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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.


Mountain whitefish (Prosopium williamsoni)


Mountain whitefish are native to lakes and streams of western North America including Idaho. Adults are typically 10 to 16 inches in length and spawn in the fall or early winter. Mountain whitefish spend much of their time near the bottom of streams and feed mainly on aquatic insect larvae. These fish have been an important food fish for humans and provide a variety of angling opportunities ranging from dry fly to spin fishing.

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