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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)

Utah chub (Gila atraria)


The Utah chub is a minnow native to the ancient Bonneville basin of UT, ID, WY, and NV, and to the Snake River drainage above Shoshone Falls and the lower Wood River system. It recently has been reported near Boise in the Snake River below Shoshone Falls. This species occurs in lakes, reservoirs, and rivers, often associated with dense vegetation. Spawning occurs in late spring/early summer and eggs are scattered over various substrates in shallow water. Each female produces about 40,000 eggs. Utah chubs in Idaho typically reach a size of 7 to 10 inches in length. This species is an omnivore, feeding on aquatic plants, zooplankton, insects and crustaceans. Although the young may be forage for predaceous fishes, it is considered a nuisance species in Idaho. Attempts have been made to eradicate the species from important trout waters, but total kill is nearly impossible and populations rebound quickly after these attempts.

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