The highlights of the healthy culture of white prawn
2018-04-20 15:01:05
Penaeus monodon, commonly known as grass shrimp, ghost shrimp, bamboo shrimp, etc., is a warm water shrimp, is the world's three largest aquaculture breeding area and production of shrimp cultured varieties. Penaeus monodon is characterized by large individual size, rapid growth, short husbandry cycle, wide salinity range, omnivorous, high temperature resistance, high yield, long lived transportation, and high selling price. China's South China coast has been widely promoted in recent years. In order to promote the healthy development of the monoculture of squash, the shrimp prawn farming technology is introduced as follows for reference.
I. Ecological habits of Penaeus monodon
Penaeus monodon is inhabited by sand or mud sediments. It usually does not move during the day, and it has the strongest appetite in the evening and starts frequent foraging activities. Its adaptation to salinity ranges from 5 to 25, and the closer it grows to 10, the faster it grows. The suitable temperature range is 14°C to 34°C, and the optimum growth water temperature is 25°C to 30°C. When water temperature is lower than 18°C, feeding is stopped. If the water temperature is not lower than 12°C, it will not die. Strong omnivorous, the requirements for feed protein is 35% to 40%, shellfish, miscellaneous fish, shrimp, peanut bran, wheat bran, etc. can be fed. The maximum body length of P. monodon captured in the natural sea area is up to 33 cm and the body weight is between 500 and 600 grams. Shrimp cultured in ponds for 80 days to 100 days, body length up to 12 cm to 13 cm, body length growth of 0.1 cm to 0.15 cm per day, weighing about 25 grams. Each kg of shrimp up to 40 to 60, generally yields 100 kg to 200 kg per mu, can be raised in two years.
Second, shrimp pond construction
Shrimp tanks should be constructed in areas near the mid-high tide line where winds and waves are small, tides are smooth, beaches are flat, water is clear, and there are no sources of pollution. Sandy bottom is the best, and sand and mud bottom are the second. The general tidal range should be between 2 and 3 meters, and the duration of orgasm should not be less than 3 hours. The salinity of seawater should be 10 to 20, and the pH should be 7.8 to 8.5. Shrimp pond rectangular, length, width ratio of 2:1 to 4:1, along the inlet channel for "non-" arrangement. Shrimp pond area of ​​0.7 square kilometers to 1.0 square kilometers is good, the pool depth of 2.0 meters, water depth of 1.5 meters, the bottom of the pool should be flat, drain bottom is less than the bottom of the pool 30 cm to 40 cm, easy to drain pool water. Each shrimp pond should have independent entrance and exit gates. Three gates are provided on the gates of the inlet and outlet gates. The middle slot is used to install the gates, and the gates are installed inside and outside the slots. The slot width is 6 cm and the distance between the three slots is 0.6 to 1.0 meters for operation and management. Where conditions permit, water storage sedimentation tanks can be constructed according to 1/3 to 1/2 of the shrimp pond area. High-level pools should be constructed not far from the sea area, easy to pump water, clean and stable water quality, sandy bottom, and fresh water sources.
Third, clear pond disinfection
The dredging and drying ponds in shrimp ponds are the main link in healthy farming and must be thoroughly cleared. After the shrimps are harvested at the end of each year, the pool water is drained and the sun is sealed at the gates. It is sun dried until the bottom of the pond cracks, and then the residual bait, debris and silt are transported to the outside of the embankment, where they are ploughed and exposed. It is best to lay a layer of 10cm thick clean sand on the bottom of the pool to improve the shrimp pond bottom. In the new shrimp pond, the gate should be opened to allow the sea water to enter and rinse out, so that the pH value at the bottom of the pond can be stabilized at 7.5 or more to allow the shrimp to be released. About 20 days before stocking, a 60-mesh sluice net was installed, and clearing ponds were sterilized with drugs. First, 50 kg to 100 kg of lime were sprinkled per acre, then 20 cm of water was poured, and 0.2 ml of chrysanthemum was sprayed to dilute the water. After 3 days drain the water and rinse twice. Re-inlet water 30 cm and then soaked with tea bran 15 kilograms of water for 24 hours, even the slag Quanchiposa. Drugs should be applied evenly to any place in the pool for thorough disinfection.
Fourth, training basic food
Within 10 days to 20 days after the shrimps are stocked, the main foods are planktons, copepods, diatoms and other planktons, so the cultivation of basic food organisms is an important technical measure to improve the survival rate and growth rate of shrimp seedlings. After the tea bran is applied for 2 days to 3 days, 80 cm to 100 cm of water is poured, 2 kg of urea is applied per acre, and 0.2 kg of phosphate fertilizer is applied. After that, dressing is applied once every 3 days to 4 days, and the dosage is reduced by half so that the transparency of the water reaches 40 cm. ~ 60 cm. The pH value is between 8.0 and 8.5. The water color is yellow-green or green. The fertilizer can be released after 6 days to 10 days. If it is not possible to put the seedlings in time, the Feitang time reaches 20 days or more and the water quality becomes old. The six-shrimp shrimp (Ctenopharyngodon idellus) reproduces again, and it is necessary to re-drain, and the drug is used to kill the six-skrust shrimp, and then the influent fertilizer is applied to cultivate the basic bait. .
Fifth, put the shrimp
Shrimp seedlings require uniform individual size, robustness, strong vitality, good reversal ability, smooth surface without attachments, body length 1.2 cm or more, the first tentacles diverge in front of the V-shaped two small tentacles often close together, body section Sparse and long. P12-P18 black shell seedlings are preferred, and 4 to 6 spikes have been found on the forehead of the shrimp. The density of seedlings shall be determined according to the conditions of the shrimp ponds, the water environment and the management level. General shrimp pond water depth of 1.2 meters, 0.800 to 10,000 per acre put seedlings; water depth of 1.6 meters, 10,000 to 13,000 per acre Fangmiao. Conditional shrimp farms can increase the density of shrimp, and 20,000 to 40,000 mu can be planted. No. 1 can be planted from late March to early April. To select sunny weather, when the water temperature is stable above 25°C, plant the seedlings. When laying seedlings, the seedling bag is first immersed in the pool for 20 minutes so that the water temperature in the bag is close to the water temperature in the pool (the temperature difference does not exceed 3°C). The seedlings in the deeper places where the water is deeper are placed in the wind, and the shrimp and seedling pool water and the shrimp pond water The difference in salinity does not exceed 5 No. 2 can be planted in mid-August.
Sixth, scientific feeding
Scientific feeding is to feed on the physiological needs of shrimp life and growth. Too much feeding will easily deteriorate the water quality and increase the bait cost. On the contrary, it is unable to meet the nutritional needs of shrimp and affect the normal growth of shrimp. Feeding should be rationalized, first of all to accurately estimate the number of pool shrimp. Several methods can be used to estimate: one is to use the cage method; the second is to use the rotary net sampling method; the third is to estimate the feeding and activity of the shrimp; and the fourth is to estimate the growth rate of the shrimp.
The bait-shrimp bait is mainly composed of artificially-combined bait. Later in the breeding period, it can be fed with live small shellfish such as gizzards and spiketails. Two days after the shrimp enters the pond, appropriate amount of bait can be put in to make up for the lack of basic bait. Feeding adopts the method of “few times, multiple days, many nights, even spreads, reasonable collocations, alternating use, first coarse and then fine†to improve the utilization of bait and the survival rate of shrimp, and promote the growth of shrimp. Normally, they are fed 4 times a day for 5:30, 9:30, 18:00, and 23:00, and each feeding amount accounts for 20%, 15%, 35%, and 30% of the daily feeding amount. After 1.5 hours of feeding, more than 70% of the shrimps were half-full or full-stomached. The shrimps did not have group-eating and feeding. This indicated that the amount of feeding was appropriate; if the foods were fed soon enough, the pool shrimps also ran in large numbers. When the residual stomach exceeds 30%, it indicates insufficient feeding. A small net can be set up at the poolside and in the middle of the pool to check food intake. The 8.5 mu shrimp pond can be set up with 4 to 6 nets.
Seventh, daily observation and management
Observe daily changes in feeding activities and living environment of shrimps 2 to 3 times. Observe the color and odor of the water body and the bottom of the pool, check the activity status and feeding conditions, check the safety of the dikes, check whether the gate leaks, and whether the nets are damaged or not. Does the disease occur? When abnormalities are found, appropriate measures for custody should be taken promptly. The survival number, body length, and body weight of the shrimp were measured every 15 days to observe whether the shrimp shell growth was normal. According to different growth stages of shrimp, timely replacement of drainage nets. Shrimp farms should purchase pH colorimeters, hydrometers, thermometers, oxygen meters and other water quality monitoring instruments to measure physical and chemical indicators such as water temperature, specific gravity, pH value, transparency, dissolved oxygen, etc., and make records so that water quality can be monitored and maintained. Pool water pH 8.0 ~ 8.5, water temperature 25 °C ~ 30 °C, salinity 8 ~ 15, dissolved oxygen 5 mg / liter or more, transparency 40 cm ~ 60 cm, water color light green or yellow-green, and maintain a good living environment for shrimp growth . Conditioned shrimp farms can use waterwheel aerators to increase oxygen, so that shrimp farming can achieve high yield and high efficiency.
Eight, disease prevention
Shrimp must implement the principle of "prevention, prevention, treatment, and prevention." Prevention of shrimp disease must be carried out throughout the entire process of aquaculture management. Thorough clearing of the pond before disinfection. During the cultivation period, regular sprinkling of 0.3ppm to 0.4ppm "strong chlorine" or 1ppm to 2ppm of bleach solution is required to disinfect and sterilize the pool water. Zeolite powder can also be periodically applied to purify water and sediment. The dosage per acre is 15kg to 20kg. Feed the bait once every two weeks and add it to the bait in accordance with vitamin C3‰-5‰, allicin-2‰, and cod liver oil 3‰-5‰. Feed the bait twice a day and feed it for 5 days to 7 days. Using these methods to prevent disease can get better results.
Nine, timely harvest
Pterodactyl prawn farming is a highly-invested industry with certain risks. Especially in the later period of aquaculture, the accumulation of residual baits at the bottom of the pond and the pollution of shrimp excrement are becoming more and more serious, and the risk of illness and lack of oxygen causing damage to pool shrimp will increase. Therefore, Penaeus monodon prawn is cultured for 80 days to 100 days, with an average of 40 to 60 tails per kilogram of shrimp, and more than 90% of the prawn should be harvested and sold. The common method of harvesting is to use a conical mesh bag to drain the shrimp or push the net and collect and combine the shrimp.
I. Ecological habits of Penaeus monodon
Penaeus monodon is inhabited by sand or mud sediments. It usually does not move during the day, and it has the strongest appetite in the evening and starts frequent foraging activities. Its adaptation to salinity ranges from 5 to 25, and the closer it grows to 10, the faster it grows. The suitable temperature range is 14°C to 34°C, and the optimum growth water temperature is 25°C to 30°C. When water temperature is lower than 18°C, feeding is stopped. If the water temperature is not lower than 12°C, it will not die. Strong omnivorous, the requirements for feed protein is 35% to 40%, shellfish, miscellaneous fish, shrimp, peanut bran, wheat bran, etc. can be fed. The maximum body length of P. monodon captured in the natural sea area is up to 33 cm and the body weight is between 500 and 600 grams. Shrimp cultured in ponds for 80 days to 100 days, body length up to 12 cm to 13 cm, body length growth of 0.1 cm to 0.15 cm per day, weighing about 25 grams. Each kg of shrimp up to 40 to 60, generally yields 100 kg to 200 kg per mu, can be raised in two years.
Second, shrimp pond construction
Shrimp tanks should be constructed in areas near the mid-high tide line where winds and waves are small, tides are smooth, beaches are flat, water is clear, and there are no sources of pollution. Sandy bottom is the best, and sand and mud bottom are the second. The general tidal range should be between 2 and 3 meters, and the duration of orgasm should not be less than 3 hours. The salinity of seawater should be 10 to 20, and the pH should be 7.8 to 8.5. Shrimp pond rectangular, length, width ratio of 2:1 to 4:1, along the inlet channel for "non-" arrangement. Shrimp pond area of ​​0.7 square kilometers to 1.0 square kilometers is good, the pool depth of 2.0 meters, water depth of 1.5 meters, the bottom of the pool should be flat, drain bottom is less than the bottom of the pool 30 cm to 40 cm, easy to drain pool water. Each shrimp pond should have independent entrance and exit gates. Three gates are provided on the gates of the inlet and outlet gates. The middle slot is used to install the gates, and the gates are installed inside and outside the slots. The slot width is 6 cm and the distance between the three slots is 0.6 to 1.0 meters for operation and management. Where conditions permit, water storage sedimentation tanks can be constructed according to 1/3 to 1/2 of the shrimp pond area. High-level pools should be constructed not far from the sea area, easy to pump water, clean and stable water quality, sandy bottom, and fresh water sources.
Third, clear pond disinfection
The dredging and drying ponds in shrimp ponds are the main link in healthy farming and must be thoroughly cleared. After the shrimps are harvested at the end of each year, the pool water is drained and the sun is sealed at the gates. It is sun dried until the bottom of the pond cracks, and then the residual bait, debris and silt are transported to the outside of the embankment, where they are ploughed and exposed. It is best to lay a layer of 10cm thick clean sand on the bottom of the pool to improve the shrimp pond bottom. In the new shrimp pond, the gate should be opened to allow the sea water to enter and rinse out, so that the pH value at the bottom of the pond can be stabilized at 7.5 or more to allow the shrimp to be released. About 20 days before stocking, a 60-mesh sluice net was installed, and clearing ponds were sterilized with drugs. First, 50 kg to 100 kg of lime were sprinkled per acre, then 20 cm of water was poured, and 0.2 ml of chrysanthemum was sprayed to dilute the water. After 3 days drain the water and rinse twice. Re-inlet water 30 cm and then soaked with tea bran 15 kilograms of water for 24 hours, even the slag Quanchiposa. Drugs should be applied evenly to any place in the pool for thorough disinfection.
Fourth, training basic food
Within 10 days to 20 days after the shrimps are stocked, the main foods are planktons, copepods, diatoms and other planktons, so the cultivation of basic food organisms is an important technical measure to improve the survival rate and growth rate of shrimp seedlings. After the tea bran is applied for 2 days to 3 days, 80 cm to 100 cm of water is poured, 2 kg of urea is applied per acre, and 0.2 kg of phosphate fertilizer is applied. After that, dressing is applied once every 3 days to 4 days, and the dosage is reduced by half so that the transparency of the water reaches 40 cm. ~ 60 cm. The pH value is between 8.0 and 8.5. The water color is yellow-green or green. The fertilizer can be released after 6 days to 10 days. If it is not possible to put the seedlings in time, the Feitang time reaches 20 days or more and the water quality becomes old. The six-shrimp shrimp (Ctenopharyngodon idellus) reproduces again, and it is necessary to re-drain, and the drug is used to kill the six-skrust shrimp, and then the influent fertilizer is applied to cultivate the basic bait. .
Fifth, put the shrimp
Shrimp seedlings require uniform individual size, robustness, strong vitality, good reversal ability, smooth surface without attachments, body length 1.2 cm or more, the first tentacles diverge in front of the V-shaped two small tentacles often close together, body section Sparse and long. P12-P18 black shell seedlings are preferred, and 4 to 6 spikes have been found on the forehead of the shrimp. The density of seedlings shall be determined according to the conditions of the shrimp ponds, the water environment and the management level. General shrimp pond water depth of 1.2 meters, 0.800 to 10,000 per acre put seedlings; water depth of 1.6 meters, 10,000 to 13,000 per acre Fangmiao. Conditional shrimp farms can increase the density of shrimp, and 20,000 to 40,000 mu can be planted. No. 1 can be planted from late March to early April. To select sunny weather, when the water temperature is stable above 25°C, plant the seedlings. When laying seedlings, the seedling bag is first immersed in the pool for 20 minutes so that the water temperature in the bag is close to the water temperature in the pool (the temperature difference does not exceed 3°C). The seedlings in the deeper places where the water is deeper are placed in the wind, and the shrimp and seedling pool water and the shrimp pond water The difference in salinity does not exceed 5 No. 2 can be planted in mid-August.
Sixth, scientific feeding
Scientific feeding is to feed on the physiological needs of shrimp life and growth. Too much feeding will easily deteriorate the water quality and increase the bait cost. On the contrary, it is unable to meet the nutritional needs of shrimp and affect the normal growth of shrimp. Feeding should be rationalized, first of all to accurately estimate the number of pool shrimp. Several methods can be used to estimate: one is to use the cage method; the second is to use the rotary net sampling method; the third is to estimate the feeding and activity of the shrimp; and the fourth is to estimate the growth rate of the shrimp.
The bait-shrimp bait is mainly composed of artificially-combined bait. Later in the breeding period, it can be fed with live small shellfish such as gizzards and spiketails. Two days after the shrimp enters the pond, appropriate amount of bait can be put in to make up for the lack of basic bait. Feeding adopts the method of “few times, multiple days, many nights, even spreads, reasonable collocations, alternating use, first coarse and then fine†to improve the utilization of bait and the survival rate of shrimp, and promote the growth of shrimp. Normally, they are fed 4 times a day for 5:30, 9:30, 18:00, and 23:00, and each feeding amount accounts for 20%, 15%, 35%, and 30% of the daily feeding amount. After 1.5 hours of feeding, more than 70% of the shrimps were half-full or full-stomached. The shrimps did not have group-eating and feeding. This indicated that the amount of feeding was appropriate; if the foods were fed soon enough, the pool shrimps also ran in large numbers. When the residual stomach exceeds 30%, it indicates insufficient feeding. A small net can be set up at the poolside and in the middle of the pool to check food intake. The 8.5 mu shrimp pond can be set up with 4 to 6 nets.
Seventh, daily observation and management
Observe daily changes in feeding activities and living environment of shrimps 2 to 3 times. Observe the color and odor of the water body and the bottom of the pool, check the activity status and feeding conditions, check the safety of the dikes, check whether the gate leaks, and whether the nets are damaged or not. Does the disease occur? When abnormalities are found, appropriate measures for custody should be taken promptly. The survival number, body length, and body weight of the shrimp were measured every 15 days to observe whether the shrimp shell growth was normal. According to different growth stages of shrimp, timely replacement of drainage nets. Shrimp farms should purchase pH colorimeters, hydrometers, thermometers, oxygen meters and other water quality monitoring instruments to measure physical and chemical indicators such as water temperature, specific gravity, pH value, transparency, dissolved oxygen, etc., and make records so that water quality can be monitored and maintained. Pool water pH 8.0 ~ 8.5, water temperature 25 °C ~ 30 °C, salinity 8 ~ 15, dissolved oxygen 5 mg / liter or more, transparency 40 cm ~ 60 cm, water color light green or yellow-green, and maintain a good living environment for shrimp growth . Conditioned shrimp farms can use waterwheel aerators to increase oxygen, so that shrimp farming can achieve high yield and high efficiency.
Eight, disease prevention
Shrimp must implement the principle of "prevention, prevention, treatment, and prevention." Prevention of shrimp disease must be carried out throughout the entire process of aquaculture management. Thorough clearing of the pond before disinfection. During the cultivation period, regular sprinkling of 0.3ppm to 0.4ppm "strong chlorine" or 1ppm to 2ppm of bleach solution is required to disinfect and sterilize the pool water. Zeolite powder can also be periodically applied to purify water and sediment. The dosage per acre is 15kg to 20kg. Feed the bait once every two weeks and add it to the bait in accordance with vitamin C3‰-5‰, allicin-2‰, and cod liver oil 3‰-5‰. Feed the bait twice a day and feed it for 5 days to 7 days. Using these methods to prevent disease can get better results.
Nine, timely harvest
Pterodactyl prawn farming is a highly-invested industry with certain risks. Especially in the later period of aquaculture, the accumulation of residual baits at the bottom of the pond and the pollution of shrimp excrement are becoming more and more serious, and the risk of illness and lack of oxygen causing damage to pool shrimp will increase. Therefore, Penaeus monodon prawn is cultured for 80 days to 100 days, with an average of 40 to 60 tails per kilogram of shrimp, and more than 90% of the prawn should be harvested and sold. The common method of harvesting is to use a conical mesh bag to drain the shrimp or push the net and collect and combine the shrimp.