Freshwater aquaculture such as Penaeus vannamei and other seawater species, using sea crystals to adjust pool water integrated ions,
The yield and output value can be greatly increased. The input-output ratio is very high. It is considered that the species of the white shrimp of the genus Penaeus is sea salt and salt, and in the process of desalinating to pure freshwater breeding, the survival rate of the diluted culture will be low, the clam shell will be relatively difficult, and the merchandise will be cracked. The softness and taste of the shrimps are characterized by soil odor and relatively low market prices. For this reason, in the production practice, the author made use of concentrated sea crystal and fresh water to imitate natural seawater to make a technical breakthrough in the inland purewater culture of white shrimp.
First, the sea crystal and its application Sea crystal is a product of seawater and salt chemical industry, mainly produced by a series of processes such as evaporation, centrifugation, and concentration of seawater or brine. It basically retains the main components of seawater and is concentrated seawater. The selective addition of trace elements can not only supplement some of the elements and compounds lost during the production process, but also make the entire product more practical, such as the addition of selenium, molybdenum, etc., not only promoting the growth of aquatic animals, but also making it More healthy, nutritious, and comprehensive development.
At present, apart from being used as industrial raw materials, Sea Crystal is more successful in fishery applications: First, it is used in estuaries or in low-salinity areas for shrimp or crab breeding or cultivation. Second, artificial seawater is prepared in inland lake areas for seawater seed breeding. Third, it is widely used in recreational fisheries such as inland aquariums for seawater demand. However, due to the fact that people's awareness is still at the initial stage of research and development, it has not been widely applied in production. The Penaeus vannamei seedlings must go through a gradual desalination process when they enter freshwater aquaculture. Generally, they require a time of 7 days to 10 days to achieve satisfactory results. Many nursery farms are located on the beach, and the supply of fresh water is relatively lacking. Therefore, most of the assaults faded for 3 days to 4 days, and the salinity dropped to 3‰ to 5‰. As a result of the sharp drop in salt, on the one hand, the osmotic pressure inside and outside the shrimp larvae has not been effectively regulated; on the other hand, the larvae entering the external water environment are unable to adapt to the rapidly changing water bodies and die. Even if the ponds are forced to die, they will die. The entire shrimp production has been reduced or failed.
Second, the sea crystal shrimp larvae lethal test According to the characteristics of the sea crystal, targeted sea crystal + freshwater on the South American white larvae larvae survival test. Samples were taken on the 8th day of the larvae at the nursery of Hanting District, Weifang City, Shandong Province. The salinity of the nursery ponds was desalinated to 15 预先 in advance. The test water was prepared from pure fresh water and seawater. The conditions were room temperature, not inflated, and daily. Sewage is sucked once, and 20 shrimps live on each day for bait and living water use.
The test results show that the adaptation ability of Penaeus vannamei to salinity mutations is at the cut-off point of 6‰, and the survival rate is less than this value, and the 24-hour mortality rate in freshwater is 100%.
Third, the use of sea crystals and effects For actual production, in 2002 ~ 2003 two years, the author of more than 20 farmers conducted technical guidance and tracking services, and pure freshwater aquaculture and coarse salt and sea crystal test Made a comparison. Although both are primary products of seawater, crude salt has the following disadvantages compared to sea crystals: First, some elements or compounds have been lost with the vapor in the sea salt formation process, and there is a lack of nutrients suitable for the growth of shrimp. Second, coarse salinized water tends to form a “layered†phenomenon in relatively closed or less wind freshwater aquaculture ponds, ie, salt water is underneath, fresh water is on, and there is a clear boundary between salt and fresh water, affecting the photosynthesis and adversely affecting shrimps. Grow.
From the comparison of production feedback, in the pure freshwater culture of Penaeus vannamei, the use of sea crystal is adjusted to 15‰ to 18‰ in the early stage of planting, and then gradually reduced to 6‰ and maintained as appropriate. The survival rate of culture can be greatly increased. If sea salt is returned to about 20 用 using sea crystals 15 to 20 days before the product is out of the pond, products with a marine flavor can be obtained, and the shells will be hard and fresh, and the listed price will increase exponentially to obtain the best economy. benefit.
IV. Analysis of benefits and prospects At present, the price of sea crystal is 0.3 yuan to 0.35 yuan/kg, which will be used on a large scale in freshwater, and the increase in production costs will be relatively small, which will not result in a significant increase in farming costs. It is estimated that the salinity will be increased to 28 æ¯ per cubic meter of freshwater, and the use of sea crystal will be only 2.9%, or 29 kilos, and the amount of sea crystal will be 8.7 8.7 yuan/cubic meter. In the preparation of 6-inch salinity, only 0.6% of liquid sea crystal is needed, and the cost is not more than 0.2 yuan/m3. Even if the loss is added after use, the cost of sea crystal is around 0.3 yuan/cubic meter. The survival rate of shrimp can be increased by 30% to 50%, and the yield and output value can be increased by 1 to 1.5 times.
Sea Crystal is inexpensive and easy to use. It is an environmentally friendly product. After use, it can effectively remove freshwater frogs and other predators, and it can effectively suppress the growth of water clouds and weeds, and improve the quality of aquatic organisms. It is indeed worth promoting.
The yield and output value can be greatly increased. The input-output ratio is very high. It is considered that the species of the white shrimp of the genus Penaeus is sea salt and salt, and in the process of desalinating to pure freshwater breeding, the survival rate of the diluted culture will be low, the clam shell will be relatively difficult, and the merchandise will be cracked. The softness and taste of the shrimps are characterized by soil odor and relatively low market prices. For this reason, in the production practice, the author made use of concentrated sea crystal and fresh water to imitate natural seawater to make a technical breakthrough in the inland purewater culture of white shrimp.
First, the sea crystal and its application Sea crystal is a product of seawater and salt chemical industry, mainly produced by a series of processes such as evaporation, centrifugation, and concentration of seawater or brine. It basically retains the main components of seawater and is concentrated seawater. The selective addition of trace elements can not only supplement some of the elements and compounds lost during the production process, but also make the entire product more practical, such as the addition of selenium, molybdenum, etc., not only promoting the growth of aquatic animals, but also making it More healthy, nutritious, and comprehensive development.
At present, apart from being used as industrial raw materials, Sea Crystal is more successful in fishery applications: First, it is used in estuaries or in low-salinity areas for shrimp or crab breeding or cultivation. Second, artificial seawater is prepared in inland lake areas for seawater seed breeding. Third, it is widely used in recreational fisheries such as inland aquariums for seawater demand. However, due to the fact that people's awareness is still at the initial stage of research and development, it has not been widely applied in production. The Penaeus vannamei seedlings must go through a gradual desalination process when they enter freshwater aquaculture. Generally, they require a time of 7 days to 10 days to achieve satisfactory results. Many nursery farms are located on the beach, and the supply of fresh water is relatively lacking. Therefore, most of the assaults faded for 3 days to 4 days, and the salinity dropped to 3‰ to 5‰. As a result of the sharp drop in salt, on the one hand, the osmotic pressure inside and outside the shrimp larvae has not been effectively regulated; on the other hand, the larvae entering the external water environment are unable to adapt to the rapidly changing water bodies and die. Even if the ponds are forced to die, they will die. The entire shrimp production has been reduced or failed.
Second, the sea crystal shrimp larvae lethal test According to the characteristics of the sea crystal, targeted sea crystal + freshwater on the South American white larvae larvae survival test. Samples were taken on the 8th day of the larvae at the nursery of Hanting District, Weifang City, Shandong Province. The salinity of the nursery ponds was desalinated to 15 预先 in advance. The test water was prepared from pure fresh water and seawater. The conditions were room temperature, not inflated, and daily. Sewage is sucked once, and 20 shrimps live on each day for bait and living water use.
The test results show that the adaptation ability of Penaeus vannamei to salinity mutations is at the cut-off point of 6‰, and the survival rate is less than this value, and the 24-hour mortality rate in freshwater is 100%.
Third, the use of sea crystals and effects For actual production, in 2002 ~ 2003 two years, the author of more than 20 farmers conducted technical guidance and tracking services, and pure freshwater aquaculture and coarse salt and sea crystal test Made a comparison. Although both are primary products of seawater, crude salt has the following disadvantages compared to sea crystals: First, some elements or compounds have been lost with the vapor in the sea salt formation process, and there is a lack of nutrients suitable for the growth of shrimp. Second, coarse salinized water tends to form a “layered†phenomenon in relatively closed or less wind freshwater aquaculture ponds, ie, salt water is underneath, fresh water is on, and there is a clear boundary between salt and fresh water, affecting the photosynthesis and adversely affecting shrimps. Grow.
From the comparison of production feedback, in the pure freshwater culture of Penaeus vannamei, the use of sea crystal is adjusted to 15‰ to 18‰ in the early stage of planting, and then gradually reduced to 6‰ and maintained as appropriate. The survival rate of culture can be greatly increased. If sea salt is returned to about 20 用 using sea crystals 15 to 20 days before the product is out of the pond, products with a marine flavor can be obtained, and the shells will be hard and fresh, and the listed price will increase exponentially to obtain the best economy. benefit.
IV. Analysis of benefits and prospects At present, the price of sea crystal is 0.3 yuan to 0.35 yuan/kg, which will be used on a large scale in freshwater, and the increase in production costs will be relatively small, which will not result in a significant increase in farming costs. It is estimated that the salinity will be increased to 28 æ¯ per cubic meter of freshwater, and the use of sea crystal will be only 2.9%, or 29 kilos, and the amount of sea crystal will be 8.7 8.7 yuan/cubic meter. In the preparation of 6-inch salinity, only 0.6% of liquid sea crystal is needed, and the cost is not more than 0.2 yuan/m3. Even if the loss is added after use, the cost of sea crystal is around 0.3 yuan/cubic meter. The survival rate of shrimp can be increased by 30% to 50%, and the yield and output value can be increased by 1 to 1.5 times.
Sea Crystal is inexpensive and easy to use. It is an environmentally friendly product. After use, it can effectively remove freshwater frogs and other predators, and it can effectively suppress the growth of water clouds and weeds, and improve the quality of aquatic organisms. It is indeed worth promoting.