What is the specific method of grass shrimp culture?

1 shrimp pond \ x0d \ x0d \ 1. 1 seed selection pond \ x0d \ x0d should be built in an area with flat terrain, less silt, sufficient water, good water quality, no pollution and convenient water intake and drainage. It is suggested to use sediment with an area of 5 ~ 8 mu and a water depth of 2m, and each pond should be equipped with 2 ~ 3 2.2kW aerators. Mud and weeds in the old pond should be removed or ploughed and exposed at the bottom of the pond. \x0d\ \x0d\ 1.2 Cleaning and disinfection of the pond \ x0d \ x0d \ Soak the pond with 15 ~ 20 cm water 20 days before seeding, and choose pond cleaner to spread all over the pond to kill harmful microorganisms. In some newly dug ponds and some aging ponds with poor water exchange capacity, in order to prevent the explosive propagation of harmful algae in the middle and late stage of culture, attention should be paid to using algae removal drugs in advance, such as algae killing drugs and grass-catching drugs, to kill harmful algae at the bottom of the pond. \x0d\ \x0d\ 1.3 Purify the inlet water, adjust the salinity \x0d\ \x0d\ Wash and disinfect the shrimp pond before receiving water. When receiving water, use a 60-80 mesh filter to prevent harmful organisms from entering. After the water enters 80- 100 cm, it is necessary to disinfect the water body and kill the virus in the water body with powerful drugs such as bacterial toxins. At the same time, the pond was disinfected with a sprayer, and the drug concentration was appropriately increased. The salinity of the pond should be consistent with the desalted salinity of shrimp seedlings in the nursery. \x0d\ \x0d\ 1.4 fertilizer and water \x0d\ \x0d\ the use of shateli has a comprehensive effect. Once the shrimp is put into the pond, diatoms will be cultivated in 2 ~ 3 days. After the basic biological bait is cultivated, the seedlings are released after the water quality meets the following requirements. \x0d\ \x0d\ 1.4. 1 Visually, the color of the pool water has changed to yellow-brown or tawny, yellow-green, and the transparency is about 25cm. \ x0d \ x0d \ 1.4.2 Instrumentation: observe the microbial density with a microscope, and test various water quality indicators with a water quality analysis box, and release the seedlings after meeting the requirements. \x0d\ \x0d\ 1.5 aerator \x0d\ \x0d\ impeller aerator has the best effect and is located in the deep water of the pool. Within one month after sowing, the seedlings should be planted 1 time every day at noon and before dawn, each time for 2 ~ 3 hours. After one month, it will be turned on at noon and before dawn every day, 3 hours at noon and 10 hours before dawn. Increase startup time and frequency in rainy days. It should be turned on for at least 20 hours in the late breeding period. \ x0d \ x0d \ 2 shrimp seedlings \ x0d \ x0d \ 2.1selecting shrimp seedlings \ x0d \ x0d \ 2. 1. 1 Principles to be mastered when purchasing grass shrimp seedlings \ x0d \ x0d \ \x0d\ ② Seedlings cultivated without high temperature and abuse of antibiotics. \x0d\ \x0d\ 2. 1.2 shrimp seedlings should be uniform. The same batch of shrimp seedlings should be 1.0 ~ 1.2 cm in length, with clean body surface and strong vitality, and those with slender abdominal nodes are good seedlings. \x0d\ \x0d\ 2. 1.3 The two small antennae at the front end of a healthy shrimp are close together, and occasionally separate, but can be closed immediately. What can't be closed are poor shrimp seedlings. The tail fan of healthy shrimps is open. \x0d\ \x0d\ 2. 1.4 Healthy shrimps have "adherence behavior". If the shrimp is scooped up with a spoon, the strong shrimp will quickly swim to the side of the spoon and cling to the wall of the spoon. If you swim in the water, it is unhealthy shrimp seedlings. \x0d\ \x0d\ 2. 1.5 Take a number of shrimps with a body length of about 1cm from the nursery pond, bury them in a wet towel for 5 minutes, take them out and put them back into the raw water, which will be high-quality shrimps without affecting the survival rate. \x0d\ \x0d\ 2.2 Shrimp fry stocking \ x0d \ x0d \ 2.2. 1 The water body must be disinfected before the fry are released, so as to ensure that the water environment of the shrimp fry in the seedbed and the water environment of the culture pond are within a safe range. In addition, pay attention to the water test before stocking. After 1 ~ 2 days of water testing, shrimp seedlings can be released in batches without affecting the survival rate in the pond water environment. \x0d\ \x0d\ 2.2.2 Precautions for seedling release: ① The seedling release place should be on the windward side of the shrimp pond, not in the windward or shallow water. (2) Don't put the seedlings in bad weather. Seedlings should be planted at 8-9 am or at sunset in the afternoon on sunny days, not at noon. (3) Don't rush to plant seedlings until the pond is cleaned. ④ Don't put seedlings in shrimp ponds with bad water color and poor water quality. \ x0d \ x0d \ 2.3 stocking density \ x0d \ x0d \ sowing density should be between 8000 ~ 12000/ mu. Due to different pond conditions, the number of seedlings can be increased or decreased according to the actual situation. \x0d\ \x0d\ 3 Management in growing period \x0d\ \x0d "Raising shrimp is raising water" has become an experience. Maintain excellent water quality, so as to facilitate shrimp feeding and promote shrimp molting growth. \x0d\ \x0d\ 3. 1 water quality \ x0d \ x0d \ See the following table for the best range of water quality in grass shrimp culture ponds \ x0d \ x0d \ Bad adaptation range of the experimental project \ x0d \ \ x0d \ pH 8 ~ 9 is lower than 7.5 or higher than 9.5 \ X0d\. Dissolved oxygen (7 ~10) ×10-63x10-6 or 12 nonionic ammonia (NH3-n) (0.1~ 0.5 )×1. Hydrogen sulfide (0 ~ 0.2) ×10-60.6×10-6 or more \x0d\ nitrite (0.0 1 ~ 0.05) × 10-6 or more. \x0d\ ② There are fewer sunny days and more cloudy days. \x0d\ ③ There are few changes when there is wind, but many changes when there is no wind. \x0d\ ④ Change less big pools and more small ones. \x0d\ ⑤ Change the density less and change the density more. \ x0d \ 6 Change more or less if the biomass is too high, or change more if the water color is too strong and the transparency is less than 20cm. \ x0d \ 8 The water temperature changes slightly when it is lower than 20℃, but it changes greatly when it is higher than 32℃. ? x0d ⑨ The fishy smell of water should be completely replaced. If it can't be replaced, we should use "water quality improvement essence" and "fish and shrimp pond bottom cleaning" for comprehensive management. \ x0d \ When adding water or changing water, it should be drained before filling. Attention should be paid to the adsorption of chromium heavy metal poisons in ponds using well water. \x0d\ \x0d\ 3.3 Water color control and management in the growing period \ x0d \ x0d \ 3.3.1The so-called water color refers to the color of the pool water in the sun. The color of the water in the breeding period can be summarized as follows: \ x0d \ x0d \ ① The reddish-brown water mainly contains diatoms. It is the best water color for shrimp culture. \x0d\ ② Light green and emerald green water mainly contains green algae. Green algae can absorb a lot of nitrogen fertilizer in the water and purify the water, so prawns grow rapidly in green water. This water color is also the desired water color in aquaculture. \x0d\ ③ Dark green water mainly contains blue-green algae. Ponds are prone to aging. In this kind of water, prawns can still survive, but the incidence rate is high. \x0d\ ④ Dark brown and soy sauce-colored water mainly contains flagellates. It is easy to occur in aging ponds with improper feeding and deteriorated bottom material. Some flagellates can secrete paralytic neurotoxins, leading to shrimp poisoning and death. The abnormal management of this aquatic genus is mainly due to the excessive feeding of inferior bait and the increase of residual bait, which leads to the increase of dissolved and suspended organic matter and the proliferation of brown algae. \x0d\ ⑤ Yellow water mainly contains dinoflagellate. This water color is not suitable for shrimp and fish farming, but it is suitable for the growth of shellfish. Change the water immediately, increase the dissolved oxygen, and at least turn the water yellow and green. \x0d\ ⑥ Turbid water: mainly contains zooplankton or organic debris such as ciliates and clay particles. This water color is easy to make prawns sick, so pay attention to changing the water color. \x0d\ ⑦ The yellow turbid white water is caused by rain scouring the fine mud on the dike and entering the pond, which is not suitable for shrimp culture. \x0d\ ⑧ The clarified colored water has no phytoplankton due to lack of nutrients or heavy metal pollution, which is not conducive to shrimp culture. \x0d\ \x0d\ 3.3.2 Measures to change water color \x0d\ \x0d\ ① Increase water displacement and add disinfectant. \x0d\ ② Use shrimp or marine plant auxin to forcibly propagate beneficial algae and change water color. \x0d\ ③ Use Xiaduling or Zizyphus jujuba King to kill algae and disinfect, and water and fertilize after the expiration date. \x0d\ ④ Use prebiotic drug "Fish and Shrimp Savior" to improve the bottom of the pool. \x0d\ \x0d\ 3.4 Feeding \x0d\ \x0d\ 3.4. 1 Feeding amount is accurate and reasonable according to the physiological needs of prawns in each growth stage and the living conditions at that time. The daily feeding amount of grass shrimp (compound feed) is generally calculated according to the weight of each tail. 1g body weight, feed intake 16%, 2g body weight 14%, 3g body weight 12%, 5g body weight 10%, 8g body weight 8%, 15 ~ 20g body weight 6% ~ 20g. \x0d\ \x0d\ 3.4.2 Feeding principles According to the life habits of grass shrimp, the following principles should be mastered when feeding \x0d\ \x0d\ ① Feeding should be more and less, and should be even at a time. \x0d\ ② Feed more at night and less during the day. The feeding amount at night accounts for 65% of the whole day's feeding amount, and the feeding amount at day accounts for 35%. \x0d\ ③ Throw less in bad weather and more in good weather. \x0d\ ④ When the water temperature is higher than 34℃ and lower than 20℃, there is little or no investment. When the water temperature is 27 ~ 3 1℃, more water should be injected. \x0d\ ⑤ Less investment in poor water quality, more investment in poor water quality. \x0d\ ⑥ Use little or no drugs, and the feed can't be used if it is spoiled. \x0d\ ⑦ Don't throw it in windy weather, and throw less prawns when they molt a lot. \ x0d \ 8 Don't feed from 10 to 16 every day in hot season. \ x0d \ Increase the feeding amount by 20% on the first day after molting, and then feed normally. \ x0d \: Don't throw prawns when there is a storm, when the water quality is getting worse, and when they are floating. \x0d\ \x0d\ 3.5 disease prevention \x0d\ \x0d\ disease prevention, prevention first. Disinfect once every 0/5 days in the early stage, once every 0/0 days in the middle stage and once every 7 days in the late stage. Disinfect in time after heavy wind and rain, and disinfect in time if the water quality is abnormal. In addition: pay attention to patrol the pond regularly, observe the activities of shrimp, and deal with problems in time when found. \x0d\ \x0d\ There are many reasons why it is difficult to fundamentally solve the current shrimp disease. For example, farmers pay attention to environmental and water quality issues, ignoring the enhancement of shrimp immunity. Once shrimp disease is found, drugs are abused through hearsay. In addition, shrimp diseases caused by external factors are also varied. \x0d\ \x0d\ ① There is too much rainfall, more cloudy days, drastic changes in water temperature and excessive temperature difference. (2) sediment deterioration, harmful algae overgrowth. \x0d\ ③ The basic biological bait is insufficient, the synthetic bait has poor nutrition, does not shed its skin when it grows slowly, and its disease resistance decreases. \x0d\ ④ The environment is deteriorating and there are many pathogenic factors. \x0d\ ⑤ Extensive technical management and operation. \x0d\ ⑥ The released seedlings are unhealthy and have diseases, which brings difficulties to breeding. \x0d\ \x0d\ 3.6 Timely shrimp harvesting \x0d\ \x0d\ mainly focuses on shortening the shrimp culture cycle. Generally, after 80 ~ 90 days of culture, when the size of shrimp in the pond reaches about 40/kg, shrimp should be harvested in time to prevent losses caused by sudden temperature change.