HITTERDAL, Minn. -Two red swamp crayfish have been found in Tilde Lake just northeast of Hitterdal and it's the first time the invasive species has been confirmed in a Minnesota lake, according to the Minnesota Department of Natural Resources.
The live crayfish were removed from the lake and DNR staff are searching the lake for others, according to a DNR news release.
"Many aquarium animals and plants are invasive species that can cause serious harm if released into the wild," said Heidi Wolf, DNR invasive species unit supervisor, in the release.
She said the red swamp crayfish is an example of a prohibited invasive species that some online retailers ship to unsuspecting teachers for classroom aquariums or to people hosting "crawfish boils."
A permit is required to import crayfish - or almost any aquatic animals - for any purpose. Without a permit, it is illegal to import or possess red swamp crayfish in Minnesota, Wolf said in the release.
"We recommend people contact the DNR about legal alternative species," she added.
Red swamp crayfish compete with native species for habitat and eat tadpoles, snails and other small aquatic animals. Their burrowing habits make them extremely difficult to remove and cause damage to levees, dams and water control structures.