Cultivation techniques of Penaeus vannamei
1, ecological characteristics.
Penaeus vannamei is a tropical shrimp. The survival water temperature is 6-40℃, the growth water temperature is 15-38℃, and the optimum growth water temperature is 22-35℃. The adaptability to low temperature is slightly poor. When the water temperature is lower than 15℃, the feeding activity is affected and it dies below 9℃. The shrimp has strong resistance to environmental changes, can grow in water with salinity of 0.5 ‰-3.5 ‰, and can be cultured in pure fresh water after desalination. Dissolved oxygen should be above 5 mg/L, and the minimum tolerance is 1.2 mg/L. The adaptive range of pH value is 7.0-8.5, and the contents of ammonia nitrogen and nitrite should not be too high.
2. Desalination measures.
Before planting seedlings, enclose a certain area with film or colored cloth in the corner of the pond, with a water depth of about 50 cm. Then, the salinity of the water is adjusted to be similar to that of the nursery with bittern or coarse salt. According to our practice, the salinity difference is adjusted to 1 ‰ according to 50 kilograms of raw salt per 60 square meters of water surface, and then the purchased shrimp seedlings are put into temporary cultivation, and after natural desalination for 7- 10 days, the surrounding film or colored cloth is removed for normal cultivation.
3. stock trading.
The stocking time of Penaeus vannamei is generally from mid-May to mid-July. Wide: Generally, seedlings are released every 667 square meters 10000- 15000 plants, and the yield is about 100 kg. Intensive cultivation: about 30 thousand seedlings are planted every 667 square meters, and the output is about 200 kilograms.
4. Feeding time and quantity.
Feeding Penaeus vannamei twice a day at 8: 00 am and 20: 00 pm; Feeding three times a day in the middle period of culture: 8: 00 am, afternoon 19, and 23: 00 pm; In the late stage of culture, they were fed four times a day: 7: 00 am, noon 12, afternoon 19, and 0: 00 pm. The feeding amount is 8%-10% of the previous shrimp weight; 6%-8% in the medium term; Late 4%-5%. Evenly spread on the edge of the pond, and the feeding amount at night accounts for 50% of the daily feeding amount.
5. Adjust the water quality.
The water color of Penaeus vannamei pond is yellowish brown. The transparency is controlled at about 30 cm in the early stage of aquaculture and at about 40 cm in the later stage. During the breeding period, fermented chicken, pig and cow dung are topdressing 1 time per week, and the dosage is 2.5-3.5 kg per 667 square meters.
6. Disease control.
Once Penaeus vannamei gets sick, it is very difficult to treat it, and prevention should be the main method. The main methods are as follows: Dibromohydantoin compound disinfectant is used every 10- 15 days 1 time, and the dosage is 0. 1g/m3, and sprayed evenly in the whole pool; Treatment: use dibromohydantoin compound disinfectant 1 time, and the dosage is 0.2g/m3. For patients with serious illness, use 1 time after changing water slightly every two days, and the dosage is 0. 1g/m3.
7. Harvest and fishing.
The breeding period of Penaeus vannamei is 65-80 days, and the specification is 60-70/ kg, which can be put on the market for sale. Fishing method, can use shrimp cage net fishing, or dry pond fishing