Neosho Madtom

Noturus placidus


Neosho Madtom
Joseph R. Tomelleri. Used with permission.
Species of Conservation Concern

Ictaluridae (bullhead catfishes) in the order Siluriformes (catfishes)


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.


Length: to 3 inches

Habitat and conservation

Inhabits medium-sized to moderately large streams with moderate gradients, permanent flow and clear water. Adults are found on riffles, where loosely packed gravel provides crevices in which they hide. Young live in quieter waters. This species is vulnerable to drought, pollution and habitat changes due to reservoir construction, agricultural runoff, mining and more.


Neosho madtoms hide during the day and come out at night to search for aquatic insects including the larvae of caddisflies, mayflies, flies and midges. They feed most actively within the three hours after sunset.

image of Neosho Madtom distribution map
Distribution in Missouri

While the entire distribution of the Neosho madtom is 250-300 stream miles of the Arkansas River basin, this species is peripheral in Missouri, inhabiting only 5 to 7 stream miles on the Spring River.


Endangered (state); Threatened (federal). This survival of this species is jeopardized by reservoir construction, gravel dredging, dewatering for municipal and agricultural purposes and deteriorating water quality due to zinc-lead mining, agricultural runoff and increased urbanization and industrialization.

Life cycle

Egg development begins in March. Spawning typically takes place in June and July, which coincides with the period of peak streamflow in the Neosho River drainage. Madtoms make cavity nests in protected hiding places. After the eggs are laid, they are guarded by one or both parents. Some madtoms also guard newly hatched fish. Large numbers of young madtoms have been observed in the quiet water below riffles, suggesting that young-of-the-year fish probably drift downstream to develop.

Human connections

Although it apparently has never been very abundant in the waters of our state, the Neosho madtom represents a precious, unique and irreplaceable component of our Ozark waterways.

Ecosystem connections

This small catfish controls populations of aquatic insects as well as flying insects, since many flying insects begin life as aquatic larvae. Meanwhile, larger animals, including fish, mammals and birds, prey on this small catfish.