Carnivorous Fish Found in Rock River

A carnivorous fish is prowling the waters of the Rock River near Janesville, and the Wisconsin Department of Natural Resources says if they find more of them, they could have a devastating effect on that body of water.

It's called a giant snakehead fish, native to tropical waters of Asia. The DNR's discovery of the giant snakehead near Janesville earlier this month was the first such discovery in Wisconsin's history.

The DNR says the giant snakehead was most likely released into the river by a hobbyist after the fish outgrew its aquarium. They say while they're alarmed in finding the snakehead, they say the fish would have a hard time surviving the cold water of a Wisconsin winter. The DNR will resume its search for the giant snakehead once the water cools considerably. In the meantime, the DNR urges anglers to report any suspicious fish they may see.

Wisconsin law prohibits the release of aquarium fish, like a giant snakehead, into the wild. Wisconsin DNR experts say so far there's no evidence of the fish existing in Illinois.