Mountain Whitefish – Profile | Description | Habitat | Habit | Diet

Mountain Whitefish
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Mountain Whitefish, scientific name Prosopium williamsoni, a member of the Salmonidae family, the mountain whitefish offers a vital winter fishery in sure areas, particularly the place steelhead is absent.

The mountain whitefish (Prosopium williamsoni) is among the most generally distributed salmonid fish of western North America.

It is discovered from the Mackenzie River drainage in Northwest Territories, Canada south via western Canada and the northwestern USA within the Pacific, Hudson Bay, and higher Missouri River basins to the Truckee River drainage in Nevada and Sevier River drainage in Utah.

Mountain Whitefish Identification

Possessing an adipose fin and an axillary course of, the mountain whitefish is long, slender, and almost cylindrical, though not fairly as cylindrical because of the round whitefish.

It is nonetheless among the many species known as “round whitefish” and could be distinguished from the lake whitefish, which is more laterally compressed than is the mountain whitefish.

Silvery total, it’s darkish brownish to olive or greenish to blue-gray above, with scales that usually have darkish borders and ventral and pectoral fins that will have an amber shade in adults.

The smallmouth is barely subterminal, and the snout extends clearly past it. The caudal fin is forked, and there are 74 to 90 scales down the lateral line and 19 to 26-gill rakers.


The body form is superficially much like the cyprinids, though it’s distinguished by having the adipose fin of salmonids. The body is slender and almost cylindrical in cross-part, usually silver with a dusky olive-green shade dorsally.

The quick head has a small mouth beneath the snout. The quick 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 as much as 70 centimeters (28 inches) in size and weight of 2.9 kilograms (6.4 lb).

Mountain Whitefish are light brown on the back and fins and silvery to white on the stomach and sides. Snout and decrease jaw are quick and blunt, with a flap on every nostril.

Mountain whitefish eat insect larvae, bugs, fish eggs, and small fish. Interestingly, mountain whitefish feed most actively through the winter and at night time.

The species spawns from late fall to early winter, normally in stream riffles with gravel substrate. No nests are made, however, eggs are adhesive, and stick with the underside. Eggs hatch within the early spring; no care is given to eggs or younger.

Mountain Whitefish Habitat

It is a fish of mountain streams and lakes, favoring clear chilly water and enormous deep swimming pools of a minimum of a meter’s depth; the Lake Tahoe inhabitants live simply above the underside in deeper water.

Mountain whitefish are backside feeders, stirring up the substrate with pectoral and tail fins to show insect larvae and different invertebrates, together with snails, crayfish, and amphipods.

Their foremost feeding time is within the night, however, they will even take drifting prey through the day. The mountain whitefish regularly feeds within the decrease strata of streams, however, populations might rise to the floor to prey on hatching insects, together with mayflies.

Mountain Whitefish


The mountain whitefish can develop to 22.5 inches and 5 pounds. The all-tackle world file is a 1988 5.5-pound fish from Saskatchewan. The mountain whitefish can dwell for 18 years.

Spawning conduct

Spawning takes place from October via December in shallow, gravelly streams or sometimes in lakes at water temperatures of 42°F or much less. Parents don’t guard the eggs, which incubate over the winter to hatch within the spring.

Food and feeding habits

Mountain whitefish feed totally on benthic organisms like aquatic insect larvae, mollusks, fish, and fish eggs (together with their very own), in addition to on plankton and floor bugs when major meals sources are unavailable.

Other Recommended Reading

Other Names

Rocky mountain whitefish, Williamson’s whitefish, grayling; French: ménomini des Montagnes.


The mountain whitefish is endemic to the lakes and the streams of the northwestern United States and southwestern Canada. It happens inland into Alberta and Wyoming, overlapping the vary of the lake whitefish and barely overlapping that of the spherical whitefish.

Mountain Whitefish Habitat

Generally inhabiting rivers and quick, clear, or silty areas of bigger streams, in addition to lakes, mountain whitefish normally happen in-stream riffles through the summer season and in massive pools within the winter.

They want temperatures of 46° to 52°F and are discovered within the deepwater of some lakes, though in northern lakes they normally maintain no deeper than 30 feet. Learn more about ocean sunfish.

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