Zebra mussel

The zebra mussel (Dreissena polymorpha) is a small freshwater mussel in the family Dreissenidae. The species originates from the lakes of southwestern Russia and southeastern Europe, but has been accidentally introduced to numerous other areas and has become an invasive species in many countries in the Northern Hemisphere. The adverse effects of dreissenid mussels on freshwater systems have led to their classification as among the world's most invasive aquatic species.

Main Photo Credit: "Zebra mussel (Dreissena polymorpha), Austria" by Wassersinn, 2026. CC BY-NC 2.0.

Description: Wikipedia