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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.

Minnows (Cyprinids)

Lake chub (Couesius plumbeus)


The lake chub, a 4 to 5 inch member of the minnow family, occurs across Canada, Alaska and the northern U.S. from New York to Washington. In Idaho, it is native only to the Kootenai River system. It generally is found in a variety of habitats in lakes and streams, but in Idaho it prefers the smaller streams to the main Kootenai. Spawning occurs in late spring and non-adhesive eggs are deposited in areas of coarse gravel or small rubble. Apparently they feed mainly on zooplankton and aquatic insect larvae. In some parts of its range, this species is an important forage fish for larger predaceous fish and is used as a baitfish. In Idaho, however, the species does not occur in areas that support large populations of predator fish.

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