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Fish profile · Salmonidae
Rainbow trout
Oncorhynchus mykiss
Rainbow trout can spend its entire life in freshwater, while the migratory form, steelhead, grows at sea and returns to rivers to spawn. The forms belong to the same species. Unlike Pacific salmon, steelhead can survive to spawn more than once.
Last reviewed 26 October 2026 · 8 sources
- Max length
- 114.3 cm
- IUCN
- LC
- Least Concern
- Family
- Salmonidae
- order Salmoniformes
Category from the IUCN Red List, via GBIF (CC BY 4.0); it may lag the latest Red List assessment.
How big?
Linear scale · person 170 cm
Up to 114.3 cm.
How to identify
- Square tail covered in small dark spots arranged in radiating rows.
- White inside the mouth and on the gums.
- Spawning fish show a pink to reddish stripe along the side.
Habitat
Freshwater rivers and lakes support resident fish and spawning steelhead; migratory fish also use estuaries and the ocean.
- Diet
- Aquatic and terrestrial invertebrates, fish eggs, crustaceans and small fish.
- Native range
- Pacific-draining waters of western North America.
Catching it
- Season
- In the US, best in spring and early summer, especially in waters that are stocked.
- Methods
- Fly fishing
- Baits and lures
- SpinnersFliesPowerBait
More photos
Sources
Last reviewed 26 October 2026