Common name: Mountain Whitefish
available through www.itis.gov
Identification: Scott and Crossman (1973); Wydoski and Whitney (1979); Sigler and Sigler (1987); Page and Burr (1991).
Size: 57 cm.
Native Range: Mackenzie River drainage (Arctic basin), Northern Territories, south through western Canada and northwestern United States in Pacific, Hudson Bay, and upper Missouri River basins, to Truckee River drainage, Nevada, and Sevier River drainage, Utah (Page and Burr 1991).
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Prosopium williamsoni are found here.
Table last updated 9/29/2023
† Populations may not be currently present.
Ecology: As with many western North American salmonids, Mountain Whitefish generally inhabit clear, cool waters (< 20° C) of high elevation streams, rivers, and lakes (Moyle 2002). Spawning occurs during late fall to early winter (October - December) in shallow areas of small tributaries or shoreline areas of lakes, primarily over gravel, rubble, or cobble bottoms (McAffee 1966; Moyle 2002). Mountain Whitefish are demersal feeders, consuming a range of benthic invertebrates, including insect larva, gastropods, and small crustaceans(McAffee; Ellison 1980; Moyle 2002).
Means of Introduction: Stocked for sportfishing in Colorado and as a game and food fish in Michigan.
Status: Established in Colorado. Extirpated in Michigan.
Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.
References: (click for full references)
Ellison, J.P. 1980. 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.
Emery, L. 1985. Review of fish introduced into the Great Lakes, 1819-1974. Great Lakes Fishery Commission Technical Report, volume 45.
McAffee, W. R. 1966. Mountain whitefish. 299-303 in A. Calhoun, ed. Inland Fisheries Management. California Department of Fish and Game.
Moyle, P.B. 2002. Inland fishes of California. 2nd edition. University of California Press, Berkeley, CA.
Page, L.M. and B.M. Burr. 1991. A field guide to freshwater fishes of North America north of Mexico. The Peterson Guide Series, vol. 42. Houghton Mifflin Company, Boston, MA.
Sigler, W.F., and J.W. Sigler. 1987. Fishes of the Great Basin: a natural history. University of Nevada Press, Reno, NV.
Scott, W.B., and E.J. Crossman. 1973. Freshwater fishes of Canada. Fisheries Research Board of Canada, Bulletin 184. Ottawa.
Wiltzius, W.J. 1985. Fish culture and stocking in Colorado, 1872-1978. Division Report 12. Colorado Division of Wildlife.
Wydoski, R.S., and R.R. Whitney. 1979. Inland fishes of Washington. University of Washington Press, Seattle, WA.
Pam Fuller, and Matt Neilson
Revision Date: 6/29/2023
Peer Review Date: 4/10/2012
Pam Fuller, and Matt Neilson, 2023, Prosopium williamsoni (Girard, 1856): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=924, Revision Date: 6/29/2023, Peer Review Date: 4/10/2012, Access Date: 9/29/2023
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.