Essentials of Culture techniques of Penaeus Monodon

Although the domestic market price of Penaeus Monodon fluctuates too much, the profit of culture is still considerable, with an annual profit of 12000 yuan / mu. It is one of the excellent alternative species of Penaeus vannamei, □ / Nanjiang Biotechnology Co., Ltd., Hainan Province. Xu Anmin Wang Ping Li Yijun Penaeus Monodon (Penaeus monodon Fabricius) is commonly known as grass shrimp and tiger shrimp, which belongs to Arthropoda, Crustacea, soft crustacean and True soft Nail in classification. Decapoda, Cladospora, Penaeidae, Penaeus. In China, it is mainly distributed in the coasts of Taiwan, Hainan and Guangdong, and less and less to the north. Its large body, fresh and tender meat, rich nutrition, high temperature resistance and dry resistance, suitable for the sale of fresh shrimp, high price, has become an important breeding object in many countries and regions. This paper mainly introduces the author's exploration of the culture technology of Penaeus Monodon in high pond in recent years, which can be used as a reference for Penaeus Monodon farmers. First, shrimp fry release 1.1 preparation work from release to harvest of shrimp, the whole cultivation stage takes only a few months, and the preparation work includes draining the stagnant water in shrimp ponds, storage ponds and ditches, cleaning the bottom of ponds, repairing dams, cleaning ditches, removing silt and pest, filtering into water, breeding basic bait, purchasing seedlings, transportation and so on. The above work time is strong, the workload is heavy, need to be closely linked, earnestly and steadfastly do a good job. The dredging and drying ponds of shrimp ponds are the main link of healthy breeding, and the ponds must be cleared thoroughly. After the shrimp is harvested at the end of each year, drain the pond water, seal the gate and dry the pond until the bottom of the pond is cracked, then move the residual bait, sundries and silt to the outside of the embankment, use quicklime 70-100kg per 667m2, distribute it evenly on the bottom of the pond, and then plough and rake the bottom of the pond for ploughing exposure. 1.2Aquaculture water prepared for aquaculture was filtered by sand filter wells. About 100-120cm was added 15 days before seedling release, and then the water was disinfected with 5-10g/m3 chlorine preparation. After 2 days, fertilizing in sunny morning was selected to cultivate basic bait, and organic fertilizer combined with dolomite powder 15kg could be selected for fertilizer and water per 667m2. After that, topdressing was carried out every 3-5 days according to the water color and planktonic biomass of the pond to ensure that there were abundant basic food organisms. Use less inorganic available fertilizers, because inorganic fertilizers start water quickly but are difficult to maintain. Whether the biological culture of basic food is proper or not directly affects the growth rate and survival rate of stocked shrimp seedlings. The best color of shrimp pond is light brown. 1.3 the selection of shrimp seedlings requires uniform size, strong vitality, good reverse swimming ability, smooth body surface without attachment, body length above 1.2cm, two small tentacles with v-shaped bifurcations at the front end of the first antennae often close together, and the body segments are sparse and long. Preferably the black shell seedling of p12-p18, there are 4-6 thorns on the forehead of the shrimp seedling. Shrimp seedlings should also be tested for virus and vibrio, and should not carry several specific pathogens such as WSSV, TSV, IHHNV and IMNV, and the number of vibrio should be controlled within a safe range. 1.4 the first generation of shrimp seedlings can be released from late March to early April, choose sunny weather, the water temperature is more than 25 ℃, 2 hours before release, the oxygenator should be turned on to stir up the water, and stress products such as VC and glucose should be put in at the same time. When releasing the seedlings, try to avoid stirring the pond water. First, put the seedling bag into the pond and soak it for 20 minutes, so that the water temperature in the bag is close to that in the pond (the temperature difference is not more than 3 ℃). Put the seedlings downwind where the water is deeper in the upwind, and the difference in salinity between the shrimp fry pond water and the shrimp pond water is less than 5 ‰. The second plant can be released in mid-July. The seedling density should be determined according to the conditions of shrimp ponds, water environment and management level. Second, the feeding management depends on the seedling density to determine the feeding times. The author mostly chooses four times a day for 60,000 / mu. Due to the change of daily water quality, he chooses more meals during the day and less in the morning and evening. This can not only meet the growth needs but also stabilize the water quality. 2.1 Feed selection generally choose high quality compound feed for feeding. High-quality formula feed not only provides sufficient protein and amino acids to ensure the normal growth of shrimp, but also is beneficial to the digestion and absorption of shrimp. However, the selection of bait should not only take the protein content as the standard, but the stable quality as well. The author broke the convention in practice and raised grass shrimp with white shrimp feed for three consecutive years, without any negative effect. 2.2 feeding frequency in the early 7 days, two meals a day, once in the morning and afternoon, 100000 0.5kg/, supplemented by feeding Fengnian worms, once a day; 8-15 days, three meals a day, at 6:30, the amount of feed was 30%, 40%, 12, 00, 40%, 19, 100, 30%, 30%, 30%, 40%, 30%, 30%, 30%, 30%, 30%, 40%, 19, 00, 30%. After 16 days, 4 meals were fed at 6:30, 11:30, 17:00 and 22:00 (20%, 30%, 30% and 20%, respectively). 2.3 the daily feeding amount of baiting skills should be flexibly mastered according to the weather, water quality, health and activity of shrimp, etc. It is difficult to measure the material through the observation net in the first 40 days, generally the following meal inspection bait table does not leave residual bait as the principle, it is better to eat within 2.5-3 hours after feeding, and it is better to master the material within 1-1.5 hours in the middle and later stage. When the weather is muggy or there are thunderstorms, it can be fed less or not, which can reduce the feed coefficient and reduce the pollution to the water body. Improve the immune ability and anti-stress ability of shrimp. Third, keeping good water conditions for culture can ensure the normal appetite of Penaeus Monodon, reduce the feed coefficient and improve the growth rate. the main means of water quality management is to monitor the physical and chemical factors and biological factors of culture pond water and sediment regularly, and the indexes that change rapidly are monitored daily. The pH value can be used as an index of the quality of pond water, and the daily fluctuation is less than 0.5 in the middle and later stage of culture. The content of dissolved oxygen measured before 6:00 should not be lower than that of 4mg/L. It is most suitable to control the salinity of shrimp ponds between 15-25 ‰. The salinity is too low, the shrimp shell is thin, there are too many blue individuals and are prone to parasites; the salinity is too high, the shell thickness and molting frequency are low and the growth is slow. The total alkalinity is more than 100mg/L, the content of nitrite is lower than that of 0.02mg/L, and the content of ammonia nitrogen is lower than that of 0.3mg/L. 3.2 the timely regulation of water color is a comprehensive reflection of the quality and quantity of plankton in the pond water. How to maintain a good water phase is directly related to the success or failure of culture. In the ponds where prawns are cultured, the ideal water color should be yellowish green or tea brown formed by green algae or diatoms. In the later stage of culture, the water can be changed appropriately according to the following circumstances, so that the transparency of the pond water can be controlled at 35-45cm. Another situation is that cyanobacteria water often appears in the later stage, and algal blooms are prevalent, and the water will become thicker and thicker. During this period, some drugs that can inhibit or kill cyanobacteria should be used selectively, and the effect of changing water will be better combined with the change of water. 3.3 improving the pond bottom and rational use of beneficial microorganisms is the bottom culture for Penaeus Monodon, and the bottom habitat habit of Penaeus Monodon is more obvious, so the bottom quality directly determines the success or failure of culture, which is very important for the treatment of sediment. Using beneficial microbial preparation to culture shrimp is a major breakthrough in shrimp culture technology, and it plays an important role in improving the sediment. For the use of beneficial microorganisms, we should pay attention to the following points: ① should be used regularly, adding beneficial microbial preparations every 7-10 days before seedling release, continuous use can reduce the accumulation of organic matter in the pond and bring convenience for later management. ② insists on using high-quality biological products, such as Nuobiqing water purifier, oxidant, ammonia nitrate and other compound microbial agents can effectively improve the bottom of the pool, reduce H2S, ammonia nitrogen and nitrite, etc., the dosage per 667m2 is 15-20g. The growth and reproduction of ③ microbial preparation needs certain conditions, such as dissolved oxygen, light, certain carrier, etc., and its use effect is also different under different conditions, so it is very important to grasp the conditions for use. 3.4 ensuring sufficient dissolved oxygen in water is the primary condition for shrimp survival, which not only affects the feeding rate, feed utilization rate and weight gain rate of shrimp. When the dissolved oxygen is insufficient, the physical and chemical conditions of the water environment are poor and the physique of shrimp decreases, which can lead to the outbreak of some epidemics and the death of hypoxia in severe hypoxia, resulting in great losses in shrimp culture. Therefore, it is very beneficial to the healthy growth of shrimp to create a three-dimensional oxygen enrichment model and to use liquid and solid oxygen enhancers irregularly to maintain sufficient oxygen enrichment. The amount of dissolved oxygen in shrimp pond water should be higher than that of 3mg/L. In order to ensure sufficient dissolved oxygen in the process of culture, we should reasonably turn on the aerator and use oxygen enhancers such as hydrogen peroxide and calcium peroxide according to weather, water quality, sediment and hydration conditions, so as to keep sufficient dissolved oxygen in shrimp ponds (especially at the bottom of the pond). Fourth, disease control because there are many diseases in the growth process of Penaeus Monodon, the key to the success or failure of shrimp culture lies in the prevention and control of shrimp diseases, we must adhere to the principle of "prevention first, comprehensive control". Due to the pollution of culture water, climate change and the decline of seedling quality, there are many kinds of diseases of Penaeus Monodon. The common diseases are as follows: 1. There are a large number of ciliates (bell worms, branch worms, constrictors, etc.) on the body surface of ciliated shrimp. The disease is very easy to occur in water with a lot of organic matter. When a small amount of immobilized ciliates attach to the shrimp, the symptoms are not obvious, and there are no pathological changes in shrimp. However, when a large number of insect bodies are attached, the appearance of the gills, body surface and appendages of shrimp is black, and the body surface is gray-black as fluffy. The diseased shrimp floats on the water surface in the morning, reacts slowly, does not feed, does not molt, growth is blocked, and is easy to cause other complications. The main harm of ciliosis is that it affects the respiration of shrimp and is more likely to die in large numbers under the condition of low dissolved oxygen. The main reason is the excessive fertilizer of water quality and the mass reproduction of bell worms, branch worms, condensed worms and so on. Treatment: 1. Drain 20-30cm, use zinc sulfate powder 0.75-1g per cubic body of water once a day, use twice in severe cases, add fresh sea water to restore the water level in 36 hours, and transfer water and fertilizer water 4 days later. 2. Tea bran 10-15g/m3, while adding lime 5-10g/m3, combined with water exchange effect will be better. 3. Pay attention to the regulation of salinity, low salt water is more likely to breed ciliates. 2. White spot syndrome shrimp floats on the surface of the water, swims slowly, the body color is reddish, and there are slightly pinkish white spots on the carapace on the body surface. The size and shape of white spots are irregular, and they are most likely to appear on the head and chest armour of prawns. In severe cases, the whole head and chest armour turns white. Secondly, the carapace surface on the back of the abdomen and leukoplakia on both sides had no obvious change, but lost transparency. Prevention methods: florfenicol 3 ‰, vitamin C5 ‰, vitamin E5 ‰, yeast 5 ‰, brown sugar 10 ‰ for 5-7 days. Note: it is strictly forbidden to drain and irrigate water, it is strictly forbidden to stimulate shrimp stress by disinfection, and daily feed is reduced by half. In the later stage, shrimp collection should be arranged in time to reduce losses, and attention should be paid to isolation so as not to infect the surrounding shrimp ponds. 3. Baculovirus disease is caused by MBV baculovirus infection, which causes destruction of hepatopancreas, whitening, atrophy or swelling and decay of shrimp. Diseased shrimp anorexia, not peeling, carapace easy to peel and opaque, slow growth, no special disease appearance, about a month of young shrimp is easy to be infected, the mortality rate is as high as 100%. Prevention and treatment: with leukoplakia syndrome. 4. when red Gill and black Gill disease suffer from long-term hypoxia or weak body and poor resistance, if the Gill tissue is damaged, it is easy to be infected by bacteria, which makes the Gill turn red and black. under the microscope, it can be seen that there is dendritic red pigment in the Gill and local diffuse necrosis of the Gill filament. the more serious the disease is, the darker the color is, the worse the vitality of the diseased shrimp is, but it can still feed normally. Prevention and treatment: take 3 ‰ florfenicol for internal administration, and disinfect it with chlorine dioxide for 3 times continuously, once a day. Drain 20% of the water level before disinfection, replenish water to the original water level 2-3 days after disinfection, and use microbial preparations to adjust the water quality. 5. The soft shell disease shrimp carapace becomes softer, the body is thin, the activity is weakened, and the growth is slow, which can lead to death in severe cases. The disease may be caused by excessive organic matter in water, low pH value and long-term undernutrition. Prevention and treatment methods: add new water, improve water quality, sprinkle with 5kg/667m2 lime and water, increase the pH value of water, and feed high quality compound feed. Take active calcium and vitamin C internally, strengthen calcium supplement, promote shelling and strengthen physique. 6. The blue-bodied shrimp has a blue body and a thin carapace, and the individuals in this appearance are particularly intolerant of beating at harvest, thus reducing economic benefits. The specific reason is unknown, and most of them tend to be caused by nutritional imbalance. Treatment: external use: sprinkle 2-3g/m3 calcium hydrogen phosphate regularly in the whole pool. Oral administration: vitamin E + vitamin C + yeast + brown sugar, 1 meal a day for 7 consecutive days. 7. Muscle necrosis disease shrimp emaciation, muscle atrophy and separation from the carapace. At the beginning of the disease, leukoplakia appeared on the back of the abdomen, and then the whole abdomen became white, Gill and muscle necrosis, and finally died. The incidence rate is 2-3%. The mortality rate in the transportation of live shrimp is extremely high, even as high as 90%, which greatly affects the price. The cause is unknown and the disease is not caused by a biological venereal disease. Treatment: 1, aquaculture ponds in high temperature season to prevent water temperature is too high or sudden change, should often change water, maintain a certain water level and sufficient dissolved oxygen. 2. Oral administration: florfenicol 3 ‰, vitamin C5 ‰, vitamin E5 ‰, yeast 5 ‰, brown sugar 10 ‰ for 5-7 days. Fifth, the low temperature tolerance of harvested Penaeus Monodon is poor, and it is not suitable to spend winter along the coast of the South China Sea, especially in the season with large temperature fluctuation between autumn and winter, so the harvest time should be strictly grasped. It is mainly based on the health of pond shrimp, molting condition, sediment, water quality, production arrangement and other factors. Once the abnormal activity of prawns is found, it should be picked up in time, and it is usually ideal to be listed around the New year's Day. Shrimp collection is mostly carried out at night, using electric trawl or push net to collect shrimp. Since the late planting in 2006, the author has achieved success in five consecutive cropping, and the average yield per mu has increased steadily, from the original 300kg to the present 500kg, and the highest yield per mu is 612kg. Most of the specifications are 80-100s / kg. Although the market price of grass shrimp fluctuates too much, the profit of breeding is still considerable. The average profit per mu can be maintained at about 12000 yuan in several years, and the highest profit per mu can reach 21000 yuan.