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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.

Sculpins (Cottids)

Bear Lake sculpin (Cottus extensus)


The Bear Lake sculpin restricted to (endemic to) Bear Lake, ID/UT. It lives in association with the bottom, from the shallows to a depth of over 50 meters. Spawning occurs in the spring around rocks near shore. Females deposit eggs on the undersides of rocks. After spawning, the fish move to deeper water, up to 175 feet. The food of this species probably is similar to that of other sculpins. Adults attain a size of about 3 to 4 inches. This species is very important prey for rainbow trout, cutthroat trout, lake trout, and Bonneville whitefish in Bear Lake.

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