Key Technical Points for High-Yield and High-Quality Freshwater Shrimp (Macrobrachium nipponense) Aquaculture
(1) Monoculture of freshwater shrimp in ponds. 1. Pond conditions: area of 5-10 mu, water depth of 0.8-1.5 m, firm and leak-proof pond embankments, slope of 1:(2-3), flat pond bottom slightly inclined toward the drainage outlet, and silt not exceeding 20 cm.
2. Preparation before stocking: ① Chemical pond clearing: 7-10 days before stocking, fill with 20 cm of water, apply 100-125 kg of quicklime per mu after slaking, and splash evenly over the entire pond for clearing and disinfection to remove wild fish and harmful organisms; ② Aquatic plant planting: species include Hydrilla verticillata, Potamogeton maackianus, etc., with the planting area accounting for 30-50% of the pond area, then fill with water and fertilize. 3. Water quality management: ① Use microbial preparations: such as EM bacteria, photosynthetic bacteria, etc. From late August to early November, use biological bacteria once every 15 days depending on the medication situation to improve the pond water environment. ② Microporous aeration: equip one 3 kW microporous aeration pump for every 20 mu, lay main pipes parallel to the two long sides of each pond, and install 6 disc-type microporous pipe discs with a diameter of 1.5 m per mu of pond. Dissolved oxygen should be above 5 mg/L. When dissolved oxygen in the shrimp pond falls below 5 mg/L, turn on the aeration pump. Aeration time is generally from 12:00 to 16:00 in the afternoon and from 24:00 at night to 6:00 the next morning, and should be extended on rainy or muggy days. 4. Feeding management: mainly feed complete compound feed for freshwater shrimp of different specifications at different stages, supplemented with rice bran and other feed in the early stage. Feed twice a day, with 1/3 in the morning and 2/3 in the afternoon. Adhere to the “four observations” (observe the season, observe the weather, observe the water color, observe feeding activity) and the “four fixeds” (fixed time, fixed location, fixed quality, fixed quantity). The daily feeding amount is 3-7% of shrimp body weight, and the specific feeding amount should be consumed within 2-3 hours. The feed coefficient for the whole season is 1.5-1.8. (2) Mixed culture of shrimp and crabs in ponds. There is no limit to the pond area, but generally no more than 50 mu is appropriate, with a water depth of 1.0-1.5 m. Pond clearing, disinfection, and grass planting are carried out according to the operating procedures for river crab culture. Stock 5-8 silver carp and bighead carp per mu, put in 200-250 kg of live snails per mu, and plant aquatic plants mainly including Hydrilla verticillata, Potamogeton maackianus, Elodea nuttallii, etc., with the aquatic plant coverage controlled at about 60%. During the growth period of young shrimp in autumn, apply fertilizer appropriately and feed a small amount of powdered feed. When using insecticides and disinfectants, avoid both the peak molting period of river crabs and the peak molting period of freshwater shrimp.