Latin name

Ictalurus furcatus

Other names

Catfish, chucklehead cat, white catfish, forktail cat, Mississippi cat, Fulton cat, blue Fulton cat, great blue cat, silver cat, blue channel cat, highfin blue cat.

Identification

Blue catfish are usually bluish-grey or slate-blue, without spots or other markings, although they can be almost pale blue or silvery blue. The colour of their flanks tapers towards the belly, which is pale grey or white. Their tail is deeply forked and their anal fins have straight edges. When small, they resemble channel catfish and are the most easily confused with this relative. The larger blue catfish has a distinctly humped back, with the hump on and in front of the dorsal fin. Its head is usually larger than that of the channel catfish and its body is less smooth. It can be distinguished from the channel catfish by its longer and straighter anal fin, which has 30 to 35 rays. Smaller specimens can be distinguished by the absence of black spots on the body. The blue catfish has three chambers in its swim bladder, while the channel catfish has two. Like the channel catfish and the lesser known Yaqui catfish of Mexico, the blue catfish has a deeply forked tail, which distinguishes these three species from the flathead and bullhead catfish, and to some extent from the white catfish, which has a moderately forked tail. Like other catfish, channel catfish have heavy, sharp thoracic and dorsal spines and long mouth spines.

Distribution

Blue cats live in the Mississippi, Missouri and Ohio river basins in the central and eastern United States, stretching north to South Dakota and south to Mexico and northern Guatemala. Dams and commercial mining are some of the factors that have affected their populations and possibly their numbers in some parts of their native range. They have been successfully introduced into some large river systems outside this range, notably the waters of the Santee-Cooper River in South Carolina. They are currently most abundant in the deep, warm waters of the South.

Habitat

Blue catfish live in rivers, streams, lakes, reservoirs and ponds, but are mainly found in large rivers and large lakes/reservoirs. They have been introduced into small lakes and ponds but rarely reach large sizes in these areas. This species prefers deep sections of large rivers, rapid flumes and waters with fast currents. Like the channel catfish, it prefers areas with good flow and a substrate of stones, gravel or sand.

Size

Blue catfish are capable of growing to gigantic sizes, but are rarely seen at their upper limit. Most anglers catch blue catfish in the 5 to 20 pound range. Fish between 20 and 50 pounds are not uncommon in good stocked waters, but blue catfish in this range are rare and specimens over this size are rare. The world record for this species is a 116lb 12oz fish caught in the Mississippi River in Arkansas in 2001. A 116-pound specimen was reportedly caught in Lake Texoma, Texas, in 1985, and a 150-pound specimen caught in the Mississippi River near St. Louis in 1879 was found locally and sent to the US National Museum. Historical sources describe 100-pound specimens at the turn of the twentieth century, and specimens weighing between 200 and 400 pounds have been reported but not documented, perhaps more as legend than probability. There is similar uncertainty about size and longevity. Several scientific reports suggest that these fish can reach 14 years of age and some reports suggest that they can live up to 21 years, but apparently longer life spans are possible for the largest specimens.

Life history and Behavior

Blue catfish spawn in spring or early summer when water temperatures are between 70° and 75°F. Nests are built by one or both parents, usually in crevices and burrows under logs and trees and in undercut banks. They often prefer secluded and dark places.

Food and feeding habits

Blue catfish seem to eat almost anything they can catch. Their diet includes various species of fish, crayfish, aquatic insects and molluscs. Herring and gizzard shad are part of their diet, especially when the catfish are larger and in areas where they are abundant. Blue catfish feed mainly on or near the bottom and are mostly nocturnal.

Reproduction

No information