Latin name

Ictalurus punctatus

Other names

Сatfish, river catfish, fiddler, blue channel catfish, Great Lakes catfish, willow catfish, spotted catfish, forked-tail catfish, lady catfish.

Identification

The body is bare, elongated, slender and compressed at the rear. The caudal fin is long and deeply emarginated. The dorsal fin is high with a long spike. The adipose fin is located above the posterior part of the elongated anal fin, rounded at the lower edge. Pectoral fins with a strong serrated spike. Head small, conical, mouth small, terminal, with elongated upper jaw. Four pairs of whiskers. Antennas long, maxillary, reaching or passing behind the gill cover. Channel catfish can often be recognised at a glance by their deeply forked tail and small irregular spots on their flanks. The spots may not be present on all specimens, but they are usually noticeable on smaller specimens. These pigmented spots are most visible on juveniles and less visible on older fish. The blue catfish also has a forked tail, but without spots, as does the Yaqui catfish (Ictalurus pricei; a species native to the Yaqui River in Mexico). The channel catfish is more slender than other catfish, possibly due to its river origin, and has a relatively small head. It differs from the white and blue catfish in having 24 to 29 anal fin rays. The body of the channel catfish is pale blue to pale olive with a slight silvery tinge, but the colour varies according to habitat and water conditions. Male channel catfish can be completely black during the spawning season, while others can be dark blue with or without small spots, or uniformly light blue or silver like the blue or white catfish. Another feature that distinguishes the channel catfish from the blue catfish is the anal fin. The channel catfish has a shorter and more rounded fin than the blue catfish. Like other catfish, the channel catfish has heavy, sharp thoracic and dorsal spines and long mouth spines.

Distribution

Channel cats inhabit freshwater habitats throughout much of the United States, as well as southern Canada and northeastern Mexico. In the United States, they are most common in the central region east of the Appalachian Mountains and less common on the west and east coasts, where they have been largely introduced.

Habitat

The channel catfish lives in rivers, streams, lakes, reservoirs and ponds. Of all the catfish, the channel catfish prefers clean flowing water the most, although it will do equally well in lakes and ponds. In large lakes and rivers it prefers clean bottoms with sand, gravel or shingle. It does not tolerate some currents and is more likely to be found in warm, still, slow-moving areas. Juveniles stay in shallow water, usually in the current, and find shelter among rocks. Adults are found at greater depths in pools, near steep banks, long crevices or other rocky outcrops. However, this species does not require good water quality and can live in muddy lakes and ponds as well as standing water. It tolerates temperature increases of up to 40°C and decreases in oxygen concentrations of up to 3 mg/l.

Size

The maximum age of these fish varies with latitude. Some fishing sources report a maximum life span of 15 to 20 years, although it is believed that they can live for more than 20 years. Commonly caught specimens weigh between 1 and 7 pounds. Fish weighing more than 15 pounds are uncommon, while a 20-pound specimen is considered very large. The world record specimen caught with all tackle in 1964 weighed 58 pounds. The highest rate of growth occurs in the first year of life, when the length reaches 8 cm. Average annual growth is between 17 and 53 mm. At 9 years of age it is usually 40 cm long and at 17 years of age 60 cm. With rapid growth, it matures at the age of 3 years with a length of 38-40.5 cm and a weight of 0.7 kg. With slow growth, maturity is delayed until 4 or 5 years of age, when it reaches a length of 28-30.5 cm.

Life history and Behavior

Channel catfish spawn in spring or early summer when water temperatures are between 70° and 85°F. Nests are built by one or both parents, sometimes on the open bottom but more often in crevices and holes under logs and trees and in undercut banks. They often prefer sheltered and dark places. The male guards the eggs, aerates them and is reported to eat some of the eggs during incubation, although he guards the young until they disperse. Ten-inch females can lay only 2,000 eggs, while fish over 30 inches long can lay 20,000 eggs.

Food and feeding habits

Channel catfish feed mainly on insects, crayfish, molluscs and various fish. Less common are higher plants, algae and detritus. Larger fish of about 42 cm or more in length will eat the catfish. Catfish eat both live prey and the remains of various animals, relying mainly on their sense of taste and smell to find food.

Reproduction

In Kansas waters it spawns in late May or June. Spawning sites are always located in depressions or crevices along the banks, under rock outcrops in channels, and between snags and logs stuck on or under the river bottom. Males select a nest site, enlarge the area by removing soft sediment from the bottom, and remain near their nest throughout the spawning season. Females enter the nest only to lay eggs. In artificial breeding, an average of 6790 eggs have been obtained from females weighing 1.03-1.78 kg at the age of 4-6 years after three hypophysial injections. In ponds it can spawn in wooden boxes, ceramic tubes, metal cylinders or milk cans. The pale yellow eggs released by the female are spherical and 3.0-3.5 mm in diameter. The larvae hatch about 7 days after oviposition, the fry swarm in or near the nest for a few days, at about 4 days the fry begin to rise to the surface of the water and at about 6 days old they move completely to external feeding and gradually spread out into shallow channels where they remain until winter.