Both Zebra Mussels and Asiatic Clams are exotic species in Alabama.
Zebra MusselDreissena polymorpha. Exotic. In Alabama, not reported outside of main channel of Tennessee River. Densities increasing slowly but steadily since early 1990s. Exotic.
Asian Clam or Asiatic Clam Corbicula fluminea. Exotic. Introduced in the mid-1900s and now found throughout Alabama. Densities vary, but may reach several hundred per square meter and may be cyclic with extensive mortality events reported regularly. Exotic.