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 Barranquilla ...

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 the Car ...

. 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 Food is any substance consumed by an organism for nutritional support. Food is usually of plant, animal, or fungal origin, and contains essential nutrients, such as carbohydrates, fats, proteins, vitamins, or minerals. The substance is ing ...

. 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 :''The name "silver trout" is also sometimes used for rainbow trout.'' The silver trout (''Salvelinus agassizii'') is an extinct char species or variety that inhabited a few waters in New Hampshire prior to 1939, when a biological survey conducte ...

(''S. agasizii'')) but still basal to the other members of ''Salvelinus''.

Range

From a zoogeographical 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 tot ...

, 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.S., ...

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 primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

. 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 southe ...

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 area ...

. 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 Yellowston ...

's Shoshone,

Lewis Lewis may refer to: Names * Lewis (given name), including a list of people with the given name * Lewis (surname), including a list of people with the surname Music * Lewis (musician), Canadian singer * "Lewis (Mistreated)", a song by Radiohead ...

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 Great Bear Lake ( den, Sahtú; french: Grand lac de l'Ours) is a lake in the boreal forest of Canada. It is the largest lake entirely in Canada (Lake Superior and Lake Huron are larger but straddle the Canada–US border), the fourth-largest ...

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 lake A dimictic lake is a body of freshwater whose difference in temperature between surface and bottom layers becomes negligible twice per year, allowing all strata of the lake's water to circulate vertically. All dimictic lakes are also considered ho ...

s, often living at depths of . The lake trout is a slow-growing fish, typical of

oligotroph An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates o ...

ic waters. It is also very late to mature. Populations are extremely susceptible to overfishing. Many native lake trout populations have been severely damaged through the combined effects of

hatchery A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish, poultry or even turtles. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled cond ...

stocking (planting) and over harvest. Another threat to lake trout is

acidification Acidification may refer to: * Ocean acidification, decrease in the pH of the Earth's oceans * Freshwater acidification, atmospheric depositions and soil leaching of SOx and NOx * Soil acidification, buildup of hydrogen cations, which reduces the ...

, 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 ...

''). 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 species ...

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 foo ...

during the period of summer stratification. In these lakes, lake trout act as

planktivores A planktivore is an aquatic organism that feeds on planktonic food, including zooplankton and phytoplankton. Planktivorous organisms encompass a range of some of the planet's smallest to largest multicellular animals in both the present day and ...

. 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 A piscivore () is a carnivorous animal that eats primarily fish. The name ''piscivore'' is derived . Piscivore is equivalent to the Greek-derived word ichthyophage, both of which mean "fish eater". Fish were the diet of early tetrapod evoluti ...

. 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 bi ...

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 Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

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 app ...

. 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

hybrid Hybrid may refer to: Science * Hybrid (biology), an offspring resulting from cross-breeding ** Hybrid grape, grape varieties produced by cross-breeding two ''Vitis'' species ** Hybridity, the property of a hybrid plant which is a union of two dif ...

ize in nature with the

; such hybrids, known as "

splake The splake or slake (''Salvelinus namaycush x Salvelinus fontinalis'') is a hybrid of two fish species resulting from the crossing of a male brook trout (''Salvelinus fontinalis'') and a female lake trout (''Salvelinus namaycush''). The name it ...

", are normally sterile 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 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 app ...

and pollution

extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...

or severely reduced the stocks. 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 The Great Lakes Indian Fish & Wildlife Commission (GLIFWC) is an intertribal, co-management agency committed to the implementation of off-reservation treaty rights on behalf of its eleven-member Ojibwa tribes. Formed in 1984 and exercising authorit ...

(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, bot ...

''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 List of cities in Switzerland, second-most populous city in Switzerland (after Zürich) and the most populous city of Romandy, the French-speaki ...

, New York 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 The lake trout (''Salvelinus namaycush'') is a freshwater char living mainly in lakes in northern North America. Other names for it include mackinaw, namaycush, lake char (or charr), touladi, togue, and grey trout. In Lake Superior, it can also ...

Freshwater fish of the United States Freshwater fish of the Arctic Lake fish of North America Fish of the Great Lakes

Taxa named by Johann Julius Walbaum