North Carolina Wildlife Resources Commission

Brook Floater (Lamarck, 1819)

Scientific Name: Alasmidonta varicosa

Classification:  State Endangered

Photo Credit: NCWRC




NOTE: Hover over the bold words for definitions or see the Glossary.

The brook floater is usually kidney-shaped and the shell is orange to brown with green rays, but shell color can vary to include green and blue.  The foot is bright orange.


Shell Anatomy

Found in four river basins in NC (Catawba, Pee Dee, Cape Fear, Neuse), the brook floater is also distributed along the Atlantic coast from SC to Canada.


Brook floaters prefer swift current in run-riffle complexes with clean gravel/sand/cobble substrates.

The host fish species include the margined madtom, pumpkinseed, golden shiner, and yellow perch. 

General Life History For Mussels

        Credit NCWRC for all photos.