Distribution: This once widespread species is now thought to be restricted to 4-5 isolated populations in the St. Croix River in Minnesota and Wisconsin, the Bourbeuse River in Missouri, the Saline and Ouachita Rivers in Arkansas, and the Little River in Oklahoma. Questionable records exist from the Kiamichi River, but no live individuals have been found in recent years.

Life History and Ecology: Riffle areas in medium to large rivers. Short-term brooder that is thought to use blue and channel catfish as hosts. Equilibrium life history strategy.

Special Status: US Federally Endangered

Shell Description: click here for shell description