The Neosho madtom is the smallest catfish in Missouri. Adults are commonly 1.8 to 2.7 inches long to a maximum of three inches. It looks similar to the brindled madtom. Both have mottled dark- and light-brown coloration with dark, vertical bars on the caudal fin. The best way to tell them apart is to observe the adipose fin (located dorsally in front of the tail fin). The dark color at the base of the fin does not extend to the outer edge of the fin in the Neosho madtom. And while the dorsal and anal fins of the Neosho madtom have dusky streaks, they are not black or dark-tipped as in the brindled madtom.