Description
Synonymy- Recently (~1992) , the Rainbow Trout, long known as Salmo gairdneri, was synonomized with an earlier described trout from Siberia and the Far East (formerly S. mykiss). All Pacific trouts (excluding the Charrs of the genus Salvelinus) have been also recently moved into the Pacific salmon genus Oncorhynchus (Jenkins and Burkhead 1993).
Other Taxonomic Groupings - Other subspecies include 'Golden Trouts' of California (Jenkins and Burkhead 1993). Fish stocked in VA (and probably MD and PA) are of uncertain heritage, most originated from the McCloud River of the Sacramento drainage, and could be the coastal O. m. iridaeus, the interior 'redband' O. m. gairdneri, or a hybrid of the two. Anadromous 'steelhead' populations have evolved from both subspecies (Jenkins and Burkhead 1993).
Taxonomy
| Kingdom | Phylum | Class | Order | Family | Genus |
|---|---|---|---|---|---|
| Animalia | Chordata | Osteichthyes | Salmoniformes | Salmonidae | Oncorhynchus |
Synonyms
Invasion History
Chesapeake Bay Status
| First Record | Population | Range | Introduction | Residency | Source Region | Native Region | Vectors |
|---|---|---|---|---|---|---|---|
| 1880 | Established | Stable | Introduced | Boundary Resident | North America | Asia-North America | Fisheries(Fisheries Intentional) |
History of Spread
Oncorhynchus mykiss (Rainbow Trout) is native to the Pacific Slope of North America, from Kuskokwim AK; to Rio Santo Domingo (Baja California), and from the upper MacKenzie River (Arctic Basin) Alberta and British Columbia (Page and Burr 1991). It is also native to northeast Asia as well (Jenkins and Burkhead 1993). Oncorhynchus mykiss have both permanent freshwater populations and anadromous stocks, known as 'Steelhead' (Scott and Crossman 1973). 'Steelhead' range through the cooler coastal waters of the northern Pacific. Oncorhynchus mykiss were widely introduced in eastern North America by the United States Fish Commission and state agencies, and are now stocked annually by many state agencies. Freshwater populations are established in the northeast, from NH to MN, and Ontario, south in the Appalachians to AL and GA, in Rockies from WY to NM (Lee et al. 1980). Stream-dwelling fish and migratory Steelheads are now abundant in the Great Lakes (Mills et al. 1993), but in the Hudson River basin, as on most of the East Coast, O. mykiss populations appear to largely confined to streams, and only stray into the estuary (Smith and Lake 1990; Mills et al. 1997). In the St. Lawrence River estuary, a high frequency of captures suggests that anadromous populations are established there (Dumont et al. 1988). Steelhead were stocked on the New England coast in the 1970s and 80s, but have not established sea-running populations, to our knowledge. Extensive Steelhead-rearing aquaculture operations in fresh and salt water in Maine and Atlantic Canada (Bridger et al. 2001) do have a potential for escapes and future establishment.
Oncorhynchus mykiss has been introduced to non-native drainages in all 50 U.S. states (Fuller et al. 1999) and worldwide in cold waters, including high mountain regions in tropical and subtropical Africa, Asia, and South America (Lee et al. 1980; Lever 1996).
In the Chesapeake drainage, widespread introductions by United States Fish Commission started in 1880 , with 23,000 fish stocked that year in MD drainages Smiley 1884a), and subsequently in VA (Jenkins and Burkhead 1993) and PA (Bean 1893). Reproduction is very limited, and most populations in the watershed are dependent on annual stocking (Jenkins and Burkhead 1993). Oncorhynchus mykiss are only occasional strays in the Chesapeake, but a few fish have been collected in the Lower Bay (Musick 1972a) at salinities up to 18.8 ppt (Schwartz 1965).
James River - Oncorhynchus mykiss is established in the mountains only, but two adults in the estuary (near Surry VA) may have been hatchery escapes (Jenkins and Burkhead 1993).
Potomac River - In 1880, O. mykiss was stocked at many locations in MD tributaries (Smiley 1884a). Breeding populations occur in a few mountain tributaries of the Shenandoah, and in some MD tributaries (Jenkins and Burkhead 1993; Lee et al. 1976).
Patuxent River- Oncorhynchus mykiss was stocked stocked in upper tributaries before 1884, but is confined to the uppermost parts of the drainage (Smiley 1884a; Mansueti 1950).
Susquehanna River- Oncorhynchus mykiss was stocked in ponds in Port Deposit MD in 1880 (Smiley 1884a), and was widely stocked in PA tributaries before 1893 (Bean 1893). Oncorhynchus mykiss occur frequently in the Susquehanna below Conowingo Dam (Pavol and Davis 1982; McKeown 1984; Susquehanna Anadromous Fish Restoration Comittee 1993-1998).
Upper Bay and Tributaries- Oncorhynchus mykiss was stocked in the Patapsco, Gunpowder, Bush, and other tributaries (Smiley 1884a). It is an occasional stray in tidal waters: 'reaches lower reaches of MD tributaries, rare in upper Chesapeake Bay, winter' (Musick 1972a).
Eastern Shore Tributaries - In DE, stockings of O. mykiss continue, but no reproduction occurs (Raasch and Altemus 1991). They are stocked in MD tributaries also, and do not survive the summer (McInich 1995 personal communication).
An anadomous 'Steelhead' was caught at Ocean City MD in the early 1990s, and probably derived from New England stockings (McInich 1995 personal communication).
History References - Bean 1893; Bridger et al. 2001; Courtenay et al. 1984; Fuller et al. 1999; Jenkins and Burkhead 1993; Lee 1976; Lee et al. 1980; Lever 1996; Mansueti 1950; McKeown 1984; Musick 1972a; Pavol and Davis 1982; Raasch and Altemus 1991; Schwartz 1964; Smiley 1884a; Susquehanna Anadromous Fish Restoration Comittee 1993-1998
Invasion Comments
Ecology
Environmental Tolerances
| For Survival | For Reproduction | |||
|---|---|---|---|---|
| Minimum | Maximum | Minimum | Maximum | |
| Temperature (ºC) | 0.0 | 28.0 | 5.0 | 13.0 |
| Salinity (‰) | 0.0 | 35.0 | 0.0 | 0.0 |
| Oxygen | ||||
| pH | ||||
| Salinity Range | fresh-eu |
Age and Growth
| Male | Female | |
|---|---|---|
| Minimum Adult Size (mm) | ||
| Typical Adult Size (mm) | ||
| Maximum Adult Size (mm) | ||
| Maximum Longevity (yrs) | ||
| Typical Longevity (yrs |
Reproduction
| Start | Peak | End | |
|---|---|---|---|
| Reproductive Season | |||
| Typical Number of Young Per Reproductive Event |
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| Sexuality Mode(s) | |||
| Mode(s) of Asexual Reproduction |
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| Fertilization Type(s) | |||
| More than One Reproduction Event per Year |
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| Reproductive Startegy | |||
| Egg/Seed Form |
Impacts
Economic Impacts in Chesapeake Bay
Economic and ecological impacts of Oncorhynchus mykiss (Rainbow Trout) are minor in the Bay proper, but important in trout streams in the watershed. Most Chesapeake drainage populations have limited reproduction and are heavily dependent on stocking (Jenkins and Burkhead 1993; Musick 1972)
Reerences - Jenkins and Burkhead 1993; Musick 1972
Economic Impacts Outside of Chesapeake Bay
Oncorhynchus mykiss (Rainbow Trout) is a major sport fish throughout the United States and much of the world in cold-water streams and lakes (Page and Burr 1991; Scott and Crossman 1973). Oncorhynchus mykiss have been introduced to drainages outside their native range in 50 U.S. states (Fuller et al. 1999) and most Canadian provinces, and to waters on all continents except Antarctica (Lever 1996). This species is also becoming an increasing important aquaculture fish, in suitable fresh and salt waters.
References- Fuller et al. 1999; Lever 1996; Page and Burr 1991; Scott and Crossman 1973
Ecological Impacts on Chesapeake Native Species
Oncorhynchus mykiss (Rainbow Trout) is established in some upland streams in the Chesapeake Bay watershed, but is largely dependent on stocking elsewhere. It may be locally important as a predator on native fishes and a competitor with native Salvelinus fontinalis (Brook Trout) in streams well above the Fall-Line, but it is only a stray in tidal waters (Jenkins and Burkhead 1993; Musick 1972a).
References- Jenkins and Burkhead 1993; Musick 1972a
Ecological Impacts on Other Chesapeake Non-Native Species
Oncorhynchus mykiss (Rainbow Trout) is established in some upland streams, but is largely dependent on stocking elsewhere. It may be locally important as a predator on small introduced fishes and a competitor with other stocked salmonids [Oncorhynchus clarki (Cutthroat Trout); Salmo trutta (Brown Trout)) in streams well above the Fall-Line, but it is only a stray in tidal waters (Jenkins and Burkhead 1993; Musick 1972a).
References- Jenkins and Burkhead 1993; Musick 1972a
References
Bean, Tarleton H. (1896) Report on the propagation and distribution of food-fishes, In: (Eds.) Report of the United States Commission of Fish and Fisheries for 1894. , Washington, D.C.. Pp.Bridger, C. J.; Booth, R. S.; Mckinley & Scrut, D. A. (2001) Site fidelity and dispersal patterns of domestic triploid steelhead trout (Oncorhynchus mykiss , Walbaum) released to the wild, ICES Journal of Marine Science 58: 510-516
Carlander, Kenneth D. (1969) Handbook of freshwater fishery biology. Vol. 1., In: (Eds.) . , Ames. Pp.
Cope, Edward Drinker (1879) The Fishes of Pennsylvania, In: (Eds.) Report of the State Commisioners of Fisheries. , Harrisburg. Pp.
Courtenay, Walter R., Jr.; Hensley, Dannie A.; Taylor, Jeffrey; McCann, James A. (1984) Distribution of exotic fishes in the continental United States., In: Courtenay, Walter R., and Stauffer, Jay R.(Eds.) Distribution, Biology, and Management of Exotic Fishes. , Baltimore, MD. Pp.
Fuller, Pam. L.; Nico, Leo; Williams, J. D. (1999) Nonindigenous fishes introduced into inland waters of the United States, , Bethesda MD. Pp.
Jenkins, Robert E.; Burkhead, Noel M. (1993) Freshwater fishes of Virginia., , Bethesda, MD. Pp.
Lee, David S. (1976) Aquatic zoogeography of Maryland, Atlantic Naturalist 31: 147-158
Lee, David S.; Gilbert, Carter R.; Hocutt, Charles H.; Jenkins, Robert E.; McAllister, Don E.; Stauffer, Jay R. (1980) Atlas of North American Freshwater Fishes, , Raleigh. Pp.
Lee, David S.; Platania, S. P.; Gilbert, Carter R.; Franz, Richard; Norden, Arnold (1981) A revised list of the freshwater fishes of Maryland and Delaware, Proceedings of the Southeastern Fishes Council 3: 1-9
Lever, Christopher (1996) Naturalized fishes of the world., , London, England. Pp.
Mansueti, Romeo J. (1950) An ecological and distributional study of the fishes of the Patuxent River watershed, Maryland, , College Park, Maryland. Pp.
McKeown, Paul E. (1984) Additions to ichthyofauna of the Susquehanna River with a checklist of fishes of the Susquehanna River drainage below Conowingo Dam, Proceedings of the Pennsylvania Academy of Science 58: 187-192
Musick, J. A.; Wiley, Martin L. (1972) Fishes of Chesapeake Bay and the adjacent coastal plain, Special Scientific Report, Virginia Institute of Marine Science 65: 175-212
Page, Lawrence M.; Burr, Brooks M. (1991) Freshwater Fishes., , Boston. Pp.
Pavol, Kenneth W.; Davis, Robert W. (1982) An investigation of the smallmouth bass in the Susquehanna River below Conowingo Dam, F-29R , Annapolis MD. Pp.
Raasch, Maynard S.; Altemus, Vaughn L., Sr. (1991) Delaware's freshwater and brackish water fishes: a popular account, , Wilmingotn, Delaware. Pp.
Schwartz, Frank J. (1965) Natural salinity tolerances of some freshwater fishes, Underwater Naturalist 2: 13-15
Scott, W. B.; Crossman, E. J. (1973) Freshwater fishes of Canada, , Ottawa. Pp.
Smiley, Charles W. (1884) A statistical review of the production and distribution to public waters of young fish, by the United States Fish Commission, from its organization, to the close of 1880., Report of the United States Commission on Fish and Fisheries for 1881 :
Susquehanna River Anadromous Fish Restoration Committee (1997) Restoration of American Shad to the Susquehanna River, , . Pp.