The Mud Darter has a terminal mouth with small teeth on its jaws. The back is olive or brown with 8-11 dark blotches, or saddles, across the back. The side has 9-12 dark brown irregular vertical bars and the base of the tail has three spots arranged vertically. The belly is typically a cream or light olive color. They can reach a length of 7.1 cm (2.8 in), though most only reach a length of 5 cm (2.0 in).