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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)

Longnose sucker (Catostomus catostomus)


The longnose sucker is widely distributed from Siberia and Alaska across Canada and the northern U.S. In Idaho, it is found in the Kootenai, Pend Oreille, and Coeur d'Alene River systems. It is found in cold-water lakes and streams. The young may inhabit shallow weedy areas, but older fish generally are found in deeper water. Spawning occurs in riffle areas of streams. Females produce 14,000 to 60,000 eggs. Young fish apparently feed to a great extent on plant material. Older fish take mainly a variety of benthic invertebrates. Individuals may reach 25 inches and 7 pounds in parts of their range, but in Idaho they seldom are larger than 12 to 14 inches and 3 pounds. In some areas of its range, this species is fished commercially for human consumption. Because of its restricted range and the greater abundance of more desirable game fish, in Idaho this species is not used as a food fish.

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