Catfish (Hito) Raising

Clarias batrachus is a black, slippery fish with mustache to aid it in swimming. It is called catfish in English, hito in Ilocos, ito in Pampanga, and pantat in Pangasinan, Cebu and Iloilo. Catfish are usually found in marshes, ricefields, swamps, streams, rivers, lakes irrigation canals, or in any body or fresh water.

Catfish farming requires extremely heavy stocking (75 to 100 fingerlings per square meter) and intensive feeding (90 per cent protein). Hito fry supplies are few; thus, those who go into catfish raising depend on natural sources for fry. But with proper planning and management, the hito farmers can produce his own supply of fries.

The size of the ponds depends on your available capital. The minimum size is 50 square meter (sq m) and should be located in low and flat areas. Land where pesticides have been regularly used should be avoided. Choose a shady area so that fish will have shade when the sun is intense and lumot or moss will grow easily. The area should also have a good supply of water either from wells, spring or run-off ponds.

There are two ways to prepare your ponds. The dug-out excavated type is made by digging the soil of the desired area at least one to one-and-a-half (1 1/2) meters (m) deep. The soil removed is used to build perimeter dikes 2 m high from the base to the top. The inner sides of the ponds is made firm by pressing with a heavy log or board. This will prevent the catfish from climbing or burrowing through the sides. A water pipe, 7.62 centimeters (cm) in diameter should be installed in the middle of the ponds so water can run through it slowly. This aerates the pond water and discourages the catfish from digging and stirring the pond bottom.

The dug-out concrete type also follows the same principle, except that the walling is made of 10 cm x 20 cm x 41 x cm concrete hallow blocks. The bottom is covered with a 15 cm-thick layer of clay soil and planted with aquatic plants like tapo grass, water lily, or kangkong to create the natural habitat for the fish.

Stocking rate. The extremely heavy stocking method produces a minimum poundage of fish per unit area. Catfish farming produces 2 crops a year at an average rearing period of 5 to 6 months. It is best to stock in the late afternoon or early morning when it is cool.

The stocking rate depends on size of fish and depth of water. (See figures below.)

Size of fish | #of Fish | stock/sqm surface | period (months)
3 to 4 cm | 60 pcs/kg | 80 to 100 | 5 to 6
5 to 6 cm | 50 pcs/kg | 60 to 80 | 4 to 5
7 to 10 cm | 30 pcs/kg | 40 to 60 | 3 to 4

Feeding. Catfish are carnivorous so their feed is 90 per cent meat or other protein sources. These can be ground fresh trash fish, worms, insects, slaughterhouse by-products, chicken entrails, dried or fresh water shrimp, fish of fall and by-products of canning factories. The remaining 10 per cent is composed of boiled broken rice mixed with vegetables or rice bran. To augment food supply, install strong light over pond to attract insects.

Feed the catfish twice a day. To avoid waste, give the feeds slowly, by handful, until the fish stop eating. Daily feed ration is 6-7 per cent of the fish stock’s body weight. If the fish remains small after giving them the necessary feed, provide them with 30 kilograms of farmyard manure.

Add 5 to 10 per cent carbohydrates in the feed to enhance the stock growth rate. Trash feed should be fresh to maintain the nutritive value. Never overfeed since the excess would only pollute the water causing death or stunted growth.

Mating and spawning. Female catfish ready to spawn or to produce offspring when it build its nest of debris or roots of aquatic plants like water hyacinths, kangkong, or filamentous algae. It spawns in shallow water, 30 cm to 60 cm deep.

Male and female catfish starts courting by chasing each other, darting sideways, pressing their abdominal regions together. This constantly movement is repeated several times until the females releases the eggs and male milt or sperms is simultaneously ejaculated. Fertilization takes place at 27^o to 30^oC water temperature.

The number of eggs laid range from a few hundreds to several thousands.

Never scrimp on feeds especially during this period, remember that catfish are cannibalistic and quarrelsome. If the parent fish are very hungry, they may gobble up the young as quickly as any other food that come their way.

One drawback that discourages people from catfish farming is the lack of fingerlings. The following process will assure you a continuous supply of fingerlings.

The two methods effecting spawning is by hormone injection. Both methods use the most gravid or pregnant females and healthy. mature males, each weighing at least 200 grams (g).

The body of the pregnant hito is distended prominently, the genital part pinkies, and the blood vessels on its belly prominent. Breeders should be conditioned first in the concrete or semi-concrete tanks/vats 2 to 5 months before they are injected with hormone.

The natural method entails injecting hormones to gravid females and male catfish through their coal regions or bases located on the posterior side of the pelvic fin. Use commercial hormone preparation like gonadotropin or synahorin. If these preparations are not available, use fresh of fish. Each female hito should be receive 200 to 250 IU (international units) of gonadotropin, while each male, 50 IU. Wrap fish in a small net so they will not struggle during injection. After injection, put the male and female together in an oxygenated tank provided with an improvised fish nest made of cabo negro(blank palm fibers).

The stripping method requires several male catfish milters to be killed. Use forceps to remove their testes which is pinkish yellow and soak in Ringer’s solution. Extract sperm by macerating the testes in the distilled water. Use sperm to fertilize breeder’s eggs. Inject hormone (mentioned earlier) into the gravidbreeder’s body. Inject at the side of the fish’s body, a little above lateral line, with this dosage: gonadotropin = 750 to 1,500 IU; synahorin = 1,000 to 1,500 IU. After 12 hours, squeeze the breeder’s abdomen to force the eggs out. A 250-gram breeder produces 8,000 to 15,000 eggs. Mix eggs with sperm and stir for a minute. Spread eggs thinly over hatching troughs which are immersed in running water with a temperature of 26^o to 36^oC. Eggs will hatch 24 to 36 hours later.

Transfer the hatch larvae in basins half-filled with water. The young fish will absorb all the egg yolk in 5 days. After this period, they will begin to swim active and take food.

You can rear 15,000 to 20,000 fries in a space of 1 x 3 x 6 m. Minute organisms are the best food for the fry at the early stage. Twenty thousand (20,000) fry needs 20,000 liters (1) of zooplankton every morning plus a kilo of fish flesh and 250 g of peanut cake in the afternoon. After one week, fry should have grown to 1.5-4.3 cm long.

Pond-raised catfish are usually attacked by bacterial diseases. Aeromonas spp. is characterized by distended abdomen filled with opaque or bloody fluid, red spots on the body, stomach filled with yellow mucus, swollen kidneys, eroded fins, inflamed mouth, pale or green liver and excess secret of mucus. When catfish lose their equilibrium, are pale, their abdominal area tight with a distended anterior, and their peritoneal cavity filled with bloody excretion , they are suffering from pseudomonas spp. The usual sources are diseased fishes and frogs. Therefore, preventive measure must be taken during transporting and before stocking the fish. One method is to add penicillin and streptomycin to the water at the rate of 10 to 50 milligrams of per liter.

Harvesting. The rearing period depends upon the size of fingerlings stocked. Seven to ten cm fingerlings culture period lasts about 4 months while 3 to 4 cm fingerlings need 6 months. When the fish are about 20 to 25 cm long you can start harvesting, partially or completely. Drain pond partially and captured fish by seines (net hung vertically, one side with floats, other side with sinkers) or scoop nets as soon as water level is low enough. To harvest completely, let the water out through the drain pipe.

Storage and transport. The quality of fish depends on handling from the time it is caught until it reaches the consumer. Wash fish to remove mud, debris, or any foreign substance, sort them according to size and separate those which are bruised decomposed or damaged.

Remove harvested catfish from water immediately after catch and place in wood, plastic aluminum, or styroform containers. Be sure that the containers have perforated covers to prevent hito from escaping.

Catfish are equipped with special assessor organs which enable them to survive out of water for a long time. There are no rules to be followed in storing an d transporting hito because of their innate hardiness. Fill three-fourth of the container with 20 to 25 cm long catfish and four a liter of plain water. This moisture level will enable them to withstand the rigors of travel up to 12 hours. By following this, the harvest will reach markets in tip-top condition where they are sold live. This manner of transport is also used for foreign destinations.

Source: dost.gov.ph