Key Technical Points for Artificial Breeding and Hatching Management of Snakehead

The snakehead is a fairly commonly eaten fish in China. It is a fairly common delicacy on the dining table, and its nutritional value is extremely rich. The protein content of snakehead is very high, and eating more snakehead has a certain effect on reducing inflammation in human wounds. Therefore, in daily life, many women buy snakehead to eat after undergoing cesarean section.

Hatching management of artificial snakehead breeding

The fertilization rate, the quality of water conditions, and whether dead eggs, dead embryos and dead fry can be removed in time will directly affect the hatching rate. Therefore, in the process of production hatching, the following points must be done well:

1. Handle gently: prevent damage to fish eggs. When handling and moving fish eggs, use basins, ladles, bowls and other containers with water to move them. 2. Keep the water fresh: it is best to maintain the water body at a tender green color, so that the water contains an appropriate amount of phytoplankton. In still-water hatching, 1/3 to 1/2 of the water body should be replaced every day. It is best to adopt the method of draining while refilling, maintaining the original water level. The inlet and drainage speed should be slower to prevent the inflow from being too rapid and impacting and vibrating the fertilized eggs, which would affect embryonic development. In micro-flow hatching, the inflow speed should likewise be slow. Insist on removing filth every day. Surface filth is generally removed with a dip net, and bottom filth is sucked out with a siphon tube. After the fry emerge from the membrane, the egg membranes must be removed in time to prevent the egg membranes from depositing and decaying and causing deterioration of water quality. For eggs hatched in hatching ponds or left in the original spawning pond to hatch, the water should generally be changed once a day, discharging part of the old water and adding part of new water, while maintaining the original water level. It is worth noting that after hatching begins, it is not appropriate to change too much water, so as to avoid excessive changes in water temperature that make the fry unaccustomed and prone to disease. Generally, on the day the larvae hatch, the water exchange volume of the hatching pond accounts for 60% to 70% of the total water volume; from the 2nd day to the 5th day, the water exchange volume can account for 80%. 3. Control the occurrence of saprolegniasis: during the fish egg hatching period, controlling saprolegnia infection is extremely important. At the most suitable hatching water temperature, it is also the period of high incidence of saprolegniasis. Generally, unfertilized bad eggs turn white in about 10-plus hours, and dead eggs or moldy eggs must be removed manually in time. When saprolegniasis occurs during hatching, if the number of infected eggs is small, the diseased eggs can be removed with a net; if white bad eggs account for the majority, the number of infections is large, and the harm is great, they can already swim downward.

4. Prevent sudden changes in water temperature: when changing water, the temperature difference between the new water added and the water in the pond should not be too large. Generally, after changing water, the temperature difference in the hatching pond should be controlled not to exceed 2 degrees C. For this reason, for newly hatched fry ponds, the water exchange volume should not be too large; the hatching facility is best covered with a shading shed to prevent direct sunlight and rainwater inflow, which would cause drastic changes in pond water temperature and rain droplets striking the fertilized eggs. 5. Prevent oxygen deficiency: the main reason for oxygen deficiency in the hatching water body is that there is too much organic matter in the hatching water. When these organic substances decay, the organic oxygen consumption is large, leading to oxygen deficiency. The organic matter in the hatching water comes from the water source itself and from dead eggs, dead embryos and dead fry that are not removed in time during the hatching process and produce decay. Sometimes oxygen-deficient groundwater is injected into the hatching pond without aeration. In addition, because there are oil globules in snakehead eggs, when these eggs rupture for various reasons, these oil globules are released into the water and form a thin oil seal on the surface of the hatching water. In addition, during the hatching process of fertilized eggs, embryonic development consumes a particularly large amount of oxygen, which leads to oxygen deficiency in the water body.

Oxygen deficiency in the hatching water body not only affects hatching, but also further increases dead embryos. In addition, if these dead eggs and dead embryos are not removed in time during management and then decay and rupture, oil droplets are released, further intensifying the oxygen deficiency of the water body caused by the oil seal and increased organic oxygen consumption, forming a vicious cycle. Therefore, in management, it is necessary not only to remove pollutants from the water body, but also to remove dead eggs and dead embryos in time before they rupture, so as to avoid releasing oil droplets. At the same time, when changing water, pay attention to gently replacing the surface water layer containing the oil seal. The operation process should be light and quick to avoid rupture of the eggs.

The economic value of snakehead  

As a valuable freshwater fish with relatively high economic value, the snakehead is known as a “treasure among fish.” Its nutrition is very rich. The meat contains a large amount of protein, higher than the protein content of chicken and beef. According to measurements, 100 grams of snakehead meat contains 19.8 grams of protein, 1.4 grams of fat, 1.2 grams of ash, 57 mg of calcium, 163 mg of phosphorus, 0.5 mg of iron, and 77.9 grams of water; it contains 383.5 kilojoules of calories. Its protein contains rich amino acids. The content of umami amino acids accounts for 47.36% of the total amino acids, and the content of essential fatty acids accounts for about 16% of the total fatty acids. Therefore, from a nutritional perspective, snakehead is a high-grade health food with comprehensive nutrition and delicious meat.  

When used for food, snakehead has few bones and an edible rate of 63%. The edible rate of the snakehead murrel can be as high as 75.63%. In cooking, snakehead meat is smooth and refreshing, suitable for stir-fried fish slices, stir-fried fish scales, and hot pot; while the banded snakehead is suitable for stewing and simmering, and the fish soup cooked has no fishy smell, a rich fragrance, and tender fish meat. The “cai yu slices” cooked with snakehead are even more a world-renowned delicious dish.  

In medicinal use, snakehead has the effects of removing blood stasis, promoting tissue regeneration and nourishing. Eating snakehead after surgery or trauma has the effects of promoting tissue regeneration, replenishing blood, astringing, and promoting wound healing. Weak patients, postpartum women and children often eating snakehead is beneficial to health. In southern China, especially in Guangdong, Guangxi and the Hong Kong and Macao regions, snakehead is generally regarded as a nourishing delicacy for patients and the frail elderly and young. Guangdong's famous “snakehead and kudzu soup” has the effects of clearing heat and detoxifying, promoting fluid production and quenching thirst, drawing out toxins and promoting tissue regeneration, and is very much liked by the masses.

The nutritional value of snakehead  

1. Snakehead meat contains protein, fat, 18 kinds of amino acids, etc., and also contains calcium, phosphorus, iron and multiple vitamins necessary for the human body.  

2. It is suitable for people with physical weakness, hypoproteinemia, spleen-stomach qi deficiency, malnutrition, and anemia. In the Guangxi area, folk people often regard snakehead as a precious tonic, using it to promote lactation and replenish blood;  

3. Snakehead has the effects of dispelling wind and treating malnutrition, tonifying the spleen and replenishing qi, and promoting diuresis and reducing swelling. Therefore, in the Three-North region, postpartum women, rheumatism patients, and children with malnutrition often seek out snakehead murrel to eat as an auxiliary dietary therapy.  

4. The vitality index of snakehead is 0, but the disease prevention index is 6.41.

The living habits of snakehead  

The survival water temperature of snakehead is 0-38 degrees C, and the most suitable water temperature is 16-30 degrees C. When the water temperature rises above 8 degrees C in spring, snakehead often moves in the middle and upper layers of the water body; when the water temperature drops below 6 degrees C in autumn, it swims slowly and often lurks in deep water; when the water temperature is too low in winter, it lies dormant at the bottom.  

Snakehead is a carnivorous fish, and its food varies with the size of the fish body. Young fish below 3 cm mainly feed on copepods, cladocerans and chironomid larvae, etc. Small fish with a body length of 3-8 cm mainly feed on larvae of aquatic insects, maggots, small fish, small shrimp and small tadpoles. Adult fish above 20 cm mainly feed on small wild miscellaneous fish, shrimp, frogs and other carnivorous animals. When hunting, snakehead does not chase, but hides near aquatic plants or other hidden objects, closely watching the movements around it. When it sees fish, shrimp, frogs and the like passing by, it quickly attacks and eats the prey.  

The growth speed of snakehead depends on the quality of the growth environment and the amount of bait food. Under natural conditions, the body length of a 1-winter-age fish can reach 19-39 cm, and the body weight can reach 100-750 grams; the body length of a 2-winter-age fish can reach 38-45 cm, and the body weight can reach 600-1400 grams. Under artificial rearing conditions, the body weight can reach 250 grams in the same year, and 0.5-1.0 kg the next year.

With the continuous development of the aquaculture industry now, snakehead aquaculture is becoming more and more widespread, but the cost of snakehead aquaculture is relatively much higher, while at the same time the profit it can return is also much greater. Investors can choose a scale and stocking quantity suitable for themselves according to their actual situation.