CHANNEL CATFISH CULTURE

Channel Catfish ( Ictalurus punctatus ) The scientific name for the channel catfish is Ictalurus punctatus. The channel catfish is distinguished from other native catfishes by its black spots and forked tail.

Native Range of Channel Catfish in the United States The channel catfish is native to the Mississippi drainage basin from Canada to Mexico and the southeastern Gulf Coast and Florida. The channel catfish has been introduced to most states in the continental United States.

Food Habits Channel catfish are omnivorous, eating a wide range of fishes, crustaceans and benthic insect larvae. As the channel catfish grows larger, its diet becomes more piscivorous. Channel catfish over 1 kg eat fish and crustaceans almost exclusively.

Preferred Habitat Reservoirs and lakes Rivers Channel catfish live in a wide variety of habitats from fast flowing rivers and stagnant water reservoirs and lakes. Reservoirs and lakes Rivers

Reproductive Live History 1. Sexual maturity is reached in 2 to 3 years in the southeastern U. S. 2. Spawning takes place in a cavity formed by rocks, logs or a hole in a lake or river bank. 3. Preferred spawning water temperatures: 21-29 C, with optimal temperature 24 to 26 C. Channel catfish reach sexual maturity in 2 to 3 years in the Southeastern U. S. Fish of at least 3 years of age are preferred by farmers as brood fish. Channel catfish living in northern climates may reach sexual maturity in 4 to 5 years. Spawning begins when water temperatures remain above 21oC for 24 hours. Preferred water temperature for spawning is 24 to 26oC in the southern U. S.. Males seek a spawning cavity to defend. The dark cavity can be among and under rocks and logs or a hole under or in a lake or river bank.

Sexual behavior Spawning cavity 1. Males defend a territory/cavity. 2. Female enters the cavity and spawns. 3. Males incubate eggs and defend fry. 4. Males can spawn with more than one female a season. A female is attracted to the cavity and after a short courtship, will spawn. The male chases the female away after spawning and he will defend the eggs and recently hatched fry. After the fry leave the spawning cavity to feed on their own, the male will often mate with another female. Spawning cavity

Catfish are grown in 4 to 10 ha earthen ponds with flat bottoms. A typical catfish farm will have 40 to 80 ha of water surface. Some catfish farms have over 400 ha of water surface. Ponds area varies between 1 ha and 10 ha but the preferred pond area is 4 to 5 ha. Fish pond soils should have enough clay to retain water and limit seepage through the bottom pond. Most catfish ponds are constructed by building 4 dikes or levees to retain the water. Ponds with 4 sides are called levee ponds. Some catfish ponds have only one dike constructed. Ponds with one dike are call hillside ponds. The dike is constructed across a valley to capture rainfall as it flows from the drainage basin. All catfish ponds have a smooth, flat bottom sloped toward a drain pipe to allow complete water removal. Pond bottoms are flat and free of obstructions to permit fish harvest with a seine net. Ideally, average water depth is 1.3 meters and maximum depth is 2 meters. Catfish are grown in 4 to 10 ha earthen ponds with flat bottoms.

Catfish ponds are filled with either: Filtered surface water or rainfall Well water Most catfish ponds are filled with water pumped from shallow wells. Well water is normally free of toxic contaminants and wild fish that can introduce diseases to the catfish and compete for feed. Some ponds may be filled with surface water pumped from rivers and streams. Surface water should be filtered to eliminate wild fishes. Hillside ponds are normally filled with rainwater captured as it flows off the drainage basin. Pumped water is expensive but available on demand. Rainfall is cheap but is often not available when needed.

Spawning in captivity: 1. Stock adults 3 to 8 years old 2. Stock 1 male to 2 females 3. Stock 800 kg of brooders/ha male Channel catfish spawn naturally in captivity without the hormone injections to induce the release of sexual products. Brood fish should be at least 3 years old. Brood fish older than 8 years old are poor spawners and too large to handle easily. Brood fish can be raised in captivity. During the spawning season, females will have a swollen belly. Males become dark in color and have a head that is much wider and more muscular than the females. Stocking density should not exceed 1,000 kg/ha to assure that water quality in brood fish holding ponds remains good. Brood fish are transferred from holding ponds into freshly filled spawning ponds in the Spring before water temperatures reach spawning temperatures. The ratio of males to females stocked is 1 to 2. Brood fish are stocked at approximately 800 kg/ha. When water temperatures remain above 21oC for 24 hours and maximum temperature is 24 to 26oC, spawning containers are placed in the ponds. One container per male is used and the containers are marked so they are easily found when checking for eggs. female

Spawning Containers float Ammo cans Milk cans Wooden box Boxes in spawning pond Ammunition cans, milk cans, wooden boxes and plastic buckets are some of the containers used to spawn channel catfish. The containers should be large enough to allow a pair of adult catfish to enter. The container entrance should be just large enough to permit a brood catfish to enter. The walls of the container should be opaque so the inside of the container is dark. The containers are placed at a water depth of 1 meter with the entrance pointed toward the center of the pond. The containers should be firmly attached to the pond bottom and marked so they can be easily found.

Spawning occurs during May and June in the Southeastern U. S Spawning occurs during May and June in the Southeastern U. S. Spawning cans are checked every 2 to 3 days for spawns. Spawning containers are checked for eggs every 2 to 3 days. Channel catfish eggs are adhesive and form a mass that is easily handled with care. The eggs are removed from the spawning container and transferred to incubators located in a hatchery. Females spawn about 5,000 eggs/kg of body weight.

Eggs are transported to a hatching shed. Channel catfish eggs are transferred to incubators located in a hatching shed or building. The hatchery building is often a simple, low cost structure used only to hatch eggs and care for young fry. Eggs are transported to a hatching shed.

Eggs are placed in metal wire baskets suspended in hatching troughs Eggs are placed in metal wire baskets suspended in hatching troughs. Troughs are made of wood, fiberglass, metal and hard plastic. Paddles powered by electric motors rotate at 30 RPM to softly agitate the eggs and assure that they are well oxygenated. Clean water with a temperature of 24 to 26oC flows into the troughs constantly to maintain good water quality. Eggs are placed in 5-mm square wire mesh baskets suspended in a paddlewheel incubator.

Eggs hatch in 5 to 6 days at water temperatures of 24 to 26 °C. Eggs hatch in 5 to 6 day depending on water temperature. Hatchlings fall through the wire mesh baskets to the floor of the incubation trough. Hatchlings, or yolk-sac fry, are easily collected, counted and transferred to nursery facilities.

Fry are fed powdered feed. Fry are placed in screen boxes or troughs for 7 to 14 days before stocking in ponds. Fry are fed powdered feed. After 4 to 5 days, the fry swim to the water surface looking for food. At this time, fry are fed a high quality powdered feed several times a day. When the fry reach about 2.5 cm they are counted and transferred to recently filled and fertilized nursery ponds. Screen bottom boxes Fiberglass trough

Fry are stocked at 150,000 to 250,000/ha and grown for 5 months. Fry are stocked into nursery ponds at 150,000 to 250,000/ha. Stocking density depends on the preferred final harvest size. Fry stocked at a high density will be smaller at harvest than fry stocked at a low density.

Fry are fed powdered, crumbled and pelleted feeds. Initially, fry are fed with a powdered feed but as they grow, particle size is increased until they are able to consume a small diameter floating pellet. Fingerlings are fed twice daily and water quality is monitored constantly to assure a healthy environment.

Fry stocked in June will reach 10 to 15 cm channel catfish fingerlings by November. Fingerlings are transferred to fattening ponds during January to April when water temperatures are still cold to reduce handling stress. Stocking density is 15,000 to 20,000/ha. Fingerlings are stocked in fattening ponds during January to March. Stocking density is 15,000 to 20,000/ha.

Catfish feed is purchased by the bag or delivered in bulk and stored in silos. Pelleted feed is purchase in bulk by large farmers and by the bag by small farmers. Feed is cheaper when purchased in bulk. Each truck pictured above carries 5,500 kg of feed. Bulk feed is stored in silos near the ponds.

Floating pellets are distributed by a feed blower mounted on a truck. Catfish feeds contain 90% grains and grain by-products and 10% animal by-products such as fish meal and meat and bone meal. Catfish farmers purchase floating diets which permit observation of fish feed behavior. Feeds are blown into the ponds from a container mounted on a trailer or truck. corn wheat soybean

Feed amount is controlled by an electronic scale located in the truck cab. Catfish are fed what they will eat up to a maximum of 120 kg/ha/day. Feed is blown into the ponds as the truck drives along the pond dikes. The weight of feed placed in each pond is controlled by an electronic scale controlled in the truck cab. The feed container is placed on a scale that weighs the decrease in weight as the feed is distributed. A predetermined weight of feed is placed in each pond. When the feed in the container decreases by the amount to be fed, the door to the container is automatically closed and feeding stops. One man can feed 100 ha per day. Channel catfish in ponds with aeration are fed up to 120 kg/ha/day to assure that water quality is maintained at a level that will permit fish at grow rapidly and remain healthy. Ponds that receive more than 120 kg/ha/day are subject to low dissolved oxygen and poor fish health. Catfish ponds without aeration should not receive more than 40 kg/ha/day to maintain adequate concentrations of dissolved oxygen in the water.

Dissolved oxygen concentration is checked night and day to assure that levels remain above 2 mg/l. Ponds receiving feeds have fertile waters, causing heavy phytoplankton concentrations or “ blooms”. Excess phytoplankton can cause dissolved oxygen to drop to critical levels at night when oxygen is not replenished by photosynthesis. Dissolved oxygen below 2 mg/l ( 2ppm ) can cause catfish to stop feeding and levels below 1 mg/l can cause mortality. Pond waters are monitored constantly, especially at night, to assure that adequate aeration is available to maintain pond waters above 2 mg/l of dissolved oxygen. Large catfish farms will have labor that works all night measuring dissolve oxygen. Ammonia and nitrite can also cause fish mortality and must be closely monitored.

Electric (fixed) and tractor (mobile) powered paddlewheels are used to increase D. O. levels. Dissolved oxygen concentration is maintained above 2 mg/l with paddlewheel aerators. Paddlewheel aerators are powered by electricity or by tractors. Aerators attached to tractors are mobile, so they are placed where needed. Paddlewheels powered by electricity are fixed in each pond and normally not moved from pond to pond as needed. Five to 7.5 hp/ha of fixed paddlewheel aeration is used to maintain dissolved oxygen under most circumstances. Sometimes, mobile aerators are needed in addition to fixed aerators during an emergency. Water exchange is not used in channel catfish ponds to improve water quality because of the high cost of pumping water and the large water volume needed to exchange water in large ponds. No water exchange is practiced because ponds are large and pumping water is costly.

Low D. O. can kill catfish within 1 or 2 hours. Dissolved oxygen below 1 mg/l ( 1ppm ) can kill channel catfish in 1 or 2 hours. Mortality due to low dissolved oxygen usually happens at night when oxygen released to the water by photosynthesis has stopped but fish and plants are still respiring.

Many diseases cause fish mortality. Often, low dissolved oxygen will stress the catfish and cause diseases that kill the fish days after the low oxygen event. Maintaining good water quality is the best way to reduce catfish diseases. Many diseases cause fish mortality.

Birds consume many fish in some regions. Shoo ! Aquatic birds prey on catfish and cause considerable economic losses to farmers. Herons, cormorants and pelicans are the most serious bird predators. Many scare devises are used with limited success to reduce bird predation. Gas cannon to scare the birds

Catfish are harvested when they reach 500 to 1000 g after 12 to 18 months of growth in fattening ponds. Seine nets are used to capture the fish. Seines are commonly 130 to 250 m long and are stored on hydraulically powered reels. The reels are used to distribute and pull the seines. A second tractor also helps to pull the seine. The size of the seine mesh controls the size of fish harvested. Catfish too small for harvest remain in the pond for additional growth. Catfish are removed from the pond with a seine stored on a hydraulic reel powered by a tractor.

Management systems used: Monoharvest All catfish are removed from the pond when they reach 0.5 to 1.0 kg, 6 to 12 months from stocking. Ponds are drained yearly. 2. Multi-harvest Only catfish larger than 0.5 kg are removed by partial seine harvest. Ponds are restocked yearly with small catfish. Large and small catfish are in the pond together. Ponds are partial harvested 2 to 3 times per year. Ponds are drained every 5 to 8 years. Mono- and multi-harvest management systems are used to grow catfish. The multi-harvest system is the most popular because it conserves water and reduces pumping cost, effluent release to natural waters is low and income is available throughout the year to pay expenses as fish are harvested from ponds several times a year.

Catfish are captured in the afternoon or night and held in live cars ( cages ) overnight. Catfish too small for harvest swim through the cage wall and remain in the pond. Aerated water is pushed through the cage of fish to assure that dissolved oxygen remains high. Early the next morning, trucks from the processing plant arrive and fish are loaded into transport tanks with large baskets. Catfish are concentrated in the cages for easy loading by pulling the cage over a flat bottom boat to reduce the cage volume. Catfish are retained in a holding net overnight to eliminate small catfish. Fish are crowded for loading onto the transport truck. A crew of 5 can load 15,000 kg of fish in 1 hour.

Catfish are weighed onto trucks taking the fish to the processing factory. Each basket holds 900 kg of fish. scale Catfish are transported live to the processing plant in tanks with water and aeration. A truck mounted mechanical arm is used to load baskets of fish onto the truck. The fish are weighed onto the trucks. A crew of 5 can load 7,500 kg of fish in 30 minutes. Most ponds are harvested by crews employed by the processing plants. Large farms may prefer to use their own labor to harvest fish or contract harvest crews. Transport trucks are supplied by the processors.

Fish are checked for off-flavor 2 weeks, 1 day and upon arrival at the processor. Off-flavor fish are not harvested. The fish are taste tested before harvest to assure that the flesh has no bad odors or flavors. Catfish are tested 2 weeks and 1 day before harvest by the processor to assure flesh quality. Catfish that have poor tasting flesh are not harvested and will remain in the pond until the bad taste has disappeared from the flesh. Off-flavor is usually caused by certain types of phytoplankton found in the fish ponds.

Catfish are weighed a second time upon arrival at the processor Catfish are weighed a second time upon arrival at the processor. Fish arrive alive. scale Fish arrive live at the processor to help assure flesh quality. Catfish are weighed a second time to confirm the fish weight noted by the farmers during harvest.

Catfish are cleaned, filleted and frozen by the processor. Catfish are cleaned by removing the head, skin and viscera with machines. Fillets are removed by machine and trimmed manually. Large mechanized plants will process 100,000 kg of whole catfish per day. Small plants that manually clean catfish may process only 100 to 500 kg per day. From the time the live catfish enter the plant to the frozen end product is less than 2 hours.

Processed forms as a percentage of total catfish processed: whole Processed forms as a percentage of total catfish processed: steaks 1. Whole - 20 % 2. Pieces and bellies - 20% 3. Fillets - 60 % Preservation method as a percentage of total catfish processed: 1. iced - 20 % 2. frozen - 80 % strips Catfish are processed into 4 forms as illustrated above. Headed and gutted whole catfish are 20% of processed catfish, pieces and bellies ( strips, nuggets and steaks ) are another 20% and fillets are 60%. Approximately 40% of whole body weight is fillet. Heads, viscera, skin and carcasses are sold at little or no cost to rendering plants that make meat and bone meal. Twenty percent of all processed forms are sold fresh, on ice and 80% are sold frozen. Fillets and nuggets

The catfish industry maintains a quality control program to insure the consumer a fresh and healthy product. Catfish farmers and industry representatives paid by the farmers and processors promote quality control in the catfish farming industry. Quality control includes proper use of chemicals to control phytoplankton and diseases, use of high quality feed ingredients and testing to insure the freshness, flavor and sanitation of the processed catfish. Farmers and processors want to assure the consumer that farm raised catfish is a high quality and healthy product.

Principle farming states are located in the Southeastern U. S Principle farming states are located in the Southeastern U. S.. Mississippi (MS) Alabama (AL) and Arkansas (AR) produce 90 % of the farmed catfish. Mississippi is the leading producer of farm raised catfish in the United States. Alabama and Arkansas harvest 15 and 10% of U. S. farmed catfish, respectively, and together with Mississippi raised 90% of the catfish harvested in the U. S.. Mississippi accounts for 65 % of farmed catfish

The channel catfish industry developed in the Southeast because: 1. Popular food fish - market 2. Warm climate 3. Abundant water and clay soils Catfish is a traditional food in the southeastern U. S. Catfish were captured from rivers and reservoirs by commercial and recreational fishers. Consumers in the southeast were eager to purchase farm raised catfish. Farmers that grew channel catfish in the early years found a ready market for their fish crop. However, consumers in regions outside the southeast considered catfish undesirable and would not buy it. Catfish farmers financed national marketing campaigns in newspapers, magazines and on the radio to convince consumers to try catfish. Slowly, the market for catfish expanded and today, most large supermarkets in the U. S. carry catfish in their seafood sections. Less than 1% of the channel catfish crop is exported and sold outside the U. S. The warm humid climate is one of the best in the U. S. for farming fish in ponds. The growing season for catfish in the southeast is 200 to 240 days and water to fill ponds is abundant. Soybeans and corn are the principal ingredients in fish feeds. Major corn and soybean growing regions are in the Midwest and Southeast along the Mississippi River and its major tributaries. Grains are transported cheaply by barge on the Mississippi River system to the southeast where they are made into fish feeds. 4. Close to major grain farming regions - cheap fish feeds

Pond yield 4,000 to 7,000 kg/ha/year The average yearly yield of channel catfish is 4,000 to 7,000 kg/ha/year. The weight of catfish harvested yearly will depend on the length of the growing season, the culture system used and the skill of the farmer.

Channel Catfish Growth in Live Weight Processed and Average Price per Kilogram, 1970 - 2002   YEAR LIVE WEIGHT AVG. PRICE* PROCESSED, KG PER KG, $US. ------- --------------------- ----------------- 1970 2,609,545 0.75 1975 7,336,363 1.09 1980 21,120,000 1.50 1985 87,098,181 1.58 163,636,360 1.69 203,130,000 1.74 1999 271,194,000 1.63 269,819,540 1.65 271,141,272 1.43 2002 286,636,810 1.25 * Price to farmer for fish delivered to the processing plant Live weight of channel catfish processed has grown by about 10% per year from 1970 until 1999. However, in 2000 and 2001 live weight of catfish processed did not increase from 1999. The weight of catfish processed in 2002 reached an all time high. However, the prices paid to farmers for live catfish declined drastically in 2001 and 2002 due to a worsening U. S. economy and competition from imported catfish. Consumer demand for catfish is expected to grow and expansion of pond area for growing catfish should increase. Catfish farming is the most valuable aquaculture activity in the United States.

Channel catfish has a firm, white flesh that is appealing to consumers Channel catfish has a firm, white flesh that is appealing to consumers. Catfish can be fried, grilled, blacked, broiled, steamed, microwaved and stewed depending on consumer preference. Supply and price of channel catfish is consistent and consumers are assured of a healthy, nutritional, flavorful product. EAT MORE CATFISH

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