Aquatic Invertebrates of Montana

Lasmigona complanata (Barnes)

White heelsplitter

Recognition

The shell is easily recognized by its dorsal wing. The shell is solid, dark colored, tall and laterally compressed and it has white nacre white. The usual size is 120 to 140 mm.

Summary

This is probably a recent addition to the Montana fauna. In Beaver Creek, the new shells were first recognized by local ranchers about 1978. The abundant large shells of the lower Milk River population were first discovered in 1997 by Jim Liebelt with Montana Fish, Wildlife and Parks. The known hosts, carp and centrarchids, are all introduced in Montana. It occurs in fine mud in deep pools.

Distribution

Known only from the Lower Milk River and Beaver Creek, a tributary of the Little Missouri River. Outside of Montana this is a widespread species in the central part of the continent. It is also covered in the Field Guide to the Freshwater Mussels of the Midwest.

17 DEC 1995, updated on 4 AUG 1998 D.L. Gustafson