The Arkansas darter is a small, 2.5 inch fish in the perch family native to portions of the Arkansas River basin. Its upper body is brown, and its back has many fine, black specks. It has a dark, vertical wedge-shaped spot beneath its eye. Its body has 12 to 14 dusky stripes along the sides. Its belly is nearly white, except in breeding males in which it becomes bright orange. The Arkansas darter’s range includes sites in extreme northwestern Arkansas, southwestern Missouri, and northeastern Oklahoma, within the Neosho River watershed. It also occurs in a number of watersheds and isolated streams in eastern Colorado, south-central and southwestern Kansas, and the Cimarron watershed in northwest Oklahoma.