SHEBOYGAN, Wis. (AP) – An invasive snail has been found in a trout stream in Dane County, spurring fears that it could spread to other Wisconsin waterways. A Sheboygan Press Media report says state wildlife officials are advising outdoor enthusiasts to take precautions to limit its spread. The New Zealand mud snail was discovered last month in Black Earth Creek, which is popular for trout fishing. The snail is about the size of a grain of sand but it reproduces so quickly that biologists say it could significantly alter the food chain. They can also spread quickly, for example in a clump of mud on a fisherman’s waders. They can survive for weeks without water, so officials ask anglers to freeze their equipment for eight hours or clean and dry their gear thoroughly.