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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.

Troutperches (Percopsids)

Sand roller (Percopsis transmontana)


The sand roller, one of two species in the family, is found in the Columbia River system and some tributaries from the middle Columbia River in Washington downstream to within 40 km above the mouth. This species was recorded from the Clearwater River in Idaho in 1952. It was collected from the fish ladder at the old WWP dam near Lewiston and above the dam to the mouth of Hatwai Creek. The habitat typically is slow moving portions of streams and rivers with a mud-sand bottom often near undercut banks, although it has been found over a rubble substrate with considerable aquatic vegetation. Little is known about the life history of this species, but apparently its food consists of aquatic invertebrates. It is a small species, reaching 3 - 4 inches in total length. The species probably is uncommon to rare throughout its range. Repeated attempts to collect sand rollers from the Clearwater River and lower tributaries have failed and none have been reported since the removal of the WWP dam in 1973. This species may well have disappeared from Idaho waters.

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