Lake trout
Overview
Lake trout is a freshwater char
Salvelinus
Salvelinus is a genus of salmonid fish often called char or charr; some species are called "trout". Salvelinus is a member of the Salmoninae subfamily of the Salmonidae family. Charr may be identified by light cream pink or red spots over a darker body. Scales tend to be small, with 115-200 along...

 living mainly in lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s in 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...

. Other names for it include mackinaw, lake char (or charr), touladi, togue, and grey trout. In Lake Superior
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...

, they can also be variously known as siscowet, paperbellies and leans. Lake trout are prized both as game fish
Game fish
Game fish are fish pursued for sport by recreational anglers. They can be freshwater or marine fish. Game fish can be eaten after being caught, though increasingly anglers practise catch and release to improve fish populations. Some game fish are also targeted commercially, particularly...

 and as food fish
Seafood
Seafood is any form of marine life regarded as food by humans. Seafoods include fish, molluscs , crustaceans , echinoderms . Edible sea plants, such as some seaweeds and microalgae, are also seafood, and are widely eaten around the world, especially in Asia...

.
From a zoogeographical
Zoogeography
Zoogeography is the branch of the science of biogeography that is concerned with the geographic distribution of animal species.-External links:*: A course outline and collection of Web resources by Dr. Taylor, UBC...

 perspective, lake trout are quite rare.
Encyclopedia
Lake trout is a freshwater char
Salvelinus
Salvelinus is a genus of salmonid fish often called char or charr; some species are called "trout". Salvelinus is a member of the Salmoninae subfamily of the Salmonidae family. Charr may be identified by light cream pink or red spots over a darker body. Scales tend to be small, with 115-200 along...

 living mainly in lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

s in 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...

. Other names for it include mackinaw, lake char (or charr), touladi, togue, and grey trout. In Lake Superior
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...

, they can also be variously known as siscowet, paperbellies and leans. Lake trout are prized both as game fish
Game fish
Game fish are fish pursued for sport by recreational anglers. They can be freshwater or marine fish. Game fish can be eaten after being caught, though increasingly anglers practise catch and release to improve fish populations. Some game fish are also targeted commercially, particularly...

 and as food fish
Seafood
Seafood is any form of marine life regarded as food by humans. Seafoods include fish, molluscs , crustaceans , echinoderms . Edible sea plants, such as some seaweeds and microalgae, are also seafood, and are widely eaten around the world, especially in Asia...

.

Range

From a zoogeographical
Zoogeography
Zoogeography is the branch of the science of biogeography that is concerned with the geographic distribution of animal species.-External links:*: A course outline and collection of Web resources by Dr. Taylor, UBC...

 perspective, lake trout are quite rare. They are native only to the northern parts of 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...

, principally 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...

 but also Alaska
Alaska
Alaska is the largest state in the United States by area. It is situated in the northwest extremity of the North American continent, with Canada to the east, the Arctic Ocean to the north, and the Pacific Ocean to the west and south, with Russia further west across the Bering Strait...

 and, to some extent, the northeastern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Lake trout have been introduced into many other parts of the world, mainly into Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...

 but also into South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 and certain parts of Asia
Asia
Asia is the world's largest and most populous continent, located primarily in the eastern and northern hemispheres. It covers 8.7% of the Earth's total surface area and with approximately 3.879 billion people, it hosts 60% of the world's current human population...

. In Canada, approximately 25% of the world's lake trout lakes are found in the province of Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

. Even at that, only 1% of Ontario's lakes contain lake trout.

Description

Lake trout are the largest of the charrs, the record weighing almost 46.3 kg (102 lb).

Life history

Lake trout inhabit cold, oxygen-rich waters. They are pelagic
Pelagic zone
Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...

 during the period of summer stratification
Lake stratification
Lake stratification is the separation of lakes into three layers:# Epilimnion - top of the lake.# Metalimnion - middle layer that may change depth throughout the day.# Hypolimnion - the bottom layer....

 in dimictic lake
Dimictic lake
Dimictic lakes are lakes that mix from top to bottom during two mixing periods each year. Dimictic lakes are holomictic, a category which includes all lakes which mix one or more times per year. During winter they are covered by ice...

s, often living at depths of 20–60 m (60–200 ft).

The lake trout is a slow growing fish, typical of oligotroph
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...

ic waters. It is also very late to mature. Populations are extremely susceptible to overexploitation
Overexploitation
Overexploitation, also called overharvesting, refers to harvesting a renewable resource to the point of diminishing returns. Sustained overexploitation can lead to the destruction of the resource...

. Many native lake trout populations have been severely damaged through the combined effects of hatchery stocking (planting) and overharvest.

It is generally accepted that there are two basic types of lake trout populations. Some lakes do not have pelagic
Pelagic zone
Any water in a sea or lake that is not close to the bottom or near to the shore can be said to be in the pelagic zone. The word pelagic comes from the Greek πέλαγος or pélagos, which means "open sea". The pelagic zone can be thought of in terms of an imaginary cylinder or water column that goes...

 forage fish
Forage fish
Forage fish, also called prey fish or bait fish, are small 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 food chain on plankton, often by filter feeding...

 during the period of summer stratification. In these lakes, lake trout take on a life history known as planktivory. Lake trout in planktivorous populations are highly abundant, grow very slowly and mature
Sexual maturity
Sexual maturity is the age or stage when an organism can reproduce. It is sometimes considered synonymous with adulthood, though the two are distinct...

 at relatively small size. In those lakes that do contain deep water forage, lake trout become piscivorous
Piscivore
A piscivore is a carnivorous animal which eats primarily fish. Piscivory was the diet of early tetrapods , insectivory came next, then in time reptiles added herbivory....

. 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 (ecology)
Biomass, in ecology, is the mass of living biological organisms in a given area or ecosystem at a given time. Biomass can refer to species biomass, which is the mass of one or more species, or to community biomass, which is the mass of all species in the community. It can include microorganisms,...

 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
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...

, three distinct phenotype
Phenotype
A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...

s of lake trout persist, commonly known as "siscowet", "paperbelly" and "lean". The distinct groups operate, to some level at least, under genetic control and are not mere environmental adaptations. Siscowet numbers, especially, have become greatly depressed over the years due to a combination of the extirpation
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...

 of some of the fish's deep water coregonine prey and to overexploitation. Siscowet tend to grow extremely large and fat and attracted great commercial interest in the last century. Siscowet populations have rebounded since 1970, with one estimate putting the number in Lake Superior at 100 million.

Hybrids

Lake trout have been known, very rarely, to hybridize in nature with the brook trout
Brook trout
The brook trout, Salvelinus fontinalis, is a species of fish in the salmon family of order Salmoniformes. In many parts of its range, it is known as the speckled trout or squaretail. A potamodromous population in Lake Superior are known as coaster trout or, simply, as coasters...

, but such hybrids, known as "splake
Splake
The splake is a hybrid of two fish species resulting from the crossing of a male brook trout and a female lake trout...

", are almost invariably reproductively sterile
Infertility
Infertility primarily refers to the biological inability of a person to contribute to conception. Infertility may also refer to the state of a woman who is unable to carry a pregnancy to full term...

. Splake are also artificially propagated in hatcheries and then planted into lakes in an effort to provide sport fishing opportunities.

Commercial fishing

Lake trout were fished commercially
Fishing industry
The fishing industry includes any industry or activity concerned with taking, culturing, processing, preserving, storing, transporting, marketing or selling fish or fish products....

 in 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...

 until lampreys, overharvest
Overfishing
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 pollution extirpated
Local extinction
Local extinction, also known as extirpation, is the condition of a species which ceases to exist in the chosen geographic area of study, though it still exists elsewhere...

 or severely reduced the stocks
Fish stock
Fish stocks are subpopulations of a particular species of fish, for which intrinsic parameters are the only significant factors in determining population dynamics, while extrinsic factors are considered to be insignificant.-The stock concept:All species have geographic limits to their...

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

.

Origin of name

The specific
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 epithet 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[h], kûkamâw and kûkamesh. Similar cognate words are found in Ojibwe
Ojibwe language
Ojibwe , also called Anishinaabemowin, is an indigenous language of the Algonquian language family. Ojibwe is characterized by a series of dialects that have local names and frequently local writing systems...

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

Popular culture

In Baltimore
Baltimore
Baltimore is the largest independent city in the United States and the largest city and cultural center of the US state of Maryland. The city is located in central Maryland along the tidal portion of the Patapsco River, an arm of the Chesapeake Bay. Baltimore is sometimes referred to as Baltimore...

, Maryland
Maryland
Maryland is a U.S. state located in the Mid Atlantic region of the United States, bordering Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware to its east...

, the term "lake trout" is used to refer to a popular fast food
Fast food
Fast food is the term given to food that can be prepared and served very quickly. While any meal with low preparation time can be considered to be fast food, typically the term refers to food sold in a restaurant or store with preheated or precooked ingredients, and served to the customer in a...

 sandwich
Sandwich
A sandwich is a food item, typically consisting of two or more slices of :bread with one or more fillings between them, or one slice of bread with a topping or toppings, commonly called an open sandwich. Sandwiches are a widely popular type of lunch food, typically taken to work or school, or...

 of fried Atlantic whiting.

Geneva
Geneva, New York
Geneva is a city in Ontario and Seneca counties in the U.S. state of New York. The population was 13,617 at the 2000 census. Some claim it is named after the city and canton of Geneva in Switzerland. Others believe the name came from confusion over the letters in the word "Seneca" written in cursive...

, New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

claims the title "Lake Trout Capital of the World," and holds an annual lake trout fishing derby.

External links

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