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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.

Weatherfish (Cobitidae)

Oriental weatherfish (Misgurnus anguillicaudatus)


The Chinese loach is an exotic, aquarium species that has established itself in the lower Boise and Payette rivers and associated irrigation ditches. They were introduced by people getting rid of their pets in local water ways. It has several common names including: Chinese weatherfish, Chinese loach, or dojo loach. There are two species distributed as weatherfish, but this one is most likely Misgurnus anguillicaudatus. They can survive the area winters and have been reproducing in Idaho for some time. These fish can survive over the winter in de-watered ditches by burying into the mud, and emerging again the following spring after the water is turned back on. Their effect (if any) on native Idaho fishes is currently unknown. The species is native to eastern Asia and is omnivorous. They prefer still water or slow flowing streams with mud substrates. The origin of the name weatherfish is due to their habit of responding to changes in barometric pressure by becoming very active and swimming in rapid circles just before major weather changes.

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