CATDOLL : CATDOLL: Will the fry of the rosenbergii shrimp be eaten by the pomfret?

Will the fry of the shrimp be eaten by the Pomfret?

Yes. The fry of the shrimp is one of the three most farmed shrimp species in the world and will be eaten by the tilapia. The tilapia is a tropical fish of the order Perciformes. It is the main farmed species in my country and is an omnivorous fish. It will eat effective fish or shrimp fry.

How to co-culture tilapia with white shrimp?

The mixed culture model of tilapia and white shrimp can effectively overcome the shortcomings of tilapia price fluctuations and shrimp diseases and high risks. After promoting the tilapia-white shrimp compound culture model by using the principle of fish and shrimp mixed culture technology, the average tilapia yield per mu in Zhuhai Pingsha Tilapia Breeding Base was 1,630 kg, a year-on-year increase of 28%, and the total output value of fish and shrimp was 66 million yuan (of which the output value of tilapia was about 53 million yuan and the output value of white shrimp was about 13 million yuan), a year-on-year increase of 31%, the total profit of fish and shrimp was about 18 million yuan, and the average profit per mu was 3,300 yuan. The net income of each household generally reached 20,000 to 50,000 yuan.

Technical points:

(1) Free-range model

The mixed culture mode of tilapia and Penaeus vannamei (where Penaeus vannamei adopts the mode of one-time stocking, two-time stocking and three-time stocking), the specific stocking density and method are shown in Table 1. The stocking time of tilapia is the end of March and the beginning of April.

Table 1 New ecological model of polyculture of tilapia and Penaeus vannamei

Tilapia stocking density (tilapia/mu) Tilapia stocking size (body length) (cm) Shrimp stocking density (10,000 tilapia/mu) Shrimp stocking interval (days) Shrimp size (cm) Tilapia yield per mu (kg) Shrimp yield per mu (kg) Net profit (yuan/mu) 2 800 1.7-2.2 Stocking in three times: 1.5 for the first stocking, 1.0 for the second stocking, 1.0 for the third stocking. Stocking 20 days earlier than tilapia, 70-80 days apart, 60-65 days apart. Stocking 1.5-2.0 1 831 105 2 5642 800 1.7-2.2 Stocking in two times: 2.0 for the first stocking, 1.5 for the second stocking. Stocking 20 days earlier than tilapia, 70-80 days apart, 60-65 days apart. Stocking 1.5-2.0 1 822 97 2 2542 800 1.7～2.2 One-time stocking: stocking quantity 3.5 20 days earlier than tilapia 1.5～2.0 1 799 89 1 966 (2) Main management measures

① Preparation before stocking: After harvesting fish and shrimp at the end of the year, the pond is dried. Before stocking, the pond is disinfected. There are two methods: dry pond cleaning and pond cleaning with water: one is dry pond cleaning. After repairing the fish pond, only 8-12 cm of water is left at the bottom of the pond. 4-5 kg/mu of tea bran or 50-80 kg/mu of quicklime are sprinkled on the whole pond. After 3 days of sun exposure, the water is returned and the injected water is filtered through a 40-60 mesh net to remove impurities; the second is pond cleaning with water. The whole pond is sprinkled with bleaching powder (about 30% effective chlorine) at a dosage of 20 g/m3; or 80-100 kg/mu of quicklime is sprinkled on the whole pond for every meter of water depth. Before stocking seedlings, "test the water" to confirm that the toxicity has disappeared before stocking.

② Feeding: mainly compound feed, supplemented with cake meal and bran. The daily feeding amount is 3% to 5% of the total weight of the fish in the early stage, and 2% to 3% of the total weight of the fish in the later stage. Feed once in the morning and afternoon. Pay attention to the feeding situation, increase or decrease the feeding amount appropriately according to weather changes, stop feeding on rainy days or when the fish float to the surface, and do not need to feed the white shrimp specially.

③Daily management: Patrol the pond every morning and evening to observe the fish's feeding and water quality changes. Add water once every 15 to 20 days. In hot seasons, the frequency of water injection can be increased depending on the situation. Keep the water transparency of the pond at about 30 cm. When the water color is dark, sprinkle quicklime to adjust the water quality. The amount is 15 to 20 kg per mu. Equip one aerator for every 2 to 3 mu of water surface. Turn it on once in the afternoon and early morning every day for 2 to 3 hours each time. In hot seasons, it should be turned on 24 hours a day. (3) Catch

The time of fish removal from the pond is determined according to the fish removal specifications. When the water temperature drops to 15°C, all tilapia should be caught. The shrimp are caught in cages and when they reach the market specifications, they are caught and put on the market irregularly according to market demand. (4) Economic Benefit Analysis

The tilapia-vannamei composite farming model can reduce farming risks and improve the farming efficiency of ponds. Taking farming efficiency as the evaluation index, stocking vannamei fry every 60 to 80 days, for a total of three batches, can effectively improve the economic benefits of the tilapia-vannamei mixed farming model, which is 50% higher than that of tilapia alone.

Suitable areas: Coastal areas suitable for tilapia farming require a certain salinity (5-10).

Note: When stocking tilapia fry, the water temperature should be kept above 20℃; whiteleg shrimp should be stocked 20 days earlier than tilapia.

(1) Main management measures

① Preparation before stocking: After harvesting fish and shrimp at the end of the year, the pond is dried. Before stocking, the pond is disinfected. There are two methods: dry pond cleaning and pond cleaning with water: one is dry pond cleaning. After repairing the fish pond, only 8-12 cm of water is left at the bottom of the pond. 4-5 kg/mu of tea bran or 50-80 kg/mu of quicklime are sprinkled on the whole pond. After 3 days of sun exposure, the water is returned and the injected water is filtered through a 40-60 mesh net to remove impurities; the second is pond cleaning with water. The whole pond is sprinkled with bleaching powder (about 30% effective chlorine) at a dosage of 20 g/m3; or 80-100 kg/mu of quicklime is sprinkled on the whole pond for every meter of water depth. Before stocking seedlings, "test the water" to confirm that the toxicity has disappeared before stocking.

② Feeding: mainly compound feed, supplemented with cake meal and bran. The daily feeding amount is 3% to 5% of the total weight of the fish in the early stage, and 2% to 3% of the total weight of the fish in the later stage. Feed once in the morning and afternoon. Pay attention to the feeding situation, increase or decrease the feeding amount appropriately according to weather changes, stop feeding on rainy days or when the fish float to the surface, and do not need to feed the white shrimp specially.

③Daily management: Check the pond every morning and evening to observe the fish feeding and water quality changes. Add water once every 15 to 20 days, and increase the frequency of water injections depending on the situation during the hot season. Keep the water transparency of the pond at about 30 cm. When the water color is dark, sprinkle quicklime to adjust the water quality. The amount is 15 to 20 kg per mu. One aerator is installed for every 2 to 3 mu of water surface. Turn it on once in the afternoon and early morning every day for 2 to 3 hours each time. It should be turned on 24 hours a day during the hot season.

(2) The time of catching shall be determined according to the fish size requirements. When the water temperature drops to 15℃, all tilapia should be caught. The catching of shrimps shall be done by cage catching. When the shrimps reach the market size, they shall be caught and put on the market irregularly according to market demand.

(3) Economic Benefit Analysis Tilapia-white shrimp compound culture model can reduce the risk of culture and improve the culture efficiency of ponds. Taking culture efficiency as the evaluation index, stocking white shrimp fry every 60 to 80 days, for a total of three batches, can effectively improve the economic benefits of tilapia-white shrimp mixed culture model, which is 50% higher than that of single tilapia culture. Suitable areas: Coastal areas suitable for tilapia culture require a certain salinity (5 to 10).

This article is from: China Agricultural Press "China Biotechnology Development Report"