Lampsilis cardium is a species of freshwater mussel in the family Unionidae, the river mussels.

[2] It is widespread in eastern North America, where it is native to the Mississippi River and Great Lakes drainage systems.

All Unionidae are known to use the gills, fins, or skin of a host fish for nutrients during the larval glochidia stage.

Lampsilis cardium accomplishes this by having the inner sides of its mantle flaps marked with longitudinal stripes, resembling a small fish of the genus Notropis.

When these are attacked and ruptured by a striking predator fish, especially Micropterus coosae, the mussel larva is released into the gills of the host fish where it feeds and develops.