Technical video of black fish culture

Black fish is a valuable freshwater fish with high economic value, which is called "the treasure of fish". It is very nutritious and contains a lot of protein, which is higher than that of chicken and beef. From the point of view of nutrition, black fish is a kind of advanced health food with comprehensive nutrition and delicious meat. Black fish sells well at home and abroad, and the price is expensive. It is one of the important aquatic products exported by our foreign trade, and it is also a kind of tight and high-priced food in the domestic market.

The living habits of Blackfish

1. Living habits: black fish are benthic fish, which live in a wide range of habitats. Therefore, where frogs, Loach, crucian carp and all kinds of aquatic insects live in groups are all places where black fish like to live. Black fish often lurk in shallow water with a depth of 1 meter. The living temperature of black fish is 0 ℃ 41 ℃, and the optimum temperature is 16 ℃ 30 mol. When the water temperature rises above 8 ℃ in spring, the black fish begins to move and swim from deep water to shallow water to look for food. It grows faster when the water temperature is above 20 ℃. When it is sultry and rainy in summer, it tends to jump out of the water and crawl on the wetlands on the shore. In autumn, when the water temperature drops to 12 ℃, stop feeding; drop to 6 ℃ and move to deep water. When the water temperature is too low in winter, it is buried in the mud to survive the winter, as long as there is water under the ice. Black fish can tolerate hypoxia. It can also survive in turbid and anoxic water. When there is a lack of oxygen in the water, the fish can put its head out of the water and use the organs on the gills to directly absorb the oxygen in the air for gas exchange. PH value: black fish can generally live in acidic and alkaline waters. Black fish is good at jumping: its jumping ability is very strong, and its jumping is also high. It is easier to stimulate the black fish to jump and escape when there is water impact and rain, and often go up with the current.

2. Feeding habits: black fish is a fierce carnivorous fish. Mainly feed on small fish, shrimp, frogs and tadpoles, aquatic insects and other aquatic animals. The specific kinds of food consumed vary with the size, season and water environment of the fish. But in any case, it will not change the nature of its carnivorous nutritional type.

3. Growth: the fish hatched in that year are generally about 150 mm long and weigh about 50 grams. The body length of 2-year-old fish accelerated the growth stage and grew vigorously. After 2 years old, it showed a decreasing trend with the increase of age. When the water temperature is 20 ℃ and 25 min, the growth rate is faster.

4. Reproduction

The age of sexual maturity of ①: the Yangtze River valley is generally 2 winter years old, and the local area generally begins to mature and lay eggs in the third year.

The number of eggs conceived in ②: the average number of eggs carried by an individual is 10-30 000, and the largest is 50-60 000. The number of eggs is different in individuals of different ages and sizes and in different water bodies.

Artificial reproduction of black fish

1. Parent fish selection: the quality of parent fish is the key factor of artificial reproduction. It is more suitable for individuals whose age is over 2 years old and weight is 500g-1500 g. Parent fish that have reached sexual maturity, disease-free, disease-free, large and good growth performance should be selected.

2. Identification of male and female parent fish: there is no obvious difference in secondary sexual characteristics between male and female black fish, so it is sometimes difficult to identify them in appearance. In the reproductive season: the abdomen of female fish is dilated and soft, the reproductive pore is reddish slightly prominent, and the abdomen is grayish white; the abdomen of male fish is smaller, not as soft as female fish, and the reproductive foramen is slightly concave.

3. Artificial spawning: parent fish are paired at 1:1 and put directly into the spawning pond to wait for natural spawning. artificial spawning can also be carried out. The spawning pond area of 0.1 Mu is suitable, and the best bottom is 1 meter deep and 0.3 meters shallow. Grass is planted or thrown in the pond, and it is better to have more transparent and thin water. It can also spawn in parent fish culture ponds. Artificial induced labor should choose the gonad to the end of Ⅳ stage development, the water temperature is 25 ℃ 28 min, the general time is from late May to mid-June. The effects of chorionic gonadotropin and carp pituitary were better in artificial induced labor drugs. Pituitary 4Mel 6 / kg, chorionic gonadal hormone 1600MUR 2400 international unit, ♂ halved. Those with poor maturity can be injected twice with an interval of 24 hours. The injection site is body cavity injection. The parent fish can be spawned and fertilized automatically after 25 hours of 18 ℃ at 23 Mel 30.

4. Artificial hatching: after spawning and fertilizing in the spawning pond, the parent fish can be fished out with a small fishing net on a fish plate and concentrated in the incubator or other containers to hatch. General noodle basin puts 500, plastic big basin 5000Mill 8000, small net cage 10-20,000 / square meter. Generally 2Mel 3 days later can hatch fish fry, shaped like tadpoles, gray-white body, with their own yolk as nutrition. 4After 5 days of yolk absorption, live water fleas should be fed immediately. The amount of water flea is based on the food intake of fish fry, and it is appropriate to use a small amount of water flea for many times. The fish turned yellow after feeding 5 Mel for 6 days, with a total length of about 1.5 cm. That is, it can be moved to a small pond to cultivate and hatch.

① picked out the dead eggs at any time to control the infection of water mold. The white eggs were found after 10 hours, that is, the unfertilized eggs were picked out.

The ② incubator was disinfected with 0.1ppm malachite green pond water before releasing eggs. Wait for 24 hours to use.

③ keep the water clean and pay attention to the change of water. Once a day to prevent hypoxia.

④ should not change water too much after hatching to prevent temperature change too much. On the day when the eggs are laid, the amount of water exchanged accounts for 60% of the total water volume, and 80% from the second to the fifth day. The temperature change of the water should not exceed 2 ℃. The hatching water temperature should be controlled at 24 ℃ 30 min, 25 mi 28 in still water for about 33 mi 38 hours, and 23 mi 25 ℃ for 36 hours.

Seedling cultivation

It is generally believed that "it is easier for black fish to hatch than to cultivate seedlings". The survival rate of fish fry is 70% 80%, and the low 20% is even wiped out. There are two kinds of cultivation methods: one is to cultivate fish fry at one time, and the other is to cultivate fish fry and fry in two stages.

Larval domestication

The newly hatched fish fry 3.8ml 4.3mm floats on the surface with its own yolk sac as nutrition. The body is much more delicate than domestic fry, and it is more difficult to manage. Therefore, you should first domesticate in plastic pots, small cement ponds, plastic film "soil ponds" or the original incubator for a few days, and then move into the fry culture pond when you can swim in groups and run and feed on zooplankton. When domesticated, the general depth of the cement pond is about 60 cm, with 13000 larvae per square meter. 3After 5 days, the yolk sac disappeared and began to ingest bait, which should be fed immediately. At first, add the yolk liquid (mix the yolk weight with twice the water) 3 milliliters, three times a day. It can also be fed to rotifer, Cladocera, copepod larvae (filtered with a sieve of 32mer 40 mesh per square centimeter) and fed with small ones. After 5 days of domestication (that is, 9-10 days after hatching), the seedlings are yellow, and when they can swim freely (can sink and swim to the surface of the water) and feed in groups, the fry should be gradually moved into larger ponds or cages for fry rearing.

Fish fry rearing (body length 3ml / 4cm)

1. Cement pool: ① is long, square and round, and the general rectangular type is better. The suitable water depth is 0.6 meters at 4MUE 8 square meters. ② was sterilized and injected with water. The stocking density of ③ is 400,800 per square meter. ④ bait: still feed on zooplankton, rotifers and water fleas should be fed. When natural bait is insufficient, artificial bait should be added. After 2 weeks, the seedlings grow up slightly and the food intake doubles. At this time, large crustaceans and chopped silk earthworms can be fed once a day in the morning and evening, and chopped low-quality mixed fish can be fed 20 days later. ⑤ feeding and management: adjust the water quality, when the normal dissolved oxygen content is more than 3.2ml / m3 and lower than 2.4ml / m3, the fry will die. Separate in time. After 3 weeks of feeding, it will generally reach 3mi 4cm, which will be screened and raised in time. But no later than 5m / m / 6cm. 5Mel 6cm began to prey on small fish and shrimp, eating big and small when lack of bait.

2. Pond cultivation: ① pond disinfection and application of base fertilizer. An area of 100 square meters of 300 square meters, generally about 100 square meters is appropriate. The stocking density of ② is 60-80 000 / mu and the water depth is 0.6 million meters. ③ fertilizers and baits. Daily management of ④. Patrol the pond, timely water injection, pull net and separate cultivation.

3. Cage cultivation: ① material: Nisheng, plastic sieve silk, with an area of 10 square meters, a height of 0.5 mi 0.8 m and a water depth of 0.3 mi 0.6 m. ② cage erection: made of wood or bamboo frame, eight corners fixed on the frame, the whole cage can rise and fall with the water, set up in the fish pond with fertile water quality, rich bait, convenient management and shelter from the wind. ③ density: about 4000 per square meter. ④ bait and daily management are the same. 5Mel was raised for 6 days and then raised in boxes.

4. The cause of death of fish fry in the seedling stage: ① lacks enough delicious bait. At the initial stage of fish fry cultivation, due to the high stocking density, fish fry lack of palatable bait organisms, such as Cladocera, copepod, rotifer, water flea and so on, which often cause a large number of deaths. In the middle and later period, due to the lack of animal feed, resulting in different growth of fish fry caused to kill each other, less and less every day. ② is short of oxygen. The fry died because of its small water body, high density, insufficient dissolved oxygen and low pressure on cloudy days, resulting in floating head for a long time. The weather changes abruptly in ③. When the water temperature is more than 30 ℃ in midsummer, the temperature difference of pool water changes greatly during rainstorm, which is most likely to cause a large number of deaths.

Fish breeding

After the fry grows to 3mil 4cm, the diet begins to change, requiring more food and more room for movement. If the fry is still kept in the original pond, the density is too high, which will affect the growth of the fish. Therefore, it is generally necessary to go through the fish breeding stage, continue to raise the fillets after sifting in the ponds until the winter of the same year, develop species of about ten centimeters or more, and then put them into all kinds of mixed ponds or monoculture of edible fish. But there are also places where black larvae are bred directly into fish species of about 10 centimeters in small ponds.

1. Preparation before stocking: the basic conditions of fish fry ponds are generally the same as those of fish fry ponds, which are generally cultivated in large soil ponds, with an area of 0.5 acres and a water depth of 0.5 Mu. Before entering the pond, the pond should carry out a series of work, such as cleaning and disinfection, fertilization and water cultivation.

2. Fish stocking: when a large number of zooplankton are propagated in the pond, the fillet fish of the same size (3mur4 cm) will be released into the pond at the rate of 20,000 to 50,000 per mu.

3. Feeding: after the summer flowers enter the pond, they still need to top fertilize, cultivate water quality, breed zooplankton and feed the fish. With the gradual growth of the fish and the change of feeding habits, the zooplankton in the pond can no longer meet their feeding needs. Therefore, adequate feed must be given, and the amount of animal feed should be gradually increased. Minced fish, shrimp or fresh water fleas should be fed every day, usually 3 kilograms per 10,000 tails per day. It can also gradually smash the offal and bones of miscellaneous fish in animal feed, mix with wheat flour and feed. It is best to feed chopped fish and shrimp. Generally speaking, fish species can grow to more than 10 centimeters after September. Adult fish culture can be carried out the following year.

Adult culture of black fish

Black fish adult fish culture refers to the production process of cultivating all kinds of fish species into edible fish in ponds, bay ponds, ponds, cages and other small water bodies. There are two kinds of artificially cultured black fish: extensive mixed culture and intensive monoculture. Extensive mixed culture refers to mixed culture with Sijie fish in fish ponds, while intensive monoculture refers to high-density monoculture with abundant water sources, sufficient bait and conditions. It is divided into cage culture and pond culture. In recent years, our city mainly adopts high-density monoculture in ponds. Now briefly described as follows, for reference only.

High density monoculture in pond

1. Preparation before breeding

① aquaculture facilities: soil ponds, cement ponds, etc. The depth of water is 1m / m / m. The water lifting equipment is complete.

② water source: River water, reservoir water, underground well water, etc., the water quality should be neutral or weakly alkaline.

③ area: in order to facilitate production management and sales, the area of fish ponds should be smaller, preferably about 1 mu, and the maximum should not exceed 2 mu.

④ had better have an inlet and drain. Anti-escape facilities such as a net block of 40ml and 60cm shall be set up around the pool.

⑤ plant water grass on the water around the pool, generally not more than 20%, as a shelter, easy to block the sun, summer, prey, but also can purify water quality and adjust water temperature.

⑥ must clean and disinfect the pond before releasing the fish seed.

2. Culture technology

(1) Fish stocking: ① fingerling specifications: choose more than 10cm (preferably 14Mel 20cm, 60g-100g) in the same year, the specifications should be the same, no injury and no disease. Source of ② fish species: it is best to choose locally produced fish species. ③ stocking time: the best time is from September to early October, which can be ingested to restore physique and improve the survival rate of overwintering. It will be released from March to April after 20 years. ④ disinfection: it must be strictly sterilized before entering the pond, generally soaking in 5% salt water for 15 minutes or 10ppm malachite green solution for 10 minutes. ⑤ stocking density: the stocking density is 1.2m deep, about 50ml / mu, about 60g / mu, 8000mu / mu and 5000mu / mu, respectively. If the average water depth decreases, the stocking amount will decrease accordingly.

(2) feeding and management: the baiting should adhere to the "four determinations". Before feeding, the clapping sound is used as a "signal" to form a "sensory" response, and the black fish are gathered around the food field, which is easy to form a feeding situation, increase food intake and reduce bait waste. The main kinds of bait are fresh animals, mainly sea and fresh water fish and shrimp. In fresh water, there are meal sticks, wheat ears, sand climbing, juvenile fish white, small crucian carp, small horse non-fish, fish skin next to fish, green little, small green shrimp, etc., and sardines, green (yellow) fish and other small miscellaneous fish in the sea water. When eating prosperous food, the amount of bait is about 8% of the weight of the fish, and the high one can reach more than 10%. In the off-season, it is 3MUE 4%. The feeding method of "slow, fast and slow" has a good feeding effect and less feed waste, and most of the fish can stop feeding after running away. The food intake of fish is very different because of the good weather, high and low air pressure and good water quality.

(3) daily management: mainly do a good job in the following aspects. ① pond patrol: observe fish feeding, activities, changes in water quality, whether there are signs of floating head, whether there are sick fish, etc., find problems should be dealt with in time. ② change water: black fish ingest high protein food every day, the concentration of ammonia in the pond water is high, especially in summer, the water body is easy to deteriorate. To this end, it is necessary to change the water body in time, generally changing to 1 ℃ per week and 4 to 5 in half a month. Specifically, the change of water quality should be flexibly mastered. Where there are conditions, it is best to keep micro-flow aquaculture. During the culture period, the water temperature should be no higher than 30 ppm. ③ anti-escape: at the initial stage of black fish stocking, the fish species are still small and the jumping ability is poor. When growing gradually, the jumping ability is enhanced greatly, especially when the water is changed in rainy days or in the early morning, so the height of the pool ridge from the water surface should generally be more than 50 centimeters, and a strong anti-escape net should be installed at the inlet and outlet. Anti-escape net or anti-escape wall is installed around the pool.

3. Changfeng fish disease and its prevention and cure.

① water mildew: prevention and control methods: in the operation of net transportation and stocking, it is necessary to be as careful as possible to prevent fish from injury; disinfect the whole pond with malachite green of 0.1ppm or methyl blue of 0.5ppm. When fish get sick, they can be washed with malachite green of 10ppm or saline solution of 35% concentration.

② enteritis: prevention and treatment: 34 grams of furazolidone (furazolidone) was mixed in 100kg diet and fed twice a day for 3 consecutive days.

③ myxosporidiosis: control method, with 0.2-0.5ppm concentration of 90% crystal trichlorfon treatment.