Few diseases in mixed culture of fish and shrimp

1 area and variety of mixed culture

The total area of mixed culture of Penaeus vannamei with milkfish and male tilapia is 400 mu. A total of 330000 lice fry were cultured, including 200mu of Penaeus vannamei mixed with milkfish, 120mu of Penaeus vannamei mixed with male tilapia, and 80mu of pure milkfish as control.

(2) work before throwing seedlings

Clean the pond, dry the pond and disinfect the pond according to the routine before releasing the seedlings. Enter sea water in time, fertilize and cultivate basic bait.

(3) the amount and period of seedling

The number of seedlings released can be determined according to the pond conditions, the level of management and the specific conditions of the aerator. In pure lice fish ponds (control ponds), an average of 2000 fish fry were released per mu, and an average of 20000 Penaeus vannamei fry and 850 coarse fry were released per mu. The seedlings of Penaeus vannamei were released in mid-April. The milkfish was released on May 15.

4 Water quality management

Add water regularly, mainly fresh water. According to the change of water color, fertilize or change water properly to keep the water color yellowish green, green or yellowish brown, so that the water is rich in microbial bait, but not too thick.

(5) do a good job of bait feeding

In the process of mixed culture of male tilapia and prawn, only shrimp feed was used, and milkfish and tilapia mainly ate shrimp residual bait, shrimp excreta and various benthos and algae. However, a small amount of shrimp feed was also developed, and the feed coefficient of shrimp was 1.3.

6. Do a good job in disease prevention.

In the process of breeding, disinfect and apply water quality improver regularly. The specific method is to sprinkle 50kg with quicklime and 25mg/kg tea bran water per mu 15 days before seedling release. After sprinkling and killing miscellaneous fish, remove the shrimp with permethrin, and then enter the sea water to 60~70cm fertilizer water. In the whole culture process, disinfection and water purification were carried out every 15 days, and bait was given at the same time.

7 timely harvest after 100 days of cultivation, Penaeus vannamei reached the commercial specification of 60 per kilogram and began to be harvested by power grid. the high-yield ponds reached 225kg per mu, the low-yield ponds reached 100kg per mu, the average yield per mu was 140kg, the price per kilogram was 15 to 16 yuan, and the output value per mu ranged from 3, 000 to 7, 200 yuan. Milkfish and male tilapia remain in ponds and continue to be cultured until 120-150 days after harvest, which can produce about 500kg per mu. The survival rate is 90%, and the pure culture reaches 1000kg per mu.