Rainbow Trout

Not Every Rainbow Has A Pot Of Gold At The End Of It

Identification

Can range from size

Has a distinct rainbow reflection on the side of it

Lives in freshwater

Scientific Name: Oncorhynchus

Class: Actinopterygii

Order: Salmoniformes

Family: Salmonaide

Phylum: Chordata


Original Distribution: Japan

Current Distribution: San Diego

Ecological Role

Rainbow trout is a cool-to-cold water fish species that does best in freshwater systems below 70 degrees F. The anadromous form of the rainbow trout is called the steelhead. It is spawned in cold tributaries and then makes its way to salt water, or ocean ecosystems. At spawn time it migrates back up the same tributary of its birth to lay its own eggs.The rainbow trout are carnivorous but they do not necessarily feed on other fish alone; they have a wide variety of prey, including insects, crustaceans, mollusks, and small fish. The rainbow trout's primary predator is humans, who fish the trout for sport in practically every aquatic environment. The rainbow trout has been observed living at both deep depths in stream and river columns, while also feeding close to the surface. This shows that the trout is adaptable to varied conditions in its habitat, but it also demonstrates a deviation from the behavior of natural populations, whose individuals primarily occupy the base of the water column.




Benefits

Rainbow Trout are hardy fish that is well adaptable in many freshwater environments. It primarily provides recreational benefits to sport fishermen and anglers.





Threats

Rainbow trout is responsible for driving many native species into extinction or endangerment. They have eradicated frog species and threatened many native fish species in a variety of environments, such as the California golden trout and humpback chub in the Grand Canyon. Eliminating or diminishing other aquatic species in a given habitat can have drastic impacts on entire ecosystems, and the many trophic levels of terrestrial life forms that depend on aquatic systems for food.



Control Level Diagnosis:

Many methods of controlling rainbow trout populations involve individual fish removal from the environment. This includes specialized fishing, in other words, making laws that restrict fisherman to only keep rainbow trout and throw back the native species. Specialized removal has been practiced in the Grand Canyon, Yellowstone Lake, and the Shenandoah valley where, in 1998, 147 individual fish were removed. Because rainbow trout compete directly with other trout species, such as the brown trout, we can curb their spread by introducing them to the sport fishing environment at times when other fish spawning rates are high. Most obviously, prevention of further introduction will of course diminish the spread of the rainbow trout.


Site and Date of Introduction:

This species of trout was originally stocked in the Great Lakes around 1876 when they were planted in a tributary to Lake Huron. Since then they have been widely introduced in the Great Lake Basin and around the country. Hatchery propagation of rainbow trout was probably first carried out in the early 1870's by the California Acclimatization Society at a location about 20 miles south

of San Francisco. The first recorded shipment of rainbow trout outside their native range took place in 1874 when a small consignment.