Brown Trout - Salmo trutta
The brown trout belongs to a different genus than our native trout species. They evolved in Europe and western Asia and were introduced to North America in 1883 and to Montana in 1889 in the Madison River. Today brown trout are found throughout most of Montana except the northwest and parts of the east. Generally, they prefer lower gradient, larger streams than cutthroat and rainbow, and they also do well in many reservoirs. Brown trout were widely stocked in the first half of this century, but today most come from natural reproduction. Brown trout are great competitors and generally are more tolerant of dewatering and other environmental disturbances than our other trout species. The state record is 29 pounds, and large fish are not at all uncommon, although 12-20 inches is the usual size range of adults. Brown trout spawn in gravel redds like our native trout but their spawning season is in the fall. This gives them a distinct advantage in some habitats since their spawning and incubation period lies outside the irrigation season. Brown trout are more predaceous than rainbow or cutthroat. Large fish often feed at night on other fish as well as crayfish and other invertebrates.
May lack red and orange spots. Black spots may be irregularly shaped or round. Spots with halos on gill covers are a clue that trout is a brown trout.
Observations in Montana Natural Heritage Program Database
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May move upstream some distance or into tributary to spawn.
Valley portions of larger rivers where gradients are low and summer temperatures range from 60-70 degrees F. Also reservoirs and lakes at similar elevation with suitable spawning trib. (Brown 1971, Holton 1981).
Feeds largely on underwater aquatic insects. Also uses many other small organisms available and large individuals eat many small fish (Brown 1971).
Habitat requirements similar to brook trout, but brown trout can remain active and thriving at slightly higher temperatures (Scott and Crossman 1973).
Sexually mature usually 3 years but sometimes 2,4, and 5 years. Spawns Oct.-Dec. Eggs laid in redd and hatch the following Spring. Febr.-April under natural conditions. Hatch in about 50 days at 50 degrees F. (Brown 1971).
- Literature Cited AboveLegend: View Online Publication
- Brown, C.J.D. 1971. Fishes of Montana. Montana State University, Bozeman, MT. 207 pp.
- Holton, G.D. 1981. Identification of Montana's most common game and sport fishes. Montana Outdoors reprint.
- Scott, W.B. and E.J. Crossman. 1973. Freshwater fishes of Canada. Fisheries Research Board of Canada, Bulletin 184. 966 pp.
- Additional ReferencesLegend: View Online Publication
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- Alvord, W. 1953. A study of scales from known-age trout. M.Sc. Thesis. Bozeman, MT: Montana State University. 31 p.
- Avery, E.L. 1969. Effects of domestic sewage on aquatic insects and salmonids of the East Gallatin River, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 23 p.
- Bahn, L. 2007. An assessment of losses of native fish to irrigation diversions on selected tributaries of the Bitterroot River, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 118 p.
- Belford, D.A. 1986. Abilities of trout to swim through highway culverts. M.Sc. Thesis. Bozeman, MT: Montana State University. 67 p.
- Bishop, C.G. 1953. Age, growth, and condition of trout in Prickley Pear Creek, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 22 p.
- Boussu, M.F. 1953. Relationship between trout populations and cover on a small stream. M.Sc. Thesis. Bozeman, MT: Montana State University. 26 p.
- Burford, D.D. 2005. An assessment of culverts of fish passage barriers in a Montana drainage using a multi-tiered approach. M.Sc. Thesis. Bozeman, MT: Montana State University. 50 p.
- Carty, D.G. 1985. Potential impacts of altering discharge pattern from Hauser Dam, Missouri River, on young-of-the-year brown and rainbow trout. M.Sc. Thesis. Bozeman, MT: Montana State University. 84 p.
- Clancey, T.P. 1983. Effects of renovation on the Sacajawea Park Lagoon system in Livingston, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 54 p.
- Clothier, W.D. 1952. Fish loss and movement in irrigation diversions from the West Gallatin River, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 32 p.
- Connor, W.P. 1988. Effects of gas supersaturated water on juvenile brown and rainbow trout. M.Sc. Thesis. Bozeman, MT: Montana State University. 96 p.
- Elser, A.A. 1967. Fish population of a trout stream in relation to major habitat zones and channel alterations. M.Sc. Thesis. Bozeman, MT: Montana State University. 27 p.
- Fox, A.C. 1961. Parasite incidence in relation to size and condition of trout from two Montana lakes. M.Sc. Thesis. Bozeman, MT: Montana State University. 16 p.
- Fredenberg, W.A. 1980. The fishery for fall-running rainbow trout in the Missouri River near Townsend, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 62 p.
- Fry, J.P. 1960. The food of rainbow trout, brown trout and brook trout fry and fingerlings from five southwesternMontana streams. M.Sc. Thesis. Bozeman, MT: Montana State University. 37 p.
- Gunderson, D.R. 1966. Stream morphology and fish populations in relation to floodplain use. M.Sc. Thesis. Bozeman, MT: Montana State University. 21 p.
- Holton, G.D. 1952. A trout population study on a small creek in Gallatin County, Montana. M.Sc. Thesis. Bozeman, MT: Montana State University. 46 p.
- Javorsky, L.D. 1984. The trout fishery on a reach of the upper Yellowstone River, Montana, during 1982. M.Sc. Thesis. Bozeman, MT: Montana State University. 45 p.
- Kathrein, J.W. 1950. A partial fisheries survey of the Missouri River between Holter Dam and Cascade, Montana, with special emphasis on growth rate of trout and suckers. M.Sc. Thesis. Bozeman, MT: Montana State University. 27 p.
- Kozakiewicz, V.J. 1979. The trout fishery of the lower Big Hole River, Montana, during 1977 and 1978. M.Sc. Thesis. Bozeman, MT: Montana State University. 74 p.
- Lere, M.E. 1982. The long term effectiveness of three types of stream improvement structures installed in Montana streams. M.Sc. Thesis. Bozeman, MT: Montana State University. 99 p.
- Zackheim, K. 1973. Exhibit H: Wildlife Study. In Ash Grove Cement Co. files.
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