Unburned shells around the edges of the lime pits were mainly river mussels, but also included conchs and venus clams.

It is an aquatic bivalve mollusk in the family Unionidae, the river mussels.

This river mussel is now extinct.

This bivalve mollusc is in the family Unionidae, the river mussels.

Strophitus undulatus is a species of mussel in the Unionidae, the river mussels.

This river mussel needs gravel river beds and swift-flowing, well-oxygenated water.

Changing aquatic environments without proper sedimentation control does not only negatively affect river mussels, but most other freshwater species as well.

Before plastic buttons arrived, making buttons from river mussels was a major industry in Iowa river towns.

Obovaria retusa is a rare species of freshwater mussel in the family Unionidae, the river mussels.

The thick shelled river mussel declined during the 20th century everywhere in Europe due to deteriorating water quality, habitat fragmentation and host fish limitation.