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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.

Suckers (Catostomids)

Mountain sucker (Catostomus platyrhynchus)


The mountain sucker is found throughout the mountainous regions of the west from the Lahontan and Bonneville basins of CA, NV, and UT through the Columbia and Missouri drainages of British Columbia, WN, ID, MT, and WY. It is widespread throughout the Snake and Bear River systems in Idaho. It occurs in a wide variety of habitats, but usually prefers cool, clear streams with clean rubble or sand bottoms. It is occassionally found in lakes. Spawning occurs in late spring/early summer in riffles of clear, swift streams. Females produce from 600 to about 3,000 eggs, depending on their size. This is a small sucker, seldom growing larger than 8 inches. The food of this species is almost entirely algae that is scraped off rocks by the cartilaginous sheath on the jaws. Mountain suckers may be forage for trout, and thus, an important link in the food chain from plants to predaceous fishes.

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