Mountain whitefish
Encyclopedia
The mountain whitefish is one of the most widely distributed salmonid
fish
of western North America
. It is found from the Mackenzie River
drainage in Northwest Territory
, Canada south through western Canada and the northwestern USA in the Pacific, Hudson Bay and upper Missouri River basins to the Truckee River
drainage in Nevada
and Sevier River
drainage in Utah
.
The body shape is superficially similar to the cyprinid
s, although it is distinguished by having the adipose fin of salmonids. The body is slender and nearly cylindrical in cross section, generally silver with a dusky olive green shade dorsally. The short head has a small mouth underneath the snout
. The short dorsal fin
has 12-13 rays, with 11-13 for the anal fin, 10-12 for the pelvic fins, and 14-18 for the pectoral fins. The tail fin is forked. Size has been recorded at up to 70 centimetres (27.6 in) in length and a weight of 2.9 kilograms (6.4 lb).
It is a fish of mountain streams and lakes, favoring clear cold water and large deep pools of at least a meter depth; the Lake Tahoe
population lives just above the bottom in deeper water. Mountain whitefish are bottom feeders, stirring up the substrate with pectoral and tail fins to expose insect larvae and other invertebrates, including snail
s, crayfish
, and amphipods. Their main feeding time is in the evening, but they will also take drifting prey during the day. The mountain whitefish frequently feeds in the lower strata of streams, but populations may rise to the surface to prey on hatching insects, including mayflies.
The spawning
season is from October to early December, when water temperatures are 2-6 °C. The fish seek out areas of coarse gravels or cobbles at depths of at least 75 cm, and scatter the non-adhesive eggs so that they sink into the interstices. The eggs then develop slowly through the winter (6-10 weeks), hatching in the early spring.
This species occurs throughout the western half of North America, as far north as the Mackenzie River
(Canada) and the drainages of the Hudson Bay
, in the Columbia River
, upper Missouri River
, upper Colorado River
, and so forth.
Although once important in the subsistence fisheries of some Native American
peoples, this species has become less available in modern times, possibly due to overharvesting; detailed surveys had not been conducted. Some sportfishing for mountain whitefish occurs. Anglers commonly capture whitefish with small (size 16 to 22) nymphs such as Pheasant Tail, Hare's Ear, and Disco Midge. The fish will also respond to tiny spinners, streamers, and dry flies.
Salmonidae
Salmonidae is a family of ray-finned fish, the only living family currently placed in the order Salmoniformes. It includes salmon, trout, chars, freshwater whitefishes and graylings...
fish
Fish
Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...
of western 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...
. It is found from the Mackenzie River
Mackenzie River
The Mackenzie River is the largest river system in Canada. It flows through a vast, isolated region of forest and tundra entirely within the country's Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories...
drainage in Northwest Territory
Northwest Territory
The Territory Northwest of the River Ohio, more commonly known as the Northwest Territory, was an organized incorporated territory of the United States that existed from July 13, 1787, until March 1, 1803, when the southeastern portion of the territory was admitted to the Union as the state of Ohio...
, Canada south through western Canada and the northwestern USA in the Pacific, Hudson Bay and upper Missouri River basins to the Truckee River
Truckee River
The Truckee River is a stream in the U.S. states of California and Nevada. The river is about long. Its endorheic drainage basin is about , of which about are in Nevada. The Truckee is the sole outlet of Lake Tahoe and drains part of the high Sierra Nevada, emptying into Pyramid Lake in the Great...
drainage in Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
and Sevier River
Sevier River
The Sevier River , extending , is the longest Utah river entirely in the state and drains an extended chain of mountain farming valleys to the intermittent Sevier Lake...
drainage in Utah
Utah
Utah is a state in the Western United States. It was the 45th state to join the Union, on January 4, 1896. Approximately 80% of Utah's 2,763,885 people live along the Wasatch Front, centering on Salt Lake City. This leaves vast expanses of the state nearly uninhabited, making the population the...
.
The body shape is superficially similar to the cyprinid
Cyprinid
The family Cyprinidae, from the Ancient Greek kyprînos , consists of the carps, the true minnows, and their relatives . Commonly called the carp family or the minnow family, its members are also known as cyprinids...
s, although it is distinguished by having the adipose fin of salmonids. The body is slender and nearly cylindrical in cross section, generally silver with a dusky olive green shade dorsally. The short head has a small mouth underneath the snout
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
. The short dorsal fin
Dorsal fin
A dorsal fin is a fin located on the backs of various unrelated marine and freshwater vertebrates, including most fishes, marine mammals , and the ichthyosaurs...
has 12-13 rays, with 11-13 for the anal fin, 10-12 for the pelvic fins, and 14-18 for the pectoral fins. The tail fin is forked. Size has been recorded at up to 70 centimetres (27.6 in) in length and a weight of 2.9 kilograms (6.4 lb).
It is a fish of mountain streams and lakes, favoring clear cold water and large deep pools of at least a meter depth; the Lake Tahoe
Lake Tahoe
Lake Tahoe is a large freshwater lake in the Sierra Nevada of the United States. At a surface elevation of , it is located along the border between California and Nevada, west of Carson City. Lake Tahoe is the largest alpine lake in North America. Its depth is , making it the USA's second-deepest...
population lives just above the bottom in deeper water. Mountain whitefish are bottom feeders, stirring up the substrate with pectoral and tail fins to expose insect larvae and other invertebrates, including snail
Snail
Snail is a common name applied to most of the members of the molluscan class Gastropoda that have coiled shells in the adult stage. When the word is used in its most general sense, it includes sea snails, land snails and freshwater snails. The word snail without any qualifier is however more often...
s, crayfish
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...
, and amphipods. Their main feeding time is in the evening, but they will also take drifting prey during the day. The mountain whitefish frequently feeds in the lower strata of streams, but populations may rise to the surface to prey on hatching insects, including mayflies.
The spawning
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
season is from October to early December, when water temperatures are 2-6 °C. The fish seek out areas of coarse gravels or cobbles at depths of at least 75 cm, and scatter the non-adhesive eggs so that they sink into the interstices. The eggs then develop slowly through the winter (6-10 weeks), hatching in the early spring.
This species occurs throughout the western half of North America, as far north as the Mackenzie River
Mackenzie River
The Mackenzie River is the largest river system in Canada. It flows through a vast, isolated region of forest and tundra entirely within the country's Northwest Territories, although its many tributaries reach into four other Canadian provinces and territories...
(Canada) and the drainages of the Hudson Bay
Hudson Bay
Hudson Bay , sometimes called Hudson's Bay, is a large body of saltwater in northeastern Canada. It drains a very large area, about , that includes parts of Ontario, Quebec, Saskatchewan, Alberta, most of Manitoba, southeastern Nunavut, as well as parts of North Dakota, South Dakota, Minnesota,...
, in the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
, upper Missouri River
Missouri River
The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...
, upper Colorado River
Colorado River
The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...
, and so forth.
Although once important in the subsistence fisheries of some Native American
Indigenous peoples of the Americas
The indigenous peoples of the Americas are the pre-Columbian inhabitants of North and South America, their descendants and other ethnic groups who are identified with those peoples. Indigenous peoples are known in Canada as Aboriginal peoples, and in the United States as Native Americans...
peoples, this species has become less available in modern times, possibly due to overharvesting; detailed surveys had not been conducted. Some sportfishing for mountain whitefish occurs. Anglers commonly capture whitefish with small (size 16 to 22) nymphs such as Pheasant Tail, Hare's Ear, and Disco Midge. The fish will also respond to tiny spinners, streamers, and dry flies.