The club naiad, clubshell pearly mussel, or clubshell, scientific name Pleurobema clava, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species is endemic to the United States. Prior to its endangered status, club naiads could be found in the Ohio, Cumberland, and Tennessee River systems, and Lake Erie drainages. Currently, however, these mussels can be found in the United States in the states of Illinois, Indiana, Kentucky, Michigan, New York, Ohio, Pennsylvania, Tennessee, and West Virginia.