Catfish has a handsome body, long and elegant whiskers, and graceful swimming posture in the water. But how to raise catfish? The following is the catfish breeding method I compiled, I hope it is useful to you.
Catfish breeding methods
Seed cultivation
The whole process of catfish seed cultivation can be roughly divided into four stages:
1. Feeding-free period: The fry have just emerged from the membrane and are about 0.7-0.8 cm in length. At this time, the yolk sacs of the fry have not disappeared. The fry are clustered in the corners of the bottom of the pond, trembling slightly, and the fish are greenish-yellow. Only a few fry leave the bottom of the pond and swim aimlessly. Their ability to move toward darkness is weak. The fry rely on absorbing the yolk sac. Nutrients grow and develop without feeding feed. After 2-6 days of development, the nutrients in the yolk sac of the fry are gradually absorbed, the yolk sac disappears, the distribution area of ??the fish school increases, and the fish school appears blue and black. Some fry begin to swim away from the bottom of Shantou to feed, and their ability to move when it becomes dark becomes worse. Strong, appropriate amount and palatable feed should be fed in time at this time. Mastering the opening and feeding time of fry is one of the key links in the success or failure of fry raising.
Based on experience, the time from hatching to the disappearance of the yolk sac is closely related to the temperature: 17-18°C takes 6 days, 19-20°C takes 5 days, and 21- It takes 4 days for 23℃, 3 days for 24-26℃, and 2 days for water temperatures above 28℃. But more than 4 days: the fry that have just completed this process will become thin and their survival rate will decrease. Therefore, when the water temperature of the fish shade pond is lower than 21°C, temperature-raising measures should be taken in time.
2. First-level cultivation stage: When the size of the fry is less than 1 cm, it is the first-level cultivation stage. The nursery pond should choose an indoor hatching pond with a specification of 2-3 m2, a water depth of 12-20 cm, and a stocking density of 4000-5000 tail/m. When the yolk sac of the fry has just been absorbed, a sufficient amount of rotifers filtered through 80 sieve silk should be added as the opening bait, and the transparency of the pool water should be controlled at about 24 cm. After the fry have consumed a large amount of rotifer blood, the density of rotifers in the water body decreases and the water body gradually becomes transparent. At this time, fertilizer water containing a large number of rotifers should be replaced in time. After two days of cultivation, water fleas can be used as bait. It should be noted that feeding water fleas must be filtered through a 40-mesh sieve. When the size of the fry reaches more than 1 cm, it enters the secondary cultivation stage.
3. Secondary cultivation stage: The outdoor nursery pond can be selected for the nursery pond, with an area of ??5-6 meters2, a water depth of 25-30 square meters, and a stocking density of about 2000 ni/m2. Healthy fry at this stage always live in the dark during the day, with very few fry swimming around. They only disperse and look for food in the evening. Therefore, the pool surface should be covered with materials with good heat-shielding properties such as cement tiles 1/ 3 area, on the one hand, it prevents the water temperature from rising greatly when the sun is strong, and on the other hand, it provides a dark habitat space for the fry, which is conducive to the growth of the fry. After the fry are in the pond, feed them water fleas for two days, and when they grow to more than 1.5 cm, you can feed them silkworms instead. After three days of feeding silk earthworms, the size of the fry reaches more than 2 cm, and they are transferred to the third level of cultivation.
4. Third-level cultivation stage: The size of the third-level cultivation pond is 15-30 m2, the water depth should be about 50 cm, the stocking density is 400-500 tail/m2, and a small amount of water lilies are placed in the pond. , covering about 1/4 of the water surface area to purify water quality, provide shade and provide shelter for fish fry. The feed mainly consists of silk earthworms. When the supply of silk earthworms is not available, cooked snail meat can be ground into minced meat or fish meat can be stirred into surimi. The fry can grow to 5 cm in 12-15 days and reach the size for sale.
Feeding and management
1. Feeding: During the fry cultivation process, the fry double their own weight every day, so the amount of feeding changes every day. Pay attention to the feeding situation of the fry every time you feed, and adjust the feeding amount appropriately based on the observation results. Feeding should be done in small amounts with frequent meals, and attention should be paid to an appropriate period of time between each feeding. The amount of feeding should be enough for the fry to finish eating in about half an hour.
3. Separate ponds: The water temperature is suitable and the fry grow very quickly, so it is very easy to form an over-density?
To determine whether there is a "top mouth", it is based on the fact that at 12 o'clock in the evening or when the sun has not come out in the morning, all the fry have surfaced. At this time, when people approach the nursery pond, if the fish make a "summer" sound and all dive into the water, it means that there will be no "smooth mouth". ?;If the fry is unresponsive, still shaking its head and tail on the water surface, and swimming around as if nothing happened, it means "top mouth". According to this situation, the degree of "Dingkou" can be judged, and the degree of "Dingkou" can also be known when dividing Shantou. Pool division must be carried out in the morning and evening, and the operation must be careful to avoid injury to the fry.
Pond culture methods
Pond culture can be divided into two types: monoculture and polyculture.
①Pond conditions: The pond requires sufficient water source, no harmful substances, convenient drainage and irrigation, a flat and solid bottom, a silt thickness of less than 15 cm, and a solid ridge without holes. The pond ridge is more than 40 centimeters above the water surface, and barriers are set up at the water inlet and outlet to prevent escape. Putting water lotus or duckweed on the surface of the pond can not only provide shade, but also purify the water quality and serve as auxiliary feed. Before placing fish species in the pond, the pond must be dried, cleaned, disinfected, and base fertilizer applied, and new water should be injected. Fish species can only be released when the reproduction of feed organisms in the pond water reaches its peak.
The pond area is generally 600-2000 square meters, and the water depth is 1-1.5 meters.
② Fish fingerling stocking: The fish fingerlings for stocking must have the same specifications. The stocking density depends on the size of the fish fingerlings and the conditions of the pond, feed, and water source. Generally, 5 to 10 fish fingerlings of about 10 cm per square meter are placed. tail. Releasing large-sized fish species can improve survival rates and increase production. The size of fish species in the lower pond should be no less than 5 cm.
③ Feeding: When the fish species first enter the pond, they should be fed some high-quality animal feed to allow them to recover as soon as possible and accelerate their growth. Leatherbeard catfish is an omnivorous fish that feeds mainly on animal feed, such as snails, clams, mussels, snails and other shellfish, as well as fly larvae, silkworm pupae, earthworms, animal carcasses and scraps, etc. Shellfish should be fed after their shells are broken, and those with strong toughness need to be broken or minced into pulp to make food balls to improve utilization. Powder feed (fish meal, bone meal, shrimp shell meal, corn meal, rice bran, wheat bran, etc.) is best mixed with meat and fed. If conditions permit, pellet feed with a crude protein content of more than 30% can be formulated according to the nutritional needs of leatherback catfish, which can not only improve feed utilization but also accelerate the growth of the fish. Feeding should be on the feed table. The feed should be a combination of fine and coarse feed, once in the morning, noon and evening every day, and the feeding should adhere to the "Four Certainties".
Appropriate application of organic fertilizers to cultivate zooplankton can meet the feeding needs of leatherback catfish and reduce the feed coefficient.
④Daily management: Clean the feed table frequently to keep the water fresh and prevent fish from becoming hypoxic due to high density. The water should be filtered to avoid introducing parasites and other harmful insects. It is also necessary to prevent snakes and rats from burrowing and fish escaping when the water rises after rain. Regular patrols of the pond should be done to check whether there are any loopholes and whether the fish blocking facilities have been damaged.
Leathery catfish can be mixed with chain fish, bighead carp, carp, grass, tilapia and other fish, but cannot be mixed with carnivorous fish. The size of the fish species raised in the polyculture should be appropriately larger. It is best to reach commercial specifications that year and be able to be put on the market together with the leatherback catfish. Polyculture methods include:
① Mainly use leatherback catfish, with other fish: generally stocking 3 to 6 fish species of 5-6 cm leatherback catfish per square meter, every 2-3 square meters Raise a domestic fish species.
② Mainly other fish, supplemented by leatherback catfish: In an adult fish pond that can feed domestic fish, raise a leatherback catfish with a body length of 6.8 cm per 2.3 square meters. Small miscellaneous fish and aquatic insects in the water are used as their feed, and there is no need to increase feeding.
③ Mixed breeding of leatherback catfish broodstock in adult fish ponds: Put a small amount of reproducible leatherback catfish in a male to female ratio of 1:1 or 1:1.2, and place fish nests during the breeding season to allow them to lay eggs and hatch. . According to the number of breeding Leatherbeard Catfish, some animal feeding is appropriately fed, so that it can directly grow into commercial fish in the adult fish pond. When stocking, the load capacity of the water body after breeding of leatherback catfish should be considered. Characteristics of catfish
The body is elongated, the head is flat, and the tail is flat on the sides. The mouth is in the lower position, the mouth cleft is small, and the end only reaches below the front edge of the eye (the one with the end reaching the back edge of the eye is a large-mouthed catfish). Protruding jaw. The interdentals are thin and villi-shaped. The jaw teeth and pear teeth are arranged in a curved belt shape. The pear bone tooth belt is continuous and the middle part of the posterior edge is slightly concave. The eyes are small and covered with membrane. Adult fish have 2 pairs of barbels, the upper barbels can reach as deep as the end of the pectoral fin, and the lower barbels are shorter. There are 3 pairs of barbels in the juvenile stage, and one pair of mental barbels begins to disappear when the body length reaches about 60 mm. Catfish are mucusy and have no scales.
The dorsal fin is small, has no spines, and has 4-6 fins. No adipose fin. The anal fin is very long and its rear end is connected to the tail fin. The body color of catfish is usually dark brown or gray-black, with slight dark cloud-like patches. Growth Habits of Catfish
Catfish mainly live in the middle and lower layers of rivers, lakes, reservoirs, and ponds. They mostly move along the coast. They mostly hide under grass, rocks or deep water during the day and forage for food at night. frequently. After autumn, they live in deep water living sludge to overwinter, and their feeding level also weakens. Carnivorous fish mostly prey on small fish, such as meal sticks, crucian carp, goby, wheatear, carp, loach, etc. They also eat shrimps and aquatic insects. Mainly for swallowing, the main function of teeth is to prevent food from escaping.
It is a nocturnal animal and hides quietly in pits at the bottom of rivers or under tree roots during the day. Large species with large appetites, such as the Danube catfish, will attack small water birds or mice, as well as ferocious bottom fish. It is afraid of light and likes to live in rock crevices, deep pits, earth holes or stone caves at the base of tree roots near river banks, and in slow-flowing waters.
In the still water of reservoirs, ponds, lakes, and water weirs, they often lie on the dark bottom or under patches of water lilies, water peanuts, and water hyacinths.
Begins to be active in spring, looking for food. They do not eat after winter and spend the winter lurking in deep water or caves. If nothing disturbs them, they generally do not swim.
Catfish has small eyes and weak vision. It is nocturnal and relies entirely on its sense of smell and two pairs of tentacles to hunt. It is very gluttonous. The hotter the weather, the greater its food intake. It is active on cloudy days and at night.
Sexual maturity occurs early, usually within one year of age. The spawning period in the Yangtze River area is from April to June, the earlier it goes to the south, and the later it goes to the north. When laying eggs, they chase each other in groups. Similar to Darwin's frogs, male catfish also hold the eggs laid by female catfish in their mouths to hatch small catfish. The difference is that male catfish cannot eat during this period. Juvenile fish feed on zooplankton and molluscs, among which aquatic insect larvae and shrimp are its delicacies.