Management techniques for cultivation of black fish fry in soil pond

Black fish is the most common kind of fish in our life, the nutritional value of black fish is very high, we all know that the protein content of fish is very high, often eating fish is very helpful to human health, so we can eat more fish in life.

Management techniques for cultivation of black fish fry in soil pond

1. Net separate culture: after about 3 weeks of cultivation, the length of fish fry is 2.5 cm, and the difference between individuals is relatively increased, so the phenomenon of weakness is more serious, especially in the case of insufficient feeding. By pulling the net, sieving and breeding, properly reducing the breeding density and striving for consistency in size, we can avoid eating the strong and eating the weak. Fishing should choose sunny weather, fish fry can not be full when pulling the net, so stop eating for 1 day before pulling the net. If the fish are floating in the pond, do not pull the net, otherwise it will cause a large number of deaths. The net-pulling time is generally arranged after 8: 9 am, and the net-pulling operation should be careful to prevent seedling injury. The net is best made of soft materials (vinylon thread, nylon thread), and must be operated with water when moving fish fry. After about 3 weeks of cultivation, the fry grows to more than 6 cm and becomes a small size fish, which can go out of the pond and continue to cultivate large size fish species. At this time, it is the end of June and early July, and the air temperature and water temperature are relatively high, so we should also choose a sunny day and fish at 7: 10 am. The water temperature keeps rising after 10:00, so it is not suitable for fishing. When fishing, you should be careful, move quickly, reduce the damage to the fish species, and also breed separately according to the size.

2. Water quality management: with the fertilization and feeding of the cultivation pond and the growth of fish fry, the water quality is easy to be overfertilized or even deteriorated, affecting the survival rate of fish fry, so it is necessary to inject new water in time to regulate the water quality. Generally, the water is injected once in about a week. The water level was only 40-50 cm when the seedlings were put in. In the early stage, the water level was raised by adding water to dilute the water quality, adding 5-10 cm at a time, and then adding 10-15 cm at a time until the water was as deep as it should be. Keeping a certain volume of water can increase the activity space of fish fry, reduce the concentration of harmful substances in the water, improve the chemical status in the water, and promote the growth of fish fry. When adding water, we should pay attention to adjust the fat and thinness of the pool water in time, especially to prevent the pool water from being too fat. After that, we should adopt the way of changing water while entering and draining, strictly control the water quality, make the fish fry grow healthily in a good ecological environment, and improve the survival rate of fish fry. 3. Patrol the pond: there should be a special person to patrol the pond regularly every day. This work is a very important work in daily management, which can find and solve problems in time. Generally, the pond patrol is made three times a day in the morning, in the middle and in the evening, especially in the morning and evening. In the morning, we should pay attention to whether the fry is floating, if there is a floating head, we should pay attention to whether the water quality is too fat, and take corresponding measures such as injecting new water according to the floating head to prevent the occurrence of dead fish accidents. If the fry cluster is found to be serious when patrolling the pond at night, it should be dispersed or moved in time, especially in the downwind cluster, we should try to move it to the upwind or other places. If fish fry are found to swim back and forth along the edge of the pond when observing the pond during the day, this is the phenomenon of fish fry starving for food, indicating that the feeding quantity is insufficient and should be increased. During the day, we should also pay attention to the changes of water quality, especially when the weather is hot, the water quality is more fertile, and the algae is abundant, the water quality is clearer in the morning, the water quality is greener at noon, and there is a large amount of bloom (algal skin) floating on the water surface in the evening, so we should change the water properly, reduce the fertility and remove the algal skin. 4. The survival rate of fish fry cultivation: according to the statistics reported over the years on the propagation of black mackerel fry, in the fry cultivation stage, that is, the fry with a total length of 3 cm to 4 cm, the survival rate is generally up to 60% and 65%.

How to raise black fish

1. Pond construction: choose the east-west direction, rectangular pond, the bottom of the pond is soil, the depth of the pond is 2-2.5 meters, the water depth is 1.5-2 meters, the inlet and drainage should be equipped with anti-escape facilities, and 100kg / mu of quicklime should be thoroughly disinfected 15 days before breeding.

2. Fish stocking: before entering the pond, the fish should be soaked in 3% to 5% salt water for 10 minutes for 15 minutes, and then put into the pond. The fish species with a body length of 10 centimeters and 14 centimeters will have a stocking density of 9000 million fish per mu and 16 fish species per mu, and the stocking density is 8000 fish per mu.

3. Daily management: pay attention to observe the feeding, activities, morbidity trend and environmental changes of black fish. Change the pool water 4 times a week in spring, a small change every 3 days in the high temperature season, a big change every 7 days, enter and drain to catch the escape net, and the pool ridge is more than 50 cm above the surface of the water. For the discharged sewage, the necessary sewage treatment should be carried out.

4. Feed feeding: feed for black fish, including artificial compound feed, small miscellaneous fish of fresh water or sea water, and scraps of livestock and poultry after slaughter. Before feeding, small miscellaneous fish need to be sorted to remove fish with hard spines, such as Pelteobagrus fulvidraco. Before feeding, use slapping as a signal to concentrate distant fish near the bait table to reduce feed waste. The initial feeding amount is 10% of body weight, and then it can be appropriately reduced to about 5% of body weight. It should be fed with one spoonful, so that the waste of feed is less.

Black fish culture cycle

The fry of black fish are generally released from May to July, depending on the differences in regional air temperature, water temperature, climate and other conditions.

It is difficult to determine how long it takes for black fish to grow to 1500 grams, which is related to your culture technology level, bait quality and other factors, depending on the actual culture environment and so on. It is recommended that you choose good ponds, high-quality seedlings and good-quality bait in the process of culture, and do a good job in daily management and disease prevention in peacetime, so as to shorten the culture cycle of black fish as much as possible.

If the culture method is correct, the culture cycle of black fish can be one and a half to two jin a year.

Nutritional value of black fish

Black fish has high nutritional value, it is weak, hypoproteinemia, malnutrition, spleen and stomach qi deficiency, anemia has a very good food effect, eating black fish has a very good anti-inflammatory effect on the wound. Black fish itself is relatively thick meat, compared with other fish taste is not so good, it is not very delicious, but using black fish to make soup, the taste is invincible! The vitality of black fish is very strong, and the meat is sweet, it contains a lot of iron, calcium, phosphorus and other minerals, nutrients are also very rich, including fat, protein, vitamin A, B vitamins and so on. In addition, every 100 grams of black fish, the protein content can be as high as 20 grams, second only to shrimp, and eating black fish is easy to be digested and absorbed by the human body, often eating black fish can enhance resistance.

Secondly, black fish also has the medicinal value of promoting blood circulation and dredging collaterals, invigorating spleen and promoting dampness, appetizer, warm lower qi, and has a good nourishing and therapeutic effect on patients with kidney and spleen weakness, ulcer, edema, asthma, tracheitis and diabetes; for postpartum pregnant women, it can also replenish deficiency and lower milk. In the cold and windy winter, the taste of black fish is especially delicious. Eating blackfish often can not only keep fit, but also lose weight, help to lower blood pressure and blood lipids, and prolong life. Traditional Chinese medicine believes that black fish can not only replenish deficiency, but also warm lower qi, promote diuresis and reduce swelling. Braised black fish is very effective in the treatment of gastrointestinal bleeding and vomiting.

With the continuous development of China's aquaculture industry, blackfish culture is a good aquaculture project in the current aquaculture industry, but farmers should also master certain culture techniques in the process of culture, so as to avoid detours.