Brief introduction of greenhouse Culture of Penaeus vannamei in Longhai

In recent years, various places have tried winter shed culture, and combined with local culture conditions, to explore a suitable local successful culture model. Because of its superior geographical advantages, Longhai has become one of the main areas of shrimp culture in winter sheds in China, and its culture model is representative. It can be used for reference □ / Fuzhou Dafu Feed Co., Ltd. Yangyongquan Penaeus vannamei is tropical shrimp, the suitable water temperature range is 15-32 ℃, stop feeding when the water temperature drops to 18 ℃, and die when the water temperature is below 12 ℃. In order to cope with the cold weather, the greenhouse is generally used for shrimp culture in the southern coastal areas in winter. As the Lunar New year falls in January and February each year, the temperature is low, the number of live shrimp is small, and the demand is large, so the price of shrimp is often particularly high. Therefore, raising prawns in greenhouse has become the main mode of Longhai in winter. The insulation shed generally uses miscellaneous wood, steel wire and nylon film as the main materials, which is not only strong, transparent, heat preservation, but also can reduce the cost. The greenhouse culture of Penaeus vannamei has the characteristics of weak light, less air exchange, lower water temperature, longer culture cycle (generally one month longer than that of summer shrimp) and less enemy damage, and has strong technology. especially the control of water quality and the prevention and control of diseases in the middle and later stages is the key to determine the effectiveness of greenhouse shrimp culture. According to the characteristics of greenhouse culture, some current problems of farmers are analyzed. Combined with production practice, the author summarizes the techniques of cultivating Penaeus vannamei in Longhai greenhouse as follows for reference. Pond conditions and greenhouse construction 1. Pond conditions the pond for greenhouse culture of Penaeus vannamei should not be too large, and it is difficult to cover the greenhouse if the pond is too large. Generally, the suitable culture area is 3-5 mu. The pond is mostly rectangular, the ratio of length to width is 5:3, the depth of the pond is about 2m, the water depth can be maintained about 1.1m-1.5m, and there is a perfect inlet and drainage system. 2, greenhouse construction greenhouse should not be built too high, too high wind shield capacity is poor, and waste of materials, herringbone bottom edge and pool edge close. The greenhouse is built into a herringbone scaffolding, like a house, with a herringbone length and width exactly the length and width of the pool. The greenhouse uses Cunninghamia lanceolata wood and steel wire rope to build a pile frame and a supporting grid frame, which is covered with plastic film, and then pulls and presses the steel wire rope in the vertical direction of the supporting grid frame to form a maintenance network of the plastic film flat state; the steel wire rope is fastened to the short wooden piles arranged around the pond foundation, and the intersection of the supporting grid and the two wire ropes that maintain the network is then tied up and fixed with iron wire to form a closed thermal insulation system covering the whole pond. The end diameter of Cunninghamia lanceolata wood is more than 6cm, the distance between pillars is 1.2 m, the diameter of steel wire rope is 2.4mm, the tensile strength 1570Mpa, the sum of breaking force 5.52KN, the arrangement distance of steel wire rope of supporting grid is 0.5m, and the perpendicular spacing of wire rope of network is 1.0m, and the plastic film is made of polyethylene film. The top and bottom of the film is made of polyethylene mesh with the same diameter as the pond 2.4mm, with a mesh size of 10 × 10cm, to fix the film to prevent it from being blown off by the wind. The construction of the greenhouse is mostly completed in October or early November. The shrimp pond is equipped with a 1 kilowatt aerator per mu to prevent hypoxia in the later stage of culture. Before releasing shrimp fry, the pond must be cleaned to adjust the water quality before releasing Penaeus vannamei fry. 1. Clear the pond (1) flush the bottom of the pond: wash away the organic humic silt and saline-alkali and metal deposits caused by bacteria; (2) fully bask in the pond: kill bacteria and mineralized organic matter. (3) to remove weeds in pond base. (4) Lower quicklime: 100-150 kg of quicklime per mu is sprinkled in the whole pool. If the pond is alkaline, quicklime cannot be used. In addition, the amount of quicklime can be adjusted according to the pH of the pond soil. 2. Most farmers use groundwater to enter Longhai, and some of them pump river water. Those who pump groundwater do not need a filter, while those who pump river water go through the filter. The filter screen is a double-layer screen with 80 mesh in the inner layer and 200 mesh in the outer layer. When pumping, it should be changed frequently to avoid blockage. The filter screen can filter out wild miscellaneous fish, worm eggs and so on. 3. Water disinfection generally uses bleach (available chlorine 30%) 30ppm. The effect of disinfection is to reach the bottom of the water without any plankton. 4. Water quality must be adjusted before releasing seedlings, so as not to affect the survival rate of shrimp seedlings. Ph 7.8-8.6, alkalinity 80-200ppm, calcium ion > 300ppm, magnesium ion > 300ppm, no ammonia nitrogen and nitrite, dissolved oxygen > 4.0ppm, transparency