Freshwater Mussels, kinda like clams, live in lakes and rivers. Cook the same as clams or oysters. Do not eat mussels unless you are sure they are throughly cooked. Diseases these things could carry could include typhoid and cholera. Since they live in the mud, any raw sewage these are exposed to will be taken in by the mussel. Some pictures I took last weekend are below.
Went to a casino one time and had their buffet meal. It was seafood night and for the most part the food was good. That is until I decided to try clams and mussels. Nasty things. The only way I like clams is in a nice New England chowder. Don't go for that other clam chowder. And as far as the mussels go, never will I eat them again. I'll stick with oysters. Much better and they have a surprise inside. Hahaha.