E-Fauna BC: Electronic Atlas of the Wildlife of British Columbia

Prosopium williamsoni (Girard, 1856)
Mountain Whitefish; Riverine Mountain Whitefish
Family: Salmonidae
Photo of species

© Ian Gardiner  Email the photographer   (Photo ID #5788)


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Source: Distribution map provided by Don McPhail for E-Fauna BC
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Species Information

Dorsal spines (total): 0; Dorsal soft rays (total): 11 - 15; Anal spines: 0; Anal soft rays: 10 - 13; Vertebrae: 53 - 61. Body slender, elongate, nearly cylindrical in cross section but variable, more compressed laterally than round whitefish. Head short; eye moderate, its diameter less than snout length; snout more or less pointed, compressed laterally, pinched, rounded in lateral view, a single flap of skin present between nostrils. Mouth small, ventral in position, overhung by snout; maxillaries extending posteriorly almost to anterior margin of eye in adults. Teeth small, restricted to a small patch on tongue and on gill rakers in adults, although small teeth may be present on the premaxillaries in young, but absent from jaws, vomer, palatines and pre maxillae in adults. Overall coloration silvery, but light or dark brown or olive on back, becoming silvery in sides and white below. Scales, specially on back, may have pigmented borders. dorsal fin often dusky, pelvic and pectoral fins in adults with amber tint.

Source: FishBase. Page, L.M. and B.M. Burr 1991 A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p.

Biology

Species Biology

Occurs in lakes and fast, clear or silty streams. Feeds mainly on benthic organisms such as aquatic insect larvae, mollusks, fishes, and fish eggs (including their own) but may feed on plankton and surface insects when the need arises (Ref. 1998).

Source: FishBase. Page, L.M. and B.M. Burr 1991 A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p.

Distribution

BC Distribution and Notes

The biology of riverine mountain whitefish is reasonably well known. They have a complex life cycle and make major spawning, over-wintering, and summer feeding migrations. In contrast, the biology of lacustrine populations is poorly known. We do know that there are major differences in body form between riverine and lacustrine populations and, that in Kootenay Lake there are spatially and temporally separate spawning runs. This suggests that in large lakes there may be multiple demes. Additionally, in many interior rivers there are two riverine forms — a normal form and a longnose “pinocchio” form. The two forms differ in foraging behaviour, morphology and there is some evidence of genetic differences. This should be checked out.

Source: Information provided by Don McPhail for E-Fauna BC.
Global Distribution

North America: Mackenzie River drainage in Northwest Territory, Canada south through western Canada and northwestern USA in the Pacific, Hudson Bay and upper Missouri River basins to Truckee River drainage in Nevada and Sevier River drainage in Utah, USA.

Source: FishBase. Page, L.M. and B.M. Burr 1991 A field guide to freshwater fishes of North America north of Mexico. Houghton Mifflin Company, Boston. 432 p.
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Status Information

Origin StatusProvincial StatusBC List
(Red Blue List)
COSEWIC
NativeS5YellowNot Listed
BC Ministry of Environment: BC Species and Ecosystems Explorer--the authoritative source for conservation information in British Columbia.

Additional Range and Status Information Links

Additional Photo Sources

General References


Recommended citation: Author, Date. Page title. In Klinkenberg, Brian. (Editor) 2021. E-Fauna BC: Electronic Atlas of the Fauna of British Columbia [efauna.bc.ca]. Lab for Advanced Spatial Analysis, Department of Geography, University of British Columbia, Vancouver. [Accessed: 2022-08-16 4:15:15 PM]
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