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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)

Bluehead sucker (Catostomus discobolus)


The bluehead sucker is native to the Colorado River basin, and the ancient Lake Bonneville basin in UT, ID, and WY. In Idaho, this species occurs in the Snake River system above Shoshone Falls. It is a fluvial (flowing water) species, occurring in a variety of habitats, ranging from cold, clear trout streams to warm, vary turbid waters. It prefers riffle areas with rocky substrates. Little is known about the life history or biology of this species. They spawn in late spring/early summer and probably scrapes its food off rocks. Although this sucker may reach 16 inches in length, Idaho specimens generally are not more than 11 to 12 inches. They are relatively rare in Idaho waters.

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