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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.


Pygmy whitefish (Prosopium coulterii)


The pygmy whitefish has a disjunct distribution across the US and Canada. These fish can be found in Lake Superior in the central US and Canada, and in river systems in Alaska, Montana, Idaho and Washington. Pygmy whitefish are also found in Canadian river systems in Alberta, British Columbia and Yukon Territories. Adult pygmy whitefish reach maximum sizes of about 10 inches and spawn in late fall or early winter. Primary foods of pygmy whitefish are crustaceans and aquatic insect larvae. Although these small whitefish are not a highly sought for food or as sportfish for people, they provide an important source of food for other fish such as bull, rainbow, brown, and lake trout in Idaho.

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