lake trout."

Hybrids

Lake trout are known to hybridize in nature with the

; such hybrids, known as " splake", are normally

sterile Sterile or sterility may refer to: *Asepsis Asepsis is the state of being free from disease-causing micro-organisms (such as pathogenic bacteria, viruses, pathogenic fungi, and parasites). There are two categories of asepsis: medical and surgi ...

but self-sustaining populations exist in some lakes. Splake are also artificially propagated in hatcheries, and then stocked into lakes in an effort to provide sport-fishing opportunities.

Commercial fishing

Lake trout were fished commercially in the

Great Lakes The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes in the mid-east region of North America that connect to the Atlantic Ocean via the Saint Lawrence River. There are five lakes ...

until lampreys, overharvest and pollution extirpated or severely reduced the

stocks Stocks are feet restraining devices that were used as a form of corporal punishment and public humiliation. The use of stocks is seen as early as Ancient Greece, where they are described as being in use in Solon's law code. The law describing ...

. Commercial fisheries still exist in some areas of the Great Lakes and smaller lakes in northern

. Commercial fishing by

Ojibwe The Ojibwe, Ojibwa, Chippewa, or Saulteaux are an Anishinaabe people in what is currently southern Canada, the northern Midwestern United States, and Northern Plains. According to the U.S. census, in the United States Ojibwe people are one of ...

for Lake Trout in

is permitted under various

treaties A treaty is a formal, legally binding written agreement between actors in international law. It is usually made by and between sovereign states, but can include international organizations, individuals, business entities, and other legal pers ...

and regulated by the Great Lakes Indian Fish & Wildlife Commission (GLIFWC).

Origin of name

The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bo ...

''namaycush'' derives from ''namekush'', a form of the word used in some inland Southern East Cree communities in referring to this species of fish. Other variations found in East Cree are ''kûkamâs ', ''kûkamâw'' and ''kûkamesh''. Similar cognate words are found in

: ''namegos'' = "lake trout"; ''namegoshens'' = "rainbow trout", literally meaning "little lake trout".

Popular culture

Geneva Geneva ( ; french: Genève ) frp, Genèva ; german: link=no, Genf ; it, Ginevra ; rm, Genevra is the second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaking part of Switzerland. Situa ...

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

claims the title "Lake Trout Capital of the World," and holds an annual lake trout fishing derby.Lake trout derby, Geneva, NY
Accessed September 29, 2010.

References

External links

Fishbase description of Lake trout
{{Taxonbar, from=Q469946 Lake trout Freshwater fish of the United States Freshwater fish of the Arctic Lake fish of North America Fish of the Great Lakes Lake trout Taxa named by Johann Julius Walbaum