Freshwater mollusks of the middle Mississippi River

The middle Mississippi River (e.g., the area between its confluence with the Missouri River and its confluence with the Ohio River) was sampled for freshwater mollusks to obtain baseline data on the distribution of the assemblage. Forty sites were sampled in the middle Mississippi River during 2012 and 2013. A total of 28 species of mollusks, including 19 native species of freshwater mussels, four exotic bivalves, and five species of aquatic gastropods, were collected. Seventy-six individuals of six species of native freshwater mussels were collected alive in 80 person-hours of handpicking, and an additional six species were found as fresh-dead shell. Habitat instability (e.g., shifting sand) might explain the lack of freshwater mollusks in the middle Mississippi River.