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Slender madtom

Slender madtom


The body is yellowish on the sides and somewhat darker on the back. It has a white to cream-colored belly. The premaxillary band, or tooth patch on the upper jaw, is bar-shaped. The head is small, narrow and strongly depressed. There are 14 to 17 rays in the anal fin. No lateral stripe occurs along the side of the body. A light-colored, bar-shaped marking is on the back near the head and immediately above the dorsal fin. The upper jaw is somewhat longer than the lower. It can also be distinguished from other madtoms by the dark margin on the outer edges of the dorsal, anal and tail fins. It rarely exceeds 4- to 5-inches long.


Slender madtom Distribution

Major tributary streams of Mississippi River; most abundant in upper Des Moines River drainage.


Insects, aquatic plants

State Record

State Records are not documented for non-game species.

Expert Tip



Little is known about the life history of the Slender Madtom. It has been speculated that in spawning this fish deposits a small, compact cluster of eggs, probably no more than 100, into a shallow depression that was excavated beneath a flat rock, much like that of other madtoms. Eggs and newly hatched young are guarded by at least one of the parents, presumably the male like most Ictalurids. Slender Madtoms live entirely in riffle areas of small or medium size streams.

Recent stream sampling information is available from Iowa DNR's biological monitoring and assessment program.


Present in these Iowa water bodies:

Lake/Stream County Location Acres/Length
Missouri River (Sioux City to Little Sioux) Harrison Chris Larsen Park: 1280 Larsen Park Road/Sioux City, IA. Located on the Sioux City riverfront along the Missouri River. Larsen Park offers 110 acres on the Sioux City Riverfront. Managed by the City of Sioux City. 64.00
Missouri River (Council Bluffs to state line) Fremont Lake Manawa State Park: 1100 South Shore Drive/Council Bluffs, IA 51501 phone: 712-366-0220. Managed by the Iowa Department of Natural Resources Lake Manawa State Park has boat ramps on the Missouri River within the park. 61.00