New Distributional Records of the Ohio Shrimp, Macrobrachium ohione Smith (Decapoda: Palaemonidae) in Arkansas

The Ohio shrimp (Macrobrachium ohione) is a migratory (amphidromous) river shrimp that occurs in some Arkansas rivers. It is known from the Upper Missouri River from its mouth downstream to the Gulf of Mexico, but shrimp abundance has declined, particularly upstream of Louisiana. Ohio Shrimp has also been collected in the lower reach of the Missouri River not far from the confluence of the Mississippi River in St. Louis County. Dams and alterations in channel flow are hypothesized to have impacted upriver migrations of shrimp. Current range, abundance, and life history of Ohio shrimp is relatively unknown in the Mississippi River basin in reaches distant from sea water. Here, we report recent collections of Ohio shrimp in Arkansas rivers that were notably greater than 800 km from the Gulf of Mexico.