Lake whitefish
Encyclopedia
The lake whitefish also called the Sault whitefish or gizzard fish, is a species of freshwater whitefish
from North America. Lake whitefish are found throughout much of Canada
and parts of the northern United States
, including all of the Great Lakes
. A valuable commercial fish, they are also occasionally taken by sport fishermen. Smoked, refrigerated, vacuum-packed lake whitefish fillets are now commonly available in North American grocery stores.
Their colouration is olive-green to blue on the back, with silvery sides. They have a small mouth below a rounded snout, and a deeply forked tail. On average, they reach 17 to 22 inches and weigh 1.5 to 4 pounds. They are found in freshwater lakes where they prefer deep, cool water.
Lake whitefish spawn from September through January in water two to four metres in depth. In northwestern Canada, a large spawning migration enters the Athabasca Delta
in late summer, moving upstream in the Athabasca River
. The longest single movement of a tagged whitefish ever recorded was 388 km (241.1 mi), from Fort McMurray
to the north shore of Lake Athabasca
in Alberta
, Canada.
The lake whitefish is considered Least Concern
on the IUCN Red List
list. However, the distinct stock called Lake Simcoe Whitefish is considered a threatened species
in Canada.
Natural predators include burbot
, lake trout
and northern pike
.
Primarily bottom feeders, lake whitefish eat crustaceans, snails, insects, and other small aquatic organisms.
Since the end of the last glaciation (about 12000 years ago), whitefish have been able to re-colonize many North American lakes. As they invaded those environments, they have also diversified into different populations, such that they are now two main ecotypes recognized within the species: a normal and a dwarf ecotype
. These normal and dwarf ecotypes are mainly differentiated by the benthic and pelagic zone they occupy, respectively. Normal whitefish also grow much bigger and live much longer than the dwarf ecotype.
Many of these populations live in sympatry
, yet are reproductively isolated. The fact that they are young species makes them prime candidate to study the evolutionary forces driving their ecological divergence and reproductive isolation.
Freshwater whitefish
The freshwater whitefish are fish of the subfamily Coregoninae in the salmon family Salmonidae. Along with the freshwater whitefish, the Salmonidae includes the freshwater and anadromous trout and salmon species as well as graylings...
from North America. Lake whitefish are found throughout much 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...
and parts of the northern United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
, including all of 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...
. A valuable commercial fish, they are also occasionally taken by sport fishermen. Smoked, refrigerated, vacuum-packed lake whitefish fillets are now commonly available in North American grocery stores.
Their colouration is olive-green to blue on the back, with silvery sides. They have a small mouth below a rounded snout, and a deeply forked tail. On average, they reach 17 to 22 inches and weigh 1.5 to 4 pounds. They are found in freshwater lakes where they prefer deep, cool water.
Lake whitefish spawn from September through January in water two to four metres in depth. In northwestern Canada, a large spawning migration enters the Athabasca Delta
Peace-Athabasca Delta
The Peace–Athabasca Delta is a large freshwater, inland delta in northeastern Alberta located where the Peace and Athabasca Rivers join the Slave River at the western end of Lake Athabasca.-Conservation :...
in late summer, moving upstream in the Athabasca River
Athabasca River
The Athabasca River originates from the Columbia Glacier of the Columbia Icefield in Jasper National Park in Alberta, Canada...
. The longest single movement of a tagged whitefish ever recorded was 388 km (241.1 mi), from Fort McMurray
Fort McMurray, Alberta
Fort McMurray is an urban service area in the Regional Municipality of Wood Buffalo in Alberta, Canada. It was previously incorporated as a city on September 1, 1980. It became an urban service area when it amalgamated with Improvement District No. 143 on April 1, 1995 to create the Municipality...
to the north shore of Lake Athabasca
Lake Athabasca
Lake Athabasca is located in the northwest corner of Saskatchewan and the northeast corner of Alberta between 58° and 60° N.-History:The name in the Dene language originally referred only to the large delta formed by the confluence the Athabasca River at the southwest corner of the lake...
in Alberta
Alberta
Alberta is a province of Canada. It had an estimated population of 3.7 million in 2010 making it the most populous of Canada's three prairie provinces...
, Canada.
The lake whitefish is considered Least Concern
Least Concern
Least Concern is an IUCN category assigned to extant taxon or lower taxa which have been evaluated but do not qualify for any other category. As such they do not qualify as threatened, Near Threatened, or Conservation Dependent...
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...
list. However, the distinct stock called Lake Simcoe Whitefish is considered 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,...
in Canada.
Natural predators include burbot
Burbot
The burbot is the only gadiform fish inhabiting freshwaters. It is also known as mariah, the lawyer, and eelpout. It is closely related to the marine common ling and the cusk...
, 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 northern pike
Northern Pike
The northern pike , is a species of carnivorous fish of the genus Esox...
.
Primarily bottom feeders, lake whitefish eat crustaceans, snails, insects, and other small aquatic organisms.
Since the end of the last glaciation (about 12000 years ago), whitefish have been able to re-colonize many North American lakes. As they invaded those environments, they have also diversified into different populations, such that they are now two main ecotypes recognized within the species: a normal and a dwarf ecotype
Ecotype
In evolutionary ecology, an ecotype,Greek: οίκος = home and τύπος = type, coined by Göte Turesson in 1922 sometimes called ecospecies, describes a genetically distinct geographic variety, population or race within species , which is adapted to specific environmental conditions.Typically, ecotypes...
. These normal and dwarf ecotypes are mainly differentiated by the benthic and pelagic zone they occupy, respectively. Normal whitefish also grow much bigger and live much longer than the dwarf ecotype.
Many of these populations live in sympatry
Sympatry
In biology, two species or populations are considered sympatric when they exist in the same geographic area and thus regularly encounter one another. An initially-interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation...
, yet are reproductively isolated. The fact that they are young species makes them prime candidate to study the evolutionary forces driving their ecological divergence and reproductive isolation.
External links
- Lake Whitefish, Government of Canada, Department of Fisheries and Oceans
- Lake Whitefish, Government of Alberta
- Lake Whitefish, Minnesota, Dept. of Natural Resources
- Great Lakes Whitefish, Michigan Sea GrantNational Sea Grant College ProgramThe National Sea Grant College Program is a program of the National Oceanic and Atmospheric Administration within the U.S. Department of Commerce...
at Michigan State UniversityMichigan State UniversityMichigan State University is a public research university in East Lansing, Michigan, USA. Founded in 1855, it was the pioneer land-grant institution and served as a model for future land-grant colleges in the United States under the 1862 Morrill Act.MSU pioneered the studies of packaging,...