Food and Agriculture Organization of the United Nations Fisheries and for a world without hunger Aquaculture Department Cultured Aquatic Species Information Programme Ictalurus punctatus (Rafinesque, 1818) I. Identity V. Status And Trends a. Biological Features VI. Main Issues b. Images Gallery a. Responsible Aquaculture Practices II. Profile VII. References a. Historical Background a. Related Links b. Main Producer Countries c. Habitat And Biology III. Production a. Production Cycle b. Production Systems c. Diseases And Control Measures IV. Statistics a. Production Statistics b. Market And Trade Identity Ictalurus punctatus Rafinesque, 1818 [Ictaluridae] FAO Names: En - Channel catfish, Fr - Barbue de rivière, Es - Bagre de canal Biological features Cylindrical body with skin lacking in scales; spots on the sides. Soft fin rays with exception of dorsal and pectoral fins which have spines. Adipose fin present. Barbels located below and at the corners of the mouth, with two barbels on the dorsal surface of the head anterior of the eyes and posterior of the snout. Deeply forked caudal fin and curved anal fin with 24-29 rays. Images gallery FAO Fisheries and Aquaculture Department Catfish pond Catfish fry Catfish raceway Wood spawning container 13-inch catfish (courtesy www.combat-fishing.com) Hatching Catfish Profile Historical background Interest in channel catfish began when the United States Fish and Fisheries Commission began stocking fish collected from the wild in the 1870s. Channel catfish were native primarily to the Mississippi River Valley but were widely introduced throughout the nation by the Commission. Spawning was first achieved in 1890 in aquaria, at which time it was learned that the male guards the eggs during incubation. Pond spawning was first observed in 1914 at a government hatchery. Spawning nests (nail kegs) were first used in 1916 and the numbers of fingerlings produced per stocked female increased. Indoor hatching of channel catfish eggs in troughs equipped with paddlewheels to move the water in a manner that simulates the fanning of the eggs by the male fish was first accomplished in 1929. Commercial aquaculture was first considered to be economically practical in the late 1950s. Catfish farming developed rapidly during the 1960s and 1970s as improvements in pond management, disease identification and control, and prepared feeds were developed and adopted by farmers. The commercial industry developed FAO Fisheries and Aquaculture Department in the southern United States within the original range of the species. At least 90 percent of the farmed fish are produced in the Mississippi River Valley region. Main producer countries Channel catfish have been introduced into Europe, Russian Federation, Cuba and portions of Latin America. The primary interest in many countries appears to be recreational fishing. Main producer countries of Ictalurus punctatus (FAO Fishery Statistics, 2006) Habitat and biology Channel catfish are native to flowing waters in temperate environments within North America, including southern Canada and northern Mexico. Adults first spawn at two or three years of age. Spawning in nature occurs in the spring, beginning in about March in the southern part of the range and later as latitude increases. Eggs are often deposited under fallen logs or in some type of natural depression. The eggs are laid in an adhesive mass. Females of 0.5-1.8 kg produce an average of 8 800 eggs/kg of body weight, with larger females producing an average of 6 600 eggs/kg. Once egg laying and fertilization are complete, the male will chase the female from the nesting area and tend to the eggs by fanning the mass with his fins to keep oxygenated water moving over them. Depending on temperature, the eggs will hatch within 5-10 days and the male will continue to guard the sac fry for several days until the yolk sacs are absorbed and the fry are able to swim about in search of food. Channel catfish are known as opportunistic omnivores in that they will feed upon a wide variety of plant and animal matter; that is, virtually anything that is available. Production Production cycle FAO Fisheries and Aquaculture Department Production cycle of Ictalurus punctatus Production systems Channel catfish are reared in ponds, cages, and circular tanks or linear raceways in both the United States and China. Monoculture dominates in the U.S., while both monoculture and polyculture with traditional species such as carp occurs in China. Formulated feeds are employed in both nations. The details presented below refer to channel catfish culture in the United States of America. Seed supply The majority of channel catfish are grown in ponds. Spawning occurs in the spring and may be conducted in open ponds where adults are stocked at a density ranging from 60-325/ha in ratios ranging from 1:1 to 1:4 (male:female) and allowed to select their own mates. Alternatively, adults may be paired in pens within a spawning pond. In both instances nests comprised of metal cans, drain tiles, wooden boxes or other types of enclosures of appropriate size are utilized. Eggs may be allowed to hatch within the spawning pond. In that case, after the spawning season the adults are typically removed to another pond. More commonly, the nests are inspected at three or four day intervals and any egg masses found are collected and taken to a hatchery, where the eggs are incubated in troughs or raceways and the fry are maintained until they swim to the water surface in search of food. Fry are often fed finely ground prepared feed for several days prior to being stocked in fingerling ponds where they are reared for several months (often throughout the first year of life). Some farmers specialize in selling fry or fingerlings to producers of market-sized fish, while others purchase fingerlings for grow-out; however, many farmers operate their own hatcheries and grow-out operations. Ongrowing techniques Ponds Once the fingerlings are several centimetres long, they can be stocked into grow-out ponds. The traditional approach was to stock a given number of fish per hectare, grow them until the autumn of the second year of FAO Fisheries and Aquaculture Department life, drain the pond, and harvest the fish for marketing. Since nearly all the fish produced under that system reached the market over a limited period of time, the flow of product to the market was not conducive to having fresh product available year round. Also, glutting of the market during the fall led to depressed prices to producers. Today, an intermittent harvesting approach is employed. Ponds are partially harvested every several weeks to a few months and marketable fish are removed. The appropriate number of fingerlings is then stocked to replace the fish removed. Thus, various fish sizes are in the pond at the same time. The process can be maintained for several years, during which time the ponds are not drained. Fingerling ponds are often fertilized, usually with inorganic fertilizer, in advance of stocking to induce the development of plankton blooms. Prepared feed fines, and later crumbles, then standard feed pellets (about 6 mm diameter) are provided. The feeding rate may be as high as 50 percent of estimated fish body weight daily at first feeding but is gradually reduced as the fish grow. Once the fish are a few centimetres long they are fed at 3-4 percent of body weight daily during the growing season. The feeding level is reduced and feed may even be withheld completely during winter months. Water quality management is critical to pond catfish production. High stocking densities, particularly during summer, can lead to stress, disease, and mortality due to deterioration in water quality, particularly low dissolved oxygen. During critical periods ponds are monitored and emergency aeration is provided when necessary to maintain dissolved oxygen levels within an acceptable range (typically >3.0 mg/litre). Tanks and Raceways Channel catfish are sometimes reared in flow-through tanks or raceways, indoors or outdoors. Recirculating system culture has been attempted over the years but few, if any, economically successful farms have been developed. Flow-through raceway and tank culture depends upon a suitable supply of water of the proper temperature (ideally 26-30 °C) for grow-out. Such water temperatures can be obtained from surface waters in the southern United States, from geothermal waters in various parts of the nation, and from co-generation or electric power generating plants. Production of catfish in such systems represents a small fraction of the annual total. The other aspects of tank and raceway culture are similar to those associated with pond culture with the exception that much less land is required, though water quantities (and thus costs) incurred may be far in excess of those associated with pond culture. Cages Historically, there has been some interest in rearing channel catfish in cages placed in streams, lakes or reservoirs. While some facilities of that type could still be in operation, their contribution to total catfish production is insignificant. Other than the type of culture chambers used, cage culture practices would be similar to those used by pond and tank culturists. Feed supply The prepared feeds referred to above consist of various combinations of such plant proteins such as soybean meal, cottonseed meal, corn meal, peanut (groundnut) meal, and wheat, supplemented with vegetable oil, vitamins, and minerals. Very little, if any animal protein (e.g. fish meal) is currently employed in grow-out feeds for channel catfish. National and international feed companies provide feeds formulated specifically for catfish, as do many local feed mills in regions where catfish culture is concentrated. The feeds used in tanks and raceways may be supplemented with excess levels of vitamins, since natural foods that can supply those nutrients may not be available, particularly with regard to indoor systems (other than greenhouses).