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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)

Redside shiner (Richardsonius balteatus)


The redside shiner is a western minnow found from northern British Columbia to southern OR and eastward to the Rocky Mountains. It foundthroughout the Columbia River drainage and the Bonneville basin. In Idaho, this species is found in all major river systems. It prefers ponds, lakes, ditches, springs, sloughs, and rivers where the current is slow or absent. Spawning usually occurs in early summer, when females move into shallow waters and broadcast eggs that sink to the bottom and adhere to the substrate. Females produce from 800 to 3,600 eggs each year. Shiners feed on small planktonic organisms, then switch to insects, mainly terrestrial, later in their life. Redside shiners attain 4 - 5 inches in length, although they can reach 6 to 7 inches in some localities. They are fed upon by a variety of fishes, especially the spiny-ray species, and fish-eating birds. Photo credits: J. Trainer

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