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Fishes of Idaho

How are your identification skills? Do you know which are native and which were introduced? To see photos and descriptions, and learn more about Idaho fish, check out our Fishes of Idaho online database.

There are around 20,000 species of fish in the world. About 58% of these are marine (saltwater) fish, 41% are freshwater fish, and 1% are both. We have around 100 species in Idaho, and the list keeps growing as more non-native fish are released into Idaho waters. There are only 39 species of fish native to Idaho. The rest were introduced--some by accident, but most on purpose.


Rainbow trout (Oncorhynchus mykiss)


Known for an aggressive fight and excellent taste, rainbow trout are one of the most popular sport fishes in North America. Coloration varies with size and habitat, but rainbows usually have a pink or reddish band along their sides and white tipped fins. Rainbow trout are native to the Pacific coastal states and provinces of North America, and to much of the Rocky Mountains west of the continental divide. Rainbow trout are an adaptable species that has been widely transplanted and is now found in lakes, large rivers, and small streams throughout the world. Rainbow trout have been very successfully domesticated and are widely utilized by fishery management agencies to supplement sport fisheries. They are also an important commercial aquaculture species in Idaho, particularly in the Magic Valley region. The anadromous form (ocean-going) of the rainbow trout is known as the steelhead.

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