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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)

Tench (Tinca tinca)

Non-native

The tench is native to streams and lakes of Europe. It was cultivated in the U.S. as early as 1883. The species was introduced into northern Idaho in the late 1880's. Currently they are found in the Pend Oreille and Coeur d'Alene River systems and at least one farm pond in Latah County. This species inhabits the shallow areas of lakes and slow-moving rivers where aquatic vegetation is abundant. They can tolerate poorly oxygenated waters. Very little is known about their life history in the U.S. Spawning probably occurs in shallow, weedy areas in late spring - summer. Eggs, up to 250,000 per female, sink and stick to the bottom substrate or aquatic vegetation. The species is omnivorous, feeding on plant material and aquatic invertebrates. Individuals up to 15 inches in length have been recorded from Idaho. Tench are valued in Europe by some anglers, others consider it a food fish, and it has use in pond cultures, both as food and as an ornamental fish. It apparently has none of these values in the U.S. and is generally ignored.

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