 | It has been suggested that this page be merged into Mountain whitefish. (Discuss) Proposed since April 2022. |
| Kb9854/Mountain whitefish | |
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| 16 inches (41 cm) Mountain whitefish, McKenzie River, Oregon | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Salmoniformes |
| Family: | Salmonidae |
| Genus: | Prosopium |
| Species: | P. williamsoni
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| Binomial name | |
| Prosopium williamsoni (Girard, 1856)
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| Synonyms[1] | |
|
Coregonus williamsoni Girard, 1856 Coregonus oregonius Jordan & Snyder, 1909 Prosopium oregonium (Jordan & Snyder, 1909) | |
The mountain whitefish (Prosopium williamsoni) is one of the most widely distributed salmonid fish of western North America.[2] It is found from the Mackenzie River drainage in Northwest Territories, 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.[3]
The fish is named in honor of Lt. Robert S. Williamson (1825-1882) of the U.S. Army Corps of Topographical Engineers, who was in command of a government survey of the proposed transcontinental railroad routes, during which the type specimen was collected.[4]
Contents
edit1. Description
2. LifeHistory
3. Feeding
4. Ecology
4.1 Range
4.2 Habitat
5. Conservation
6. References
Description
editThe body shape is superficially similar to the cyprinids, 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 scales possess pigmented borders, which are especially defined on the posterior end. Mountain Whitefish possess a forked homocercal tail. 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. Size has been recorded at up to 70 centimeters (28 inches) in length and a weight of 2.9 kilograms (6.4 lb).
Life History
editThe spawning season is from October to early December, when water temperatures are 2–6 °C. Mountain whitefish congregate in large schools on fall spawning runs and seek out areas of coarse gravels or cobbles at depths of at least 75 cm (30 inches), typically in shallow areas of small tributaries or shorelines of lakes. Their non-adhesive eggs are scattered along the substrate. The eggs then develop slowly through the winter (6–10 weeks), hatching in the early spring, generally in March.[5] Mountain whitefish reach reproductive maturity at approximately three years old, females can produce as many as 4,000 eggs annually.[6] Mountain whitefish typically live between 7–9 years in the wild.
Feeding
editMountain Whitefish are demersal feeders,[7] stirring up the substrate with pectoral and tail fins to expose insect larvae and other invertebrates, including snails, 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. Mountain whitefish fry are a common food source for brook trout.[8]
Ecology
editHabitat
editThe mountain whitefish are commonly found in mountain streams and lakes, favoring clear cold water and large deep pools of at least a meter's depth; the Lake Tahoe population lives just above the bottom in deeper water.[9]
Range
editThis 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.[10]
Conservation
editMountain Whitefish have a secure conservation status.[11] In many of the larger intermountain Western rivers, Mountain Whitefish are the only native salmonid. Mountain whitefish typically occur in high abundance, in the Snake River Basin, Idaho, Mountain Whitefish abundance was found to be 1,257/100 m.[12]
References
edit- ^ "Synonyms of Prosopium williamsoni (Girard, 1856)". Fishbase. Retrieved 2014-02-24.
- ^ McHugh, J. L. (1940-02-01). "Food of the Rocky Mountain Whitefish Prosopium williamsoni (Girard)". Journal of the Fisheries Research Board of Canada. 5a (2): 131–137. doi:10.1139/f40-013. ISSN 0015-296X.
- ^ Froese, Rainer. "Prosopium williamsoni (Girard, 1856)". FishBase. Retrieved Retrieved 2010-12-28.
{{cite web}}: Check date values in:|access-date=(help) - ^ "Order SALMONIFORMES". The ETYFish Project. 2016-02-19. Retrieved 2022-04-18.
- ^ Webmaster, David Ratz. "Mountain Whitefish - Montana Field Guide". fieldguide.mt.gov. Retrieved 2022-04-18.
- ^ Boyer, Jan Katherine (January 2016). "SPAWNING AND EARLY LIFE HISTORY OF MOUNTAIN WHITEFISH IN THE MADISON RIVER, MONTANA" (PDF). Montana State University.
{{cite web}}: CS1 maint: url-status (link) - ^ "Mountain Whitefish (Prosopium williamsoni) - Species Profile". nas.er.usgs.gov.
- ^ Ellison, J.P. "Diets of mountain whitefish, Prosopium williamsoni (Girard), and brook trout, Salvelins fontinalis (Mitchell), in the Little Walker River, Mono County, California". California Fish and Game. 66(2): 96–104.
- ^ Moyle, Peter B. (1976-01-01). Inland Fishes of California. University of California Press. ISBN 978-0-520-02975-0.
- ^ Webmaster, David Ratz. "Mountain Whitefish - Montana Field Guide". fieldguide.mt.gov.
- ^ Webmaster, David Ratz. "Mountain Whitefish - Montana Field Guide". fieldguide.mt.gov.
- ^ Paragamian, Vaughn L. (2002-09-01). "Changes in the Species Composition of the Fish Community in a Reach of the Kootenai River, Idaho, after Construction of Libby Dam". Journal of Freshwater Ecology. 17 (3): 375–383. doi:10.1080/02705060.2002.9663911. ISSN 0270-5060.
