Flathead Catfish

Characteristics

Dark to olive-brown with dark brownish mottlings on the sides, especially in younger fish. After living in waters that flow over sand or light bottoms, adults are often light tan or even yellowish in color. The anal fin is very short with only 15 to 17 rays. The head is broad and flat, and the tail is square or very slightly notched. The jaws are heavy, and the lower jaw is longer than the upper.

Distribution

Found in most large interior streams of Iowa and in the flood control reservoirs (Coralville, Saylorville, Rathbun and Red Rock). One of the most abundant large catfishes of the Mississippi and Missouri Rivers. It is almost absent from the interior streams of the Missouri River basin and rare in natural lakes, man-made lakes and reservoirs.

Foods

Insect larvae, crayfish, mollusks, fish, worms, and terrestrial animals that wash into the streams. Small catfish, 8- to 10-inches long, have been seen feeding extensively on schools of young minnows in the shallow water. Large flatheads, more than 20 inches long, are almost wholly fish-eating, taking live or dead fish from the bottom.

State Record

81 lbs; 52 in. - Ellis Lake, Lucas County, June 1958 - Joe Baze, Chariton, Iowa

Expert Tip

Try fishing with small sunfish under cut banks after dark; use strong hooks.

Details

The Flathead Catfish lives in a variety of habitats and can tolerate extreme turbidity, but avoids headwater creeks, high gradient streams and strong currents. During the day it is usually found next to deep pools created by strong current in large sluggish rivers, or low gradient tributaries of large streams. In Iowa, the Flathead Catfish is found mainly in mud-bottomed areas and deep waters in pools. The Flathead Catfish also lives in reservoirs, but is more plentiful below dams of major impoundments. It is usually found by drift piles, submerged logs or fallen trees with hard-bottomed substrates of sand or silt. Riffles are used by night feeding adults and are the main habitat of young, which also stay in pools, backwaters and sheltered places as they mature.

Spawning occurs in June and July in secluded hides and obscure places. These fish are nest builders, and parent fish guard the eggs and young. The young reach 2- to 6-inches long the first year and are sexually mature in the third or fourth year of life. Adults grow to enormous size. Reports of huge flatheads of more than 100 pounds have been passed along through generation along the Mississippi River, but efforts to document their truth have been difficult.

Flathead Catfish are harvested by commercial fishermen from the Mississippi River. About 85,000 pounds of Flathead Catfish valued at over $40,000 are annually harvested from the Mississippi River.

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

Sources:

Harlan, J.R., E.B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323pp.

Loan-Wilsey, A. K., C. L. Pierce, K. L. Kane, P. D. Brown and R. L. McNeely. 2005. The Iowa Aquatic Gap Analysis Project Final Report. Iowa Cooperative Fish and Wildlife Research Unit, Iowa State University, Ames

Illustration by Maynard Reece, from Iowa Fish and Fishing