(1) pond selection The choice of pond address requires sufficient water, good water quality, solid soil and convenient irrigation and drainage. The specific requirements are as follows: ① site selection. It is basically similar to the ponds of Macrobrachium and Macrobrachium. ② shrimp pond conditions. 0.13 ~ 0.2 hectares is suitable, and the water depth is1.2 ~1.5 meters, and the rectangle is better. The bottom of the pond is flat, and the slope of the pond is1.2 ~ 2.2. Each pond is equipped with equipment such as water pump and aerator. The water inlet is filtered with a mesh bag made of 60 ~ 80 mesh screen silk to prevent wild miscellaneous fish and fish eggs from entering the shrimp pond, and the water outlet is equipped with a dense mesh to prevent shrimp from escaping.
(2) Preparation before stocking
① Clear the pond. For the newly opened shrimp pond, water can enter as long as it is exposed for 2 ~ 3 days, while for the old pond, it needs dredging and exposure for one winter. Clean up the weeds near the pond and clean the pond strictly. Methods: Before the shrimp fry were released15 ~ 20 days, quicklime100 ~150 kg was used every 667 m ~ 2, and then the whole pond was sprinkled for disinfection.
② Cultivation of basic bait. After cleaning the pond for 7 ~10 days, before releasing the seedlings for 7 ~10 days, inject 50 ~ 60 cm of fresh water into the pond. Then, choose sunny days to apply fertilizer to cultivate biological bait in the pool. Fertilization can be applied with fermented organic fertilizer 1 00 ~150 kg or inorganic fertilizer every 667 m2, and 2 kg of urea or calcium superphosphate1kg should be applied every 667 m2, and the whole pool should be sprinkled evenly, and the inorganic fertilizer should be applied at the same amount every other day.
③ Transplanting aquatic plants. Transplanting a circle of Alternanthera philoxeroides or water spinach in the shallow water1~1.2 meters away from the pool, covering 20% ~ 25% of the water surface. Note: before transplanting Alternanthera philoxeroides, it is necessary to use10 ~15mg/l bleaching powder for detoxification.
(3) stocking fry
(1) seedling desalination. At present, most of the metapenaeus ensis fry used for breeding are produced in factories. Generally, the specific gravity of seawater for seedling cultivation is about1.015 ~1.020, so it must be domesticated before being moved to fresh water for cultivation. Therefore, the key to the success of freshwater aquaculture in metapenaeus ensis lies in the desalination of shrimp seedlings. Seedling manufacturers should be gradual in the process of desalination, and it is strictly forbidden to be eager for success and rapid desalination. Based on the analysis and summary of the production practice in recent years, shrimp seedlings can only be directly moved into freshwater ponds for culture after being diluted to a specific gravity of1.003 ~1.005, and generally the desalination time takes10 ~15 days.
② Seed quality. It is required that the seedling should be 0.7 ~1.0 cm long, with strong physique, strong bounce and clean and tidy appearance. The water temperature in the nursery pond should be close to that in the aquaculture pond, and the temperature difference should not be different by 3℃.
③ Number of seedlings released and stocking time. Shrimp fry with a body length of 0.7 ~1.0 cm are specially bred in metapenaeus ensis, and the stocking amount is 30,000 ~ 40,000 per 667 m 2. When mixed with fish, it is best to raise temporary seedlings, the body length is1.5 ~ 2.0 cm, and the stocking amount is generally 2 1 10,000 ~1.5,000 per 667 meters. If the density of fish ponds is high, it should be reduced according to the actual situation. Stocking time: the stocking time in Jiangsu and Zhejiang provinces is generally in the middle and early June of each year. According to the climate and water temperature, the southern Guangdong and Guangxi regions can be advanced appropriately.
(4) Feeding management: After the shrimps are released into the pond, it mainly includes water quality management, feeding management and daily management.
① Water quality management. The water quality of shrimp pond requires pH 7 ~ 8, dissolved oxygen not less than 4 mg/L, the water color is yellow green, and the transparency is controlled at 30 ~ 40 cm. 5 ~ 6 cm of water is added every 2 ~ 3 days in the early stocking period. Add it to the highest water level in hot summer season to keep the water quality fresh and stable. Change the water frequently at ordinary times to improve the water quality and ensure the fresh water quality during the whole breeding period.
② Feeding management. The shrimp larvae mainly rely on plankton in the pond as bait or supplemented with a small amount of fine particles within 1 month. After 1 month, the artificial compound bait (Macrobrachium macrobrachium feed) is mainly fed, and the daily feeding amount is generally 4% ~ 6%. In the growing season, some crushed snails, small miscellaneous fish, etc. will be added where conditions permit. The feeding amount should be flexibly controlled and adjusted in time according to the season, water temperature, climate and water quality. For example, when the water temperature is 25 ~ 30℃, metapenaeus ensis eats heavily. In order to ensure its rapid growth, we should seize the opportunity to feed more bait, and properly add 3% ~ 5% additives such as vitamins and bone meal to the feed to ensure the nutritional needs of shrimp growth. The principle of "small amount and multiple times" should be mastered in feeding with bait. Generally, the bait should be fed three to four times a day, and it is best to set up1~ 2 bait tables to check the feeding situation and ensure that no residual bait is left.
③ Daily management A. Insist on patrolling the pond in the morning and evening. Morning and evening patrol is one of the most important technical measures in shrimp pond management. The main contents include: (1) observing whether there is oxygen-deficient floating head, and finding that the floating head of shrimp should be filled with fresh water immediately or turned on to increase oxygen; When patrolling the pond, pay attention to check whether the net bag at the water inlet and the escape prevention net are damaged, prevent wild fish from entering the pond or shrimp from fleeing, and check the feeding, shelling and growth of shrimp. B. disease control. Adhere to the principle of prevention first, and sprinkle quicklime water regularly during the whole breeding period, generally every15 ~ 20 days with10 ~15mg/l limewater in the whole pond, so as to kill germs and drive away enemies, and at the same time supplement calcium, which is beneficial to the growth of shrimps. In addition, after 40 ~ 50 days of breeding, if the harmful organisms in the pond gradually increase, it is necessary to clear the pond in the medium term in time. Tea seed cakes or tea dregs can be used in ponds specially cultivated in metapenaeus ensis, and the dosage is 8 ~10g per cubic meter of water. When in use, they are mashed, soaked in water for10 ~12 hours, and their juice is sprinkled all over the pond, which can kill wild miscellaneous fish in the pond and will not affect the normal life and growth of metapenaeus ensis. C. keep a diary. During the breeding period, a file record management system should be established. Every day, the feeding amount, water temperature, water change and injection, and the feeding growth of shrimp should be recorded so as to find problems and take technical measures in time.
(5) The harvesting time of metapenaeus ensis mainly depends on the growth of adult shrimp and market demand. Generally, it can reach the commodity specification of 7 ~10 cm long if it is cultured in a freshwater pond for 80 ~100 days, and it can be caught by rotation. In southern Guangdong and Guangxi, according to local climatic conditions, shrimp can be cultured for two seasons a year, and the first season can be harvested from mid-July to early August, so that the shrimp in the next season can have enough incubation period. Common catching methods:
(1) the cage to catch. Usually put down the cage in the evening and close it the next morning. This method of collecting and catching can be listed one after another, and this method is mostly used in rotation assistance.
② Pull nets to catch shrimps. Catch shrimp in a shrimp pond with flat bottom with a net. Generally, the catching rate of three nets can reach 50% ~ 70%. According to the habit of shrimp's strong activity before dusk or dawn, and considering that it can be listed as early as possible, shrimp is usually caught at 8 ~10 in the evening, and the effect is better.
(3) release water from the dry pond to catch shrimp. When the water temperature drops below 15℃, the prawns basically stop eating and growing. After fishing by the above two methods, catch the remaining prawns in time. The fishing method is to release water for dry pond fishing.
The content of this article comes from: China Biotechnology Development Report by China Agricultural Publishing House.