2. Drain the pond water 1 month before disinfection, continuously expose the pond bottom 15 ~ 20 days, and spray the whole pond evenly with bleaching powder 15 ~ 20kg with chlorine content of 25% ~ 28% per mu for disinfection. After disinfection, filter seawater with a 0.25mm sieve, soak it in water for 2-3 days, drain the pool water, and soak it repeatedly for 2-3 times, and the water depth after cleaning the pool is 30-50cm. Every 2 ~ 3 days, 0.5 ~ 1g urea and 0. 1 ~ 0.5g calcium superphosphate are used as basic feed for culture, so that the water color is light brown, which is beneficial to the growth of Meretrix meretrix.
3. The breeding period of breeding varieties is in early summer, which varies with varieties and regions. The spawning period in Liaoning, Shandong and other places is July-August. June-July in Jiangsu, Zhejiang and Fujian; Guangdong and Guangxi are from May to July. The sea surface temperature during the spawning period of Meretrix meretrix is about 27℃ ~ 29℃, and the optimum temperature for embryo development is 24.9℃ ~ 365438 0.4℃, and the optimum temperature is 26℃ ~ 28℃. The suitable environment for the survival of Meretrix meretrix seedlings is that the sediment concentration is at least 75_, and the total sediment concentration is the best. The seedlings have strong adaptability to low specific gravity seawater.
4. In the process of daily management, we should always check and remove pests in time. Fish can be mashed with 5 ~ 8 kilograms of tea seed cake per mu, soaked in water and evenly sprinkled on the surface; Enemies such as crabs and snails can be removed with nets or hands. When storing water and raising mussels in the reclamation area, it is necessary to prevent the damage of the filter screen. You can use night lights to trap fish, shrimp, crabs and other harmful organisms in the water or drain the pool water regularly to drive and catch them. First, the water level is lowered to 20 ~ 30cm, then the pool water is splashed with bleaching powder. After 6 ~ 10 hours, filtered seawater is introduced for dilution, then water is released, and it is washed repeatedly by tides for 2 ~ 3 times. Pay attention to the change of water color when storing water and raising mussels in reclamation areas. On sunny days, apply 0.5 ~ 1g urea to every cubic meter every 2 ~ 3 days to keep the water light brown.
5. The seedling water for disease control must be treated by precipitation, sand filtration and ultraviolet sterilization, or the whole pool is sprayed with bleaching powder for disinfection. Using 0.5 mg * mycin/L to control diseases in the process of culture can inhibit the proliferation of seedlings and is beneficial to the development and growth of young clams. Therefore, antibiotics such as chloramphenicol, sulfamethoxazole, furazolidone or oxytetracycline should be put into every cubic meter every day in the process of juvenile mussel culture to inhibit bacterial reproduction. When hybridomas are attached to the surface of young shellfish, 2 ~ 4 grams of furazolidone per cubic meter can be used to control the proliferation of hybridomas. Or spraying 4-6 grams of penicillin or streptomycin into the bait pool per cubic meter, can also achieve good disease prevention effect.