Pyganodon grandis, or the giant floater, is a species of freshwater mussel, an aquatic bivalve mollusk in the family Unionidae, the river mussels. This species is fast-growing, large, and has a short

Bivalvia or bivalves, in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of aquatic molluscs that have laterally compressed soft bodies enclosed by a calcified exosk