Tadpole madtom

Tadpole madtom


The Tadpole Madtom is dark olive to brown. Its head is large and fleshy, not flattened. The anal fin has 13-15 rays. It has a narrow, dark line along side of body. It rarely exceeds 3-4 inches in length.


Tadpole madtom Distribution

Eastern two-thirds of state, in large interior rivers and the Mississippi River


Insects, occasionally algae and other aquatic plants

State Record


Expert Tip



The Tadpole Madtom is widely distributed in the large interior rivers and the Mississippi River. Populations reach their greatest abundance in the small, rocky, clear-water streams, mainly in the northeastern and northcentral regions. Its presence in many of the oxbow lakes along the Missouri shows that it is also present in the parent stream. This species is occasionally taken in the natural and man-made lakes of the state.

Color of the Tadpole Madtom varies from dark olive or brown to sometimes dark gray and light beneath. The head is large and fleshy and not flattened. The body is short and stout. It more looks more like a bullhead than either of the other madtoms. There are 13 to 15, usually 14, rays in the anal fin. The premaxillary band is bar shaped. There is a very narrow dark line along the side of the body. Upper and lower jaws are of equal length. This little fish rarely exceeds 3 or 4 inches in length.

Female madtoms usually mate several times during the June through July breeding period. Young fish have been taken in collections in late fall measuring about one inch long. Most individuals probably mature during their second summer and few live beyond their third summer.

Like most madtoms, this species is most active at night, feeding on insects, and occasionally on algae and other aquatic plants. These catfishes, as well as the other madtoms, have a poison gland at the base of the pectoral fin. When one is stung or pricked by one of the spines, there is a burning sensation similar to a bee or wasp sting.

Present in these Iowa water bodies:
Lake/Stream County Location Acres/Length
Clear Lake Cerro Gordo south edge of Clear Lake 3684.00
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
Missouri River (Little Sioux to Council Bluffs) Pottawattamie Wilson Island State Recreation Area: 32801 Campground Lane/Missouri Valley, IA 51555 phone-712-642-2069. Managed by the Iowa Department of Natural Resources, Wilson Island Recreation Area has 544 acres along the Missouri River near Missouri Valley Iowa. 53.00