I figured now that this thread is getting attention and I've found kind people willing to help me, I should probably post a quick tutorial on the only 2 bivalves that I don't study that might be confused with the native freshwater mussels I do study. The first is the Asian clam (pic below). It rarely grows larger than 1 inch and does not have the tell tale pearly inside like our many native mussels. The second I do not study is the zebra mussel. This clam rarely reaches a inch in size and hasn't spread across America as far and wide as the previous invasive species from Asia (thank god!). Where its found, its a huge nuisance. Pretty much, if you find a mussel that is larger than a inch and pearly inside, its definitely a native mussel.

Here is examples of the Asian Clam:
http://elrincondelmalacologo.iespana...20fluminea.jpg


Here is zebra mussels:

http://fl.biology.usgs.gov/Nonindige...l_FAQs/zm3.jpg
Here is a really nice pile of our native mussels:

http://www.nature.org/wherewework/no...protect_20.jpghttp://filebox.vt.edu/users/guyot/im...dt_mussels.jpg