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Penaeus vannamei is a major highlight of aquaculture in recent years and its market prospects are promising. In particular, after the success of the desalination trials, Guangdong's Doumen and Xinhui began to set off an upsurge of breeding white shrimps in South America from last year. Through the actual understanding of the first line of production in the past two years, the author summarized the experience of a great deal of success and failure in the breeding of Penaeus vannamei, and reviewed a large number of literature on Penaeus vannamei, summarizing the early work on the stocking of Penaeus vannamei. The technical elements are described below:
Selection and transportation of shrimp
The selection of quality shrimp is the key to the success of shrimp farming. Only the purchase of robust shrimp without pathogenic pathogens, especially those without virus (current detection of mainly vitiligo and taura virus), In order to ensure the smooth progress of the breeding work. At present, shrimps from Doumen and Xinhui are mainly from Hainan and Zhanjiang, so they must go to the shrimp farms with good water quality and high reputation to purchase shrimp. Observed with the naked eye, healthy shrimp has the following characteristics: strong shrimp vigor, swimming has obvious directional, very sensitive to external stimuli, smooth and transparent body surface, muscles are not cloudy, body without lesions, especially large touch whip No redness, no yellowing of the ankle, no blackness, fullness of the bowel and no turbidity.
During transportation, it should be ensured that the shrimp seedlings are not deprived of oxygen, and the seedling density depends on the length of transportation time, shrimp seedlings specifications, water quality and water temperature and other factors. It is usually transported by oxygen in a polyethylene bag with a length of 70 cm and a width of 37 cm. Within 10 hours of transportation, the temperature of the water is between 18-26°C. The size of the shrimp is between 0.8-1.0 cm. When good, it can hold about 1500 bags per bag.
Clear pond disinfection and backwater
Penaeus vannamei has a higher requirement for substrate quality, and excessive organic matter at the bottom of shrimp ponds can easily cause death of white shrimp. According to experts' determination, ammonia-nitrogen concentration in shrimp ponds is below 0.5ppm, nitrous acid-nitrogen concentration is below 0.1ppm, dissolved oxygen is above 5ppm, and hydrogen sulfide concentration is kept below 0.1ppm. Therefore, excessive silt must be removed, and 150 kg of quicklime should be added to the improved aquifer immediately after dredging. It is best to be exposed to the sun for a period of time. After clearing the entire pond, all enemy organisms, competition organisms and some substances that may carry pathogens that are not conducive to shrimp farming must be removed before the shrimps are released. At the same time, it is also necessary to use a non-seepage plastic woven cloth in the corner of the shrimp pond to form a separate water surface for the purpose of cultivating shrimp and dilute it.
Backwater must be sieved and filtered to prevent the entry of sundries and some predator organisms. The return water must be strictly sterilized. Generally, quicklime, bleaching powder, bleaching powder, sodium dichloroisocyanurate, hydantoin, and dioxide are used. Chlorine, quaternary ammonium salts, and iodine-containing salts can all serve their purpose.
Desalination and Aquaculture
Although Penaeus vannamei can grow in freshwater, it differs from the technical parameters required for freshwater shrimp. During the seedling period, the salinity in the shrimp pond must be similar to the desalination of shrimp in the shrimp farm. At present, the shrimp can be generally diluted to 6‰-10‰, and can be sold. After entering the shrimp pond, it must be gradually diluted. It is best to use it. In 10-15 days, it is diluted to 1‰-2‰. The time is too short and the growth of the shrimp will be hindered; the pH value should be kept in the range of 8.0-8.6 during the larval period.
Penaeus vannamei also has high requirements for basic baits, and the adequacy of basic baits is an important factor for the success of white shrimp aquaculture, especially at the seedling stage, within one month after planting (generally 0.98-1.0 cm when released). The length is generally 3-4 cm. This period basically feeds on basic bait. The cultured water is yellow green or light brown. The fertilizer used is divided into organic fertilizer (chicken, pig, cow droppings) and inorganic fertilizer (fertilizer). When the organic fertilizer is put, the organic fertilizer is first crushed, dried and fermented and then packed in a fiber bag. Each bag is about 10 kg. Mu with 3 bags, scattered hanging in the pond, to the withdrawal of the color when the thick can be removed; application of inorganic fertilizer, the general urea 1-1.5 km / acre, compound fertilizer 2 kg / acre. The time for cultivating basic bait varies depending on the weather and water temperature. In early spring, the photoperiod is short, the water temperature is low, and the growth and reproduction of plankton are slow. The cultivation time is usually 10-20 days. After May, the water temperature rises and culture The time is generally 7-10 days. Once the water color is thickened, it is the best time to put the shrimp seedlings. The long incubation time will adversely affect the growth of the shrimp seedlings. When cultivating basic bait, it can be beneficial to prevent disease if some complex beneficial bacteria strains can be placed to form dominant bacteria in the water body.
Pre-release precautions
1. The seedlings should be placed on the sunny days around 10 o'clock in the morning or in the evening. Rainy days and sundays should not be planted at noon;
2. Each shrimp pond should be full of shrimp seedlings at one time to avoid the occurrence of "Kung-sun shrimp" and affect the production efficiency;
3, stocking density can not be too high, should be based on the actual situation of shrimp ponds, generally 4-55,000 / acre;
4, shrimp should be placed in the wind, and the whole bag of shrimp should be soaked in the shrimp pond first half an hour, until the bag water temperature and the pool water temperature is generally the same before the release.
Penaeus vannamei is one of the three fine shrimp species with the highest production of shrimp produced in the world. It is mainly distributed in the waters of the Pacific coast of the Americas, and is located in the northern part of Peru to Sonora, Mexico, and is most concentrated on the coast of Ecuador. The suitable growth temperature is 18-32°C. Below 16°C, the activity drops and the growth stops. The optimum temperature is 23-30°C. The temperature begins to drop below 9°C and begins to die. The suitable salinity for growth is 2‰-40. ‰ 最 最 最 最 最 最 最 最 ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰ ‰.