Noturus exilis Nelson 1876
Identification: The Slender Madtom has black borders on light yellow fins. Fin borders are blackest in clear streams and may be only dusky in color in turbid water. The body is yellow-brown to gray-black above and light yellow below. There is a large light yellow spot on the nape and a smaller one on the rear of the dorsal fin base. The body is slender, and the mouth is terminal with equal jaws. The rear edge of the pectoral spine has large teeth. The caudal fin edge is straight or slightly rounded. The anal fin has 17-22 rays. To 5 3/4 in. (15 cm) total length.
Range: The Slender Madtom is found in the Green, Cumberland, and Tennessee River drainages in Kentucky, Tennessee, and northern Alabama, and in the upper Mississippi River basin from southern Wisconsin and southern Minnesota to the Ozark and Ouachita Highlands of Arkansas, Kansas, and Oklahoma. This species is fairly common but localized.
Habitat: The Slender Madtom inhabits rocky riffles, runs, and flowing pools of clear creeks and small rivers, and is occasionally found along wave-swept shores of large impoundments.
Similar species: The Margined Madtom, Noturus insignis, is the only other madtom to have black borders on its fins, but differs from the Slender Madtom in that the upper jaw projects beyond lower jaw and there is no light spot on the nape or at the rear of the dorsal fin base.