The brown madtom is a widely distributed and relatively common member of the madtoms. This diminutive catﬁsh may be used in bait ﬁshing for bass and is prominent in moderate- to fast-ﬂowing water.
The brown madtom is dull colored. The upper body possesses a chocolate brown or yellowish-brown tint. The ventral side is pale. Juvenile brown madtoms, especially those collected in complex leaf debris or vegetation, may be black. These ﬁsh will adjust the intensity of their body color to simulate shades of their surroundings. The upper lip of the brown madtom protrudes beyond that of the lower lip, and the rear of the pectoral spine has six sawlike teeth.
Male and female brown madtoms grow at the same rate, but males reach a larger overall length because they live longer. The largest individual collected to date was a male that measured 6 inches in total length. Females live at least 3 years, while males may live 4 or 5 years. The total length of a 3-year-old ﬁsh ranges from 3.9 to 5.1 inches.
Spawning, as determined in northern Mississippi river, takes place from May through July.
Brown madtoms exhibit crepuscular feeding, with peak feeding activity following sunset and just before sunrise. The diet, similar to other madtoms, is primarily composed of midge larvae, caddisﬂy larvae, and crayﬁsh.
The brown madtom has a fairly wide distribution covering the following areas: Mississippi River tributaries in Kentucky, Tennessee, Mississippi, and Alabama; Tennessee River tributaries in Tennessee and Alabama; the Gulf Slope in the Sabine River drainage of Louisiana; and Bayou Teche drainage in Louisiana. It has also been reported in the Ouachita River drainage in Arkansas, probably introduced with other baitﬁsh. In areas where brown madtoms are collected, they are usually abundant.
This species is usually abundant in springs and small streams where areas of vegetation exist, in accumulations of debris, and underneath undercut banks. Madtoms in one stream in northern Mississippi preferred undercut banks to all other types of cover. Brown madtoms can be found in moderate- to fast-ﬂowing water over small gravel or coarse sand.