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Invasive signal crayfish discovered for first time in Minnesota waters

Invasive signal crayfish spotted in lake near Alexandria
Invasive signal crayfish spotted in lake near Alexandria 00:20

ALEXANDRIA, Minn. — Wildlife experts are dealing with a new potential threat in Minnesota's waterways.

The Minnesota Department of Natural Resources says for the first time, the signal crayfish has been found in a state lake.

Trappers caught 10 of them in Lake Winona, near Alexandria.  

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MN DNR

The DNR says signal crayfish are bigger and more aggressive than crayfish native to Minnesota. They can spread between connected waterways and by people, and can "crawl over land at night during wet weather," the DNR says.

Signal crayfish are bluish-brown to reddish-brown, with patches near the hinges of their claws that resemble a signal flag.

The DNR asks anyone who spots them to write down the exact location, snap a photo, and even "keep the specimen" and contact them.

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