Color of Blue Catfish, as its name implies, is blue or slate-gray above and light below. The body has no dark spots that are characteristic of Channel Catfish. The upper jaw protrudes slightly beyond the lower, and the head is prominently convex. The anal fin is very long, and its basal length is about one-third the standard length of the fish. Blue Catfish are easily distinguished from the Channel Catfish by the number of rays in the anal fin, Channel Catfish having 24 to 29 rays -blue catfish from 30 to 35. The tail is deeply forked and the eyes are small. The air bladder has three lobes or parts, an anterior pair joined side by side and the smaller third lobe is placed behind.
Blue Catfish, not to be confused with the "blue" color phase of the male Channel Catfish, is indigenous to the southern United States and is rarely found in the lower reaches of the Mississippi River in Iowa. Primarily a "big river" fish species, no specimens have been collected from any of the interior streams, although this fish might very well inhabit the lower Des Moines River. It has been documented in the majority of the Missouri River, and has been collected in Lake Manawa in the past. Blue Catfish were stocked in Big Creek Lake in Polk County in 1972, but none were reported as caught.
Frogs, insects, crayfish, worms, host of other living and dead material.
101 lbs.; 53 in. - Missouri River, Mills County, June 2004 - Mike Rush, Bellevue, NE
Primarily a "big river" fish species, the Blue Catfish is found almost exclusively in the Missouri and Mississippi Rivers. It was formerly abundant near Keokuk, Iowa during the summer months but, as a migratory species, it has declined due to the construction of dams.
The Blue Catfish inhabits rivers, large permanent streams, swift chutes, over-bars, pools, runs, raceways, ponds, lakes and oxbows. It is associated with large rivers with moderate to swift current, in the main channel and the main channel border . The Blue Catfish avoids the silted bottoms of most sluggish pools, preferring firm substrates of bedrock, boulder, sand or gravel, but does inhabit the deep waters of large reservoirs.
Blue Catfish spawn in June and early July when the water temperatures are 70 to 75 degrees F. They construct nests similar to those of Channel Catfish. The young attain a length of from 2 1/2 to 4 inches at the end of the first growing season. Adults are among our largest freshwater fishes and specimens weighing nearly 100 pounds have been taken from the lower reaches of the Missouri River. While fish of this size are rare, adults weighing up to 20 or 25 pounds are quite common.
The range of natural foods consumed by Blue Catfish is indeed very wide. They live principally upon aquatic insects and their larvae, crayfish, worms, frogs, small freshwater mussels, fish and a host of other living and dead material. Like Channel Catfish, they are omnivorous in their feeding and take everything that is available and palatable.
Recent stream sampling has not resulted in the discovery of any individual Blue Catfish, however, this species is more common in large rivers than streams. Complete stream sampling information is available from Iowa DNR's biological monitoring and assessment program.
Like the other catfish species in Iowa, these fish are highly sought after by anglers. It is viewed as apparently secure according to the Iowa Wildlife Action Plan.
Harlan, J.R., E.B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323pp.
Iowa Department of Natural Resources, Iowa Wildlife Action Plan
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.
Photo credit: photo courtesy of Konrad P. Schmidt, copyright Konrad P. Schmidt.