Key Management Techniques for Rearing Snakehead Fry in Earthen Ponds

Snakehead is one of the most common fish in our daily lives, and its nutritional value is very high. We all know that fish is rich in protein, and eating fish regularly is very helpful for human health, so we can eat more fish in our daily lives.

Management techniques for rearing snakehead fry in earthen ponds

1. Seine netting and sorting: After about 3 weeks of rearing, the fry reach 2.5-3 cm in length, and the differences between individuals increase relatively, so the phenomenon of the strong eating the weak becomes quite serious, especially when the feed amount is insufficient. By seine netting and sorting through screens, properly reducing the rearing density and striving for uniform size, the strong eating the weak can be avoided. Seine netting and sorting should be carried out on clear days. The fry must not be full-fed when netting, so feeding must be stopped for 1 day before netting. If the fish in the pond are gasping at the surface, netting must not be carried out either, otherwise it will cause mass death. Netting is generally scheduled after 8-9 a.m., and the netting operation must be careful and meticulous to prevent injury to the fry. The net is best made of soft materials (vinylon thread, nylon thread), and when moving the fry, they must be handled with water. After another 3 weeks or so of rearing, the fry grow to more than 6 cm and become small-sized fingerlings, which can be taken out of the pond for continued rearing into large-sized fingerlings. This is at the end of June and the beginning of July, when the air and water temperatures are relatively high, so clear days must likewise be chosen, and harvesting is done from 7-10 a.m. After 10 a.m. the water temperature keeps rising, so harvesting is not suitable. During harvesting, the operation must be careful, the movements must be quick, and damage to the fingerlings must be reduced; likewise, they must be stocked separately according to size.

2. Water quality management: With fertilization of the rearing pond, feeding and the growth of the fry, the water quality very easily becomes too fertile or even deteriorates, affecting the survival rate of the fry, so new water needs to be added at the proper time to regulate water quality. Generally, water is added once about every 1 week. When the fry are stocked, the water level is only 40-50 cm. In the early stage, the water level is raised by adding water, diluting the water quality, with 5-10 cm added each time, and later 10-15 cm can be added each time, until the required water depth is reached. Maintaining a certain water volume can increase the activity space for the fry, reduce the concentration of harmful substances in the water, improve the chemical conditions in the water body, and promote the growth of the fry. When adding water, attention must be paid to promptly regulating the fertility level of the pond water, especially to prevent the pond water from becoming too fertile. Afterward, a water exchange method of letting water in while draining water out is adopted for regulation, strictly controlling water quality, so that the fry can grow healthily in a good ecological environment and the survival rate of the fry can be increased. 3. Pond patrols: A dedicated person must patrol the pond at fixed times every day. This work is a very important task in daily management, as it can promptly discover and solve problems. Generally, pond patrols are conducted 3 times a day, in the morning, at noon and in the evening, and the morning and evening patrols are especially important. In the morning, pay attention to whether the fry are gasping at the surface. If they are, pay attention to whether the water is too fertile, and according to the situation of gasping at the surface, take corresponding measures such as adding new water to control it, preventing fish kill accidents. During the evening pond patrol, if the fry are found to be clustering rather seriously, they should be dispersed promptly or their position should be shifted, especially when they cluster at the downwind outlet, efforts should be made to move them to the upwind inlet or elsewhere. During daytime observation on patrol, if the fry are found swimming back and forth along the pond edge, this is a sign of the fry searching for food due to hunger, indicating that the feed amount is insufficient, and the feed amount should be increased. During the day, attention must also be paid to changes in water quality, especially when the weather is hot, the water is relatively fertile and algae are abundant and excessive, there will appear the phenomenon that the water is relatively clear in the morning, relatively green at noon, and a large amount of water bloom (algal scum) floats on the water surface in the evening. Water should be changed appropriately to reduce the fertility level and remove the algal scum. 4. Survival rate of fry rearing: According to statistics from reports over the years on snakehead fry breeding, during the fry rearing stage, that is, rearing to fry with a total length of 3-4 cm, the survival rate generally reaches 60%-65%.

How to raise snakehead well  

1. Pond construction: Choose an east-west oriented, rectangular pond, with a mud bottom, a pond depth of 2-2.5 m and a water depth of 1.5-2 m. Anti-escape facilities must be installed at the inlet and outlet. Apply quicklime at 100-150 kg/mu 15 days before rearing for thorough disinfection.  

2. Fingerling stocking: Before the fingerlings are put into the pond, soak them in 3%-5% salt water for 10-15 minutes, then put them into the pond. For fingerlings with a body length of 10-14 cm, the stocking density is 9000-10000 fish/mu; for fingerlings of 16-20 cm, the stocking density is 8000 fish/mu.  

3. Daily management: Pay attention to observing snakehead feeding, activity, disease trends and environmental changes. In spring, change 4/5 of the pond water every week; in the high-temperature season, make a small water change every 3 days and a large water change every 7 days. Install anti-escape nets at the inlet and outlet, and it is best for the pond bank to be more than 50 cm above the water surface. The discharged wastewater should undergo necessary wastewater treatment.  

4. Feed feeding: The feed for raising snakehead includes artificial compound feed, freshwater or saltwater small trash fish, and scraps left after livestock and poultry slaughter. Before feeding small trash fish, they need to be sorted to remove fish with hard spines, such as yellow catfish, etc. Before feeding, use tapping as a signal to gather the fish from afar near the feeding table, reducing feed waste. The initial feeding amount is 10% of body weight, and later it can be appropriately reduced to about 5% of body weight. Feeding should be done one spoonful at a time, so that less feed is wasted.

Snakehead rearing cycle  

The fry of the current year for snakehead are generally stocked from May to July, and the specific time depends on differences in regional air temperature, water temperature, climate and other conditions.  

It is hard to determine how long it takes for snakehead to grow to 1500 g. This is related to factors such as your rearing technology level and the quality of the bait selected, and it depends specifically on the actual rearing environment. It is recommended that during rearing you choose ponds with good conditions, high-quality fry and good-quality bait for feeding, and do a good job in daily management and disease prevention and control in normal times, so as to shorten the snakehead rearing cycle as much as possible.  

If the rearing method is correct, the snakehead rearing cycle is one year of rearing to reach one and a half to two jin.

Nutritional value of snakehead  

Snakehead has high nutritional value. It has very good dietary therapeutic effects on physical weakness, hypoproteinemia, malnutrition, spleen-stomach qi deficiency and anemia, and eating snakehead has a very good anti-inflammatory effect on wounds. Snakehead itself has relatively coarse flesh, and compared with other fish its taste is not as good, so it does not taste very good to eat, but if snakehead is used to make soup, the taste is simply unbeatable!   Snakehead has very strong vitality, and its flesh tastes sweet. It contains a large amount of various minerals such as iron, calcium and phosphorus, and its nutritional components are also very rich, containing fat, protein, vitamin A, B vitamins, etc. In addition, in every 100 g of snakehead, the protein content can reach as high as 20 g, second only to shrimp, and snakehead is easily digested and absorbed by the human body. Regular consumption of snakehead can enhance resistance.  

Secondly, snakehead also has medicinal value in promoting blood circulation and dredging collaterals, strengthening the spleen and draining dampness, harmonizing the middle and opening the appetite, and warming the middle and descending qi. It has very good tonic and dietary therapeutic effects on weakness of the kidney and spleen, ulcers, edema, asthma, bronchitis and diabetic patients; for postpartum pregnant women, it can also tonify deficiency and promote lactation. In the chilly winter, the taste of snakehead is especially delicious. Regular consumption of snakehead can not only strengthen the body but also help with weight loss, help lower blood pressure and blood lipids, and make people live longer. Traditional Chinese medicine believes that snakehead can both tonify deficiency and warm the middle and descend qi, and promote diuresis and reduce swelling. Plain-cooked snakehead has a very good effect on treating gastrointestinal bleeding and vomiting and retching.

With the continuous development of our country's aquaculture industry, snakehead farming is currently a fairly well-developed aquaculture project in the aquaculture industry, but farmers must also master certain farming techniques during the rearing process, so as to avoid taking detours.