Two species of freshwater mussels have been designated as endangered by the U.S. Fish and Wildlife Service. The mussels are only found in portions of the Cumberland and Tennessee River systems.
The agency designated 24 critical habitats in Kentucky, Tennessee and Virginia for the fluted kidneyshell, while 13 were designated for the slabside pearlymussel in Alabama, Mississippi, Tennessee and Virginia.
Under the Endangered Species Act, it's illegal to kill, harm or "take" a listed species. Fish and Wildlife evaluated factors that could cause extinction in deciding to list the mussels.
The agency says both mussels have a small number of populations that are considered biologically viable.