Freshwater Mussels Pacific Northwest - State Water Resources ...

The John Day River is home to the California floater. photo: Dennis FratesCalifornia FloaterAnodonta californiensis Lea, 1852DescriptionSize: Up to five inches.Shape: Elliptical or ovate; L:H ratio usually less than 1.5. Laterally inflated.Valves slightly compressed toward the posterior dorsal margin, broad, andraised to form a “wing”. Valves are thin and fragile.Beaks: Small; scarcely elevated above the hinge line.Periostracum: Color olive, pale brown, reddish brown, or black. There aregreenish rays on the posterior slope. The periostracum is smooth and growthlines are prominent.Hinge Teeth: NoneNacre: Usually white, but sometimes with a flesh-colored or purplish tint.DistributionThe native range of the California floater extended from Baja California tosouthern British Columbia, and east to western Wyoming, eastern Arizona,and Chihuahua (Mexico). It was originally widespread in California, but itsdistribution is now greatly reduced. It was once distributed throughout sixmajor drainages in Arizona, but today only remnant populations are thoughtto exist in portions of the Black River drainage and Little Colorado River. In24Freshwater Mussels of the Pacific Northwest