The Wisconsin Department of Natural Resources says scientists have confirmed the invasive New Zealand mud snail has turned up in Dane County.
The DNR says the University of Wisconsin-La Crosse confirmed last month the snail was present in a sample agency biologists took from Black Earth Creek last year during routine monitoring for aquatic invasive species. The find marks the first time the creature has been discovered in an inland Midwestern stream.
The snail is the size of a grain of sand and has a black and brown shell. They out-compete native insects that serve as food for fish and other aquatic life.
The snails have previously been found in the western states and in the Great Lakes.