The watercress darter is a small, very colorful fish measuring up to 2.5 inches in length. The fish is currently found in only five sites in the upper Black Warrior River drainage near Birmingham, Alabama. They are found only at mid-depths in dense accumulations of aquatic vegetation including watercress, in springs and spring runs. Green sunfish, bluegills, and sculpins are known to prey on watercress darters. The darters feed on snails, crustaceans, and insect larvae that inhabit springs and spring runs.