Blue Catfish

Characteristics

Blue Catfish, as its name implies, are 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 curved. 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 have 24 to 29 rays - Blue Catfish 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.

Distribution

Blue Catfish, not to be confused with the "blue" color phase of the male Channel Catfish, is native 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 fish have been collected from any of the interior streams, although this fish might live in 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.

Foods

Mostly aquatic insects and their larvae, crayfish, worms, frogs, small freshwater mussels, fish and many other living and dead material. Like Channel Catfish, they are omnivorous in their feeding and take everything that is available and tasty.

State Record

101 lbs.; 53 in. - Missouri River, Mills County, June 2004 - Mike Rush, Bellevue, NE

Expert Tip

None

Details

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 during the summer months but, as a migratory species, it has declined due to the construction of dams.

Blue Catfish live in rivers, large permanent streams, swift chutes, over-bars, pools, runs, raceways, ponds, lakes and oxbows. It can be found in large rivers with moderate to swift current, in the main channel and the main channel border. It avoids the silted bottoms of most sluggish pools, preferring firm substrates of bedrock, boulder, sand or gravel, but does live in the deep waters of large reservoirs.

Blue Catfish spawn in June and early July when the water temperatures are 70 to 75 degrees. They build nests similar to those of Channel Catfish. The young reach 2 1/2- to 4-inches long at the end of the first growing season. Adults are among our largest freshwater fishes; fish weighing almost 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 common.

Recent stream sampling has not resulted in the discovery of any individual Blue Catfish. This species is more common in large rivers than streams.

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.

Sources:

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.