The mud darter (Etheostoma asprigene) is a species of darter endemic to the lowlands of the Mississippi River basin from Wisconsin and Minnesota south to Louisiana and East Texas. It is also found in the drainages of the Sabine and Neches Rivers of Texas and Louisiana. It can be found in slow-moving waters on riffles in rivers, as well as in creeks, swamps, lakes, and reservoirs. It mostly consumes the larvae of midges and blackflies.