New records of Spotted Bass, , within the Mississippi River Basin, Illinois.

Spotted Bass , like many sport fishes, have experienced range expansion through intentional introductions (i.e., legal stocking and illegal transfers) and migration across the United States. In Illinois, USA, native populations of Spotted Bass occur along the eastern and southern border of the state. We report new records of Spotted Bass in their non-native range of the Illinois Waterway and the Illinois portion of the Upper Mississippi River in addition to collections in their native range in the Illinois sections of the Ohio and Wabash rivers to better understand their current distribution. Continuous, collaborative efforts to track the distribution and expansion of non-native fishes are important for maintaining and establishing native and non-native fisheries management objectives and education, as non-native fishes can influence native species population distribution and dynamics.