The oyster mussel (Epioblasma capsaeformis) is a rare species of freshwater mussel in the family Unionidae. This aquatic bivalve mollusk is native to Kentucky, Tennessee, Alabama, and Virginia in the United States. It has been extirpated from the states of Georgia and North Carolina. It is a federally listed endangered species of the United States. The main threat to this species is habitat alteration such as channelization and impoundments of waterways, increased silt, and pollution. This mussel is propagated in captivity. Many juveniles have been released into appropriate habitat.