Technical points:
(1) stocking mode
The mixed culture mode of tilapia and Penaeus vannamei (in which Penaeus vannamei adopts the mode of first release, second release and third release), and the specific stocking density and mode are shown in table 1. The stocking time of tilapia is from the end of March to the beginning of April.
Table 1 new ecological model of mixed culture of tilapia and Penaeus vannamei
Tilapia stocking density (tail/mu) Tilapia stocking specification (body length) (cm) Shrimp stocking density (10,000 tail/mu) Shrimp stocking interval (days) Shrimp specification (cm) Tilapia yield per mu (kg) Shrimp yield per mu (kg) Net profit (yuan/mu) 2 1 .7 ~ 2.2 minutes Three times of stocking: .0 is released 20 days earlier than tilapia, 70-80 days earlier, 60-65 days earlier 1.5-2.01.7-2.2. The first release of seedlings is 2.0, and the second release of seedlings1.5 is released 20 days earlier than tilapia, 70-80 days earlier/.
① Preparation before stocking: after harvesting fish and shrimp at the end of the year, drying the pond. Disinfect the pond before stocking. There are two methods: dry pond cleaning and pond cleaning with water. One is dry pond cleaning. After finishing the pond, only 8 ~12 cm deep water is left at the bottom of the pond, and 4 ~ 5 kg/mu of tea bran or 50 ~ 80 kg/mu of quicklime are sprinkled on the whole pond. After three days of exposure, the water is returned, and the injected water is filtered through a 40 ~ 60 mesh to remove impurities. The second is to clean the pond with water, and sprinkle bleaching powder (about 30% available chlorine) in the whole pond, with the dosage of 20g/m3; Or 80 ~100 kg/mu of quicklime per meter of water depth. Before stocking the seedlings, the seedlings can be released only after "testing the water" and confirming that the toxicity disappears.
(2) Feeding: feed mainly with compound feed, supplemented by cake and bran. The daily feeding amount is 3% ~ 5% of the total weight of the fish in the early stage, and 2% ~ 3% of the total weight of the fish in the later stage, and feed/kloc-0 each time in the morning and afternoon. Pay attention to the feeding situation, increase or decrease the feeding amount according to the weather change, stop feeding on rainy days or when the fish floats, and there is no need to feed Penaeus vannamei specially.
③ Daily management: pay attention to patrol the pond every morning and evening to observe the fish's feeding situation and water quality changes. Water injection every 1 5 ~ 20 days1time, and the water injection times may be increased according to the situation in high temperature season. Keep the transparency of the pool water about 30 cm. When the water color is strong, you can spray quicklime to adjust the water quality, and the dosage is15 ~ 20 kg/mu. Every 2 ~ 3 mu of water surface is equipped with 1 aerator, and it is turned on 1 time every afternoon and early morning, each time for 2 ~ 3 hours, and it is turned on 24 hours in high temperature season. (3) arrest
Determine the time of fish leaving the pond according to the requirements of fish leaving the pond. When the water temperature drops to 15℃, all tilapia should be caught. The prawns are caught in cages. After reaching the market standard, they are caught irregularly according to the market demand. (4) Economic benefit analysis
The compound farming model of tilapia and Penaeus vannamei can reduce the farming risk and improve the farming efficiency in the pond. Taking the breeding benefit as the evaluation index, stocking Penaeus vannamei seedlings every 60-80 days and stocking three batches can effectively improve the economic benefit of tilapia-Penaeus vannamei mixed culture mode, which is 50% higher than that of single tilapia.
Suitable area: The coastal area suitable for tilapia culture requires a certain salinity (5 ~10).
Precautions: when stocking tilapia fry, the water temperature should be stable above 20℃; Penaeus vannamei was stocked 20 days earlier than tilapia.