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What technical measures should be taken for artificial nursery?
1, broodstock: The use of brooding broodstock (number depending on the amount of seedling requirements) in the vicinity of the test site a salinity of 4.62 ‰, the water temperature of 23 - 25 °C captured in the brackish white prawn, will capture the selection The broodstock was temporarily stored in a cage for a day in brackish water where the original broodstock lived. The average tail weight of the broodstock was 2.56g, the average body length was 5.52cm, and the absolute amount of fledgling was 1100 grains/tail. 2, broodstock desalination: As the capture of the broodstock living water salinity is relatively high, and the salinity of the test water is relatively low, if the broodstock directly into the test water, broodstock can not adapt to death, so The broodstock must be gradually diluted to allow it to live in the tested low salinity waters. After the broodstock was temporarily stored in the cage for one day, the diseased and dead shrimp was removed, and the broodstock was quickly transported to the test site with a metal tank with aeration equipment. The pre-prepared water body had a salinity of 4.60 ‰ and a water temperature of 25°C. A few 200L ordinary tanks were inflated and then gradually diluted with fresh 0.6 ‰ freshwater broodstock, and a salinity gradient was decremented every 24 hours. When the water body salinity dropped to 2.00 ä¸å†, it was no longer desalinated. Broiler hatching: After the four cement pools are cleaned in advance, the submersible pump is used to inject water from the water quality cultivation tank. The water in the water quality culture tank is the enriched fertilizer containing water floating in the algae and injected into the water in the nursery pond. Mesh filtration through 160 mesh was required. The salinity of the water entering the nursery pond was 2.08 Torr, the water temperature was 23--26°C, and the pH was 7.5. The desalinated broodstock was placed in a cement tank cage and aerated with oxygen. Feed the bait on the second day. The feed is a pellet feed and chopped shrimp, crab and shellfish, etc. Each shot is made every morning and evening. It is advisable to finish the day. The newly hatched Z-shaped larvae have an average body length of 1.86mm. The third abdomen section of the abdomen of the body is bent to the ventral surface and suspended in the water. The head is downward and the tail is upward. With the help of the three pairs of feet and feet, the upper and lower movements are performed. There are bounce movements from time to time, with phototaxis, but often avoid direct sunlight or strong light. 4, larvae bred: larvae bait to be suitable for growth of larvae, generally with soy milk, egg yolk and Artemia nauplii. In the newly hatched Z-shaped larvae, there are still some residual yolks in the cephalothorax, and depending on their own nutrition, they start to feed after 1 to 2 days. Therefore, the larvae must be fed on the second day after hatching. The number of pre-feeding should be more, feeding 4 to 5 times a day, and each time in the late morning, evening and evening. The egg yolks to be fed should be wrapped in a 120-mesh sieve and then kneaded into an egg yolk suspension. Just as with soy milk, the whole pool should be splashed. The daily amount of egg yolk and soymilk should be 10 to 20 ppm. With the growth of larvae, the amount of feeding should gradually increase. The Artemia nauplii was only added after the development to the third stage, and the feeding amount was 1.5-20000/m3. It was better to supply 4-6 shrimp per tail. Breeding ponds continue to increase oxygen, the water temperature is controlled between 22--28°C. The water temperature is too high. Cover the pool top with black polypropylene mesh. Observe and record the larvae's metamorphosis, eating conditions and activities every day. Pay attention to water temperature, water color and salt. Changes in pH and pH, timely adjustment of water physicochemical factors. After 15 days of incubation, the larvae became metamorphosed by seven clam shells. The average body length of the juvenile shrimp was 5.63 mm. The swimming posture was reversed from the Z-shaped larval period to swimming in the horizontal direction. Swimming ability is greatly enhanced and activities are agile. At this point you can go out of the pool and place the seedlings.