I. Timely stocking Huimin County Penaeus vannamei shrimp stocking time should be held in mid-May, can be stable in the pond water temperature above 20 Â°C is appropriate, the water temperature after June is 22-35 Â°C, the most suitable white shrimp Grow. In the case of long-term rainy days, special climates with low temperatures and low light levels, it is particularly important to have timely stocking.
Second, the stocking density of intensive culture ponds density of 30,000-40,000 / acre, good conditions for high-density intensive culture, should take the method of round catch, stocking density increased to 50,000-60,000 / acre. However, the density is too high to cause the size and size, the disease increases, floating head oxygen.
Third, the drug clear pond time to master the clear pond disinfection time, such as the seedbed in the application of quicklime, bleach powder has not yet disappeared after the drug on the Sheung Shui put seedlings, will cause calcium ions and chlorine ion harm shrimp seedlings, this is not according to the correct Due to the method of operation. Cultivation of ponds of Penaeus vannamei should be conducted in winter. For the old pool, 10-20 cm of silt should be removed, and about 15 days prior to shrimp release, 50-70 kg of lime/mu should be used, or 8 kg/mu of bleached water should be used to disinfect shrimp ponds. About 50 centimeters into the water from about 10 days before the release of the seedlings from the clear pond, the application of organic fertilizers and inorganic fertilizers to cultivate basic food organisms makes the water yellowish green or dark brown. The water transparency of the pool is kept at 25-40 cm and the pH is around 8.0.
Fourth, choose strong seedlings to choose quality shrimp is an important guarantee to improve the survival rate and high yield of shrimp. The stocking size of Penaeus vannamei is generally 1-1.2 cm. After desalinating to salinity of 1.5 â€°-2 Torr, shrimps are maintained in seedling ponds of 1.5 â€° salinity for 1-2 days to increase their ability to adapt to changes. . At this time, the shrimp seedlings have strong adaptability to the external environment, and the survival rate of the culture is high. If the specification is too small, the survival rate is low. However, the current specifications of shrimps of Penaeus vannamei are generally small, generally only 0.6 centimeters, and the survival rate is only about 35%, which can not achieve the purpose of high yield and high efficiency. When selecting shrimps of Penaeus vannamei, they should choose healthy and lively, slender body segments, uniform size, clean surface, full muscles, full bowel, sensitive to external stimuli, obvious direction when swimming, and transparent body The whole body has no lesions. The easiest way to distinguish between good and bad is to randomly take out some tail shrimp seedlings from the nursery pond and wrap the shrimp seedlings in a wrung wet towel. After 10 minutes, remove and put them back into the water. If the shrimp seedlings are still alive, it is good quality. Shrimp seedlings, otherwise poor quality seedlings.
V. Feeding and management In the entire breeding process of Penaeus vannamei, scientific management of pond water quality, feed, and daily work is required.
1. Regulation of water quality (1) Regulation of pond water color The ideal water color is yellow-green or dark brown formed by green algae or diatoms. In the pool, nitrogen fertilizer and phosphate fertilizer are applied proportionately. In the thin water pond, organic fertilizer should be applied in the early stage and timely fertilizer should be applied. In the middle and later stages of aquaculture, appropriate amounts of water are changed, a certain amount of quicklime is applied or beneficial microorganisms are applied, such as photosynthetic bacteria, EM, and Xifeili biologically active bacteria to control water quality. (2) Regulation of PH value and dissolved oxygen content of pond water The suitable pH value of P. vannamei is 7.8-8.5. PH value should not be too high, otherwise it will increase the toxicity of ammonia nitrogen and inhibit the growth of shrimp. In the early stage of cultivation, take an intermittent noon boot for 1-2 hours, then gradually increase the time for starting the aerator with the growth of the shrimp, and then start the machine for 24 hours at the middle and later stages of the cultivation to ensure that the pool of dissolved oxygen is maintained at 5 mg. / L. The dissolved oxygen in the bottom of the pond is above 3 mg/l.
2, science feed bait can choose full-rate palatable feed and small trash fish, snails and other categories. The amount of feed in the evening accounted for 50% of the daily feed. In the daytime, cast in the deep waters along the Yanchi beach, and cast them in shallow water in the evening. The principle is to finish eating within 2 hours after feeding.
3. The patrol ponds survey the pond three times a day at night, night and midnight, and use the light observation and fishing net inspection methods to check the activity and growth status of the shrimp. If there is abnormality, the amount of feeding should be adjusted. It is found that the floating head can start the aerator.
4, timely fishing from high temperature weather to choose sunny, do first increase oxygen, after the dynamic network. At the same time, it should be quick and staffing should be sufficient to minimize operational damage during capture. One-time capture in autumn should generally be noted that when the cold wave strikes, the sudden drop in temperature (above 8Â°C) will not allow shrimp to be harvested, and will be arrested after the temperature rises. High-yield intensive and nutritious shrimp ponds should adopt the method of round catching. When some shrimps grow to the commodity specifications, they will be picked up and harvested several times to make the white shrimp culture of South America achieve high yield and high efficiency.
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