Improving the survival rate of scallops during nursery
2018-04-26 14:00:35
Scallops mainly include scallops, scallops, and bay scallops. Now that the nursery period is imminent, when scallop seedlings are raised, the survival rate of seedlings should be improved. The following points should be made:
1. Select the appropriate pond for seedling conservation. The ponds are preferably east-west with a rectangular structure, sandy or hard bottom, with a water depth of 1.5 meters or more and a salinity of 35 feet or less, leading to no contaminated water from the outer sea. Before the pond enters the water, the bottom of the pool should be completely removed and fully exposed. It is forbidden to stock large-sized benthic fish or other species that require large amounts of feed in Baomiaotang to prevent pollution of pool water.
2. Do a good job of water quality control. The juveniles enter the water for 10 to 15 days before entering the pool for 60 to 80 cm and fertilize. 3.5 grams of nitrogen fertilizer is applied per cubic meter of water body, and the amount of phosphate fertilizer is generally about 10 times that of nitrogen fertilizer, and the bait density is controlled at 5 to 200,000/ml. Gradually increase the pool water to the highest water level 45 days before the seedlings, with a transparency of 70-80 cm. If the transparency is too high and the temperature is high before and after noon, inorganic fertilizers shall be topped up in a timely manner with a small amount of work. If the transparency is too low and the bait density is too high, the shellfish should be properly increased for several days before entering the pool. The amount of water makes the water clear but not thin, fat and not old. Before releasing the seedlings, it is necessary to strictly monitor the physical and chemical indicators of the water quality of the seedling nursery pool to ensure that all indicators are within the prescribed limits. After the seedlings, the daily water exchange volume should be more than 20 times that of the water body. If the water color mutation occurs as a sign of water quality aging and death of the shellfish seedlings, the water should be completely changed or the seedlings should be changed in time.
3. Select high quality juvenile vaccine. When leaving the warehouse, carefully select the juvenile seedlings with uniform specifications, firm attachment, appropriate density, and less than 15 days of attachment time. The water quality of the nursery is basically the same as that of the nursery pond. The general pond water temperature is stable at 13°C and can be kept in ponds for seedlings. Single-cell algae bait varieties in nursery should be reasonable, and the supply is sufficient to ensure uniform and healthy juveniles.
4. Appropriately increase the juvenile delivery specifications. The general juveniles' delivery specifications are 500 μm, and the specifications are increased to 700-800 μm, which can greatly increase the seedling maintenance rate.
5. Shipment seedlings operating procedures. The bagging personnel should perform pre-post technical training. The operation should be skillful. The bagging time should be shortened as much as possible. The attachment base should be lifted to the bag mouth with a polyethylene wire to avoid the multilayer rolling and backlog friction and cause injury. It is suitable to transport seedlings in the early morning or evening. During transportation, it is necessary to pay attention to sealing, moisturizing and cooling, and try to shorten the transportation time.
6 reasonably determine the seedling density. In general, the water surface can use no more than 100 million juvenile 500-micron juveniles and no more than 30,000 seedlings per bag. With the increase of the size of juvenile shipments, the number of seedlings was appropriately reduced.
1. Select the appropriate pond for seedling conservation. The ponds are preferably east-west with a rectangular structure, sandy or hard bottom, with a water depth of 1.5 meters or more and a salinity of 35 feet or less, leading to no contaminated water from the outer sea. Before the pond enters the water, the bottom of the pool should be completely removed and fully exposed. It is forbidden to stock large-sized benthic fish or other species that require large amounts of feed in Baomiaotang to prevent pollution of pool water.
2. Do a good job of water quality control. The juveniles enter the water for 10 to 15 days before entering the pool for 60 to 80 cm and fertilize. 3.5 grams of nitrogen fertilizer is applied per cubic meter of water body, and the amount of phosphate fertilizer is generally about 10 times that of nitrogen fertilizer, and the bait density is controlled at 5 to 200,000/ml. Gradually increase the pool water to the highest water level 45 days before the seedlings, with a transparency of 70-80 cm. If the transparency is too high and the temperature is high before and after noon, inorganic fertilizers shall be topped up in a timely manner with a small amount of work. If the transparency is too low and the bait density is too high, the shellfish should be properly increased for several days before entering the pool. The amount of water makes the water clear but not thin, fat and not old. Before releasing the seedlings, it is necessary to strictly monitor the physical and chemical indicators of the water quality of the seedling nursery pool to ensure that all indicators are within the prescribed limits. After the seedlings, the daily water exchange volume should be more than 20 times that of the water body. If the water color mutation occurs as a sign of water quality aging and death of the shellfish seedlings, the water should be completely changed or the seedlings should be changed in time.
3. Select high quality juvenile vaccine. When leaving the warehouse, carefully select the juvenile seedlings with uniform specifications, firm attachment, appropriate density, and less than 15 days of attachment time. The water quality of the nursery is basically the same as that of the nursery pond. The general pond water temperature is stable at 13°C and can be kept in ponds for seedlings. Single-cell algae bait varieties in nursery should be reasonable, and the supply is sufficient to ensure uniform and healthy juveniles.
4. Appropriately increase the juvenile delivery specifications. The general juveniles' delivery specifications are 500 μm, and the specifications are increased to 700-800 μm, which can greatly increase the seedling maintenance rate.
5. Shipment seedlings operating procedures. The bagging personnel should perform pre-post technical training. The operation should be skillful. The bagging time should be shortened as much as possible. The attachment base should be lifted to the bag mouth with a polyethylene wire to avoid the multilayer rolling and backlog friction and cause injury. It is suitable to transport seedlings in the early morning or evening. During transportation, it is necessary to pay attention to sealing, moisturizing and cooling, and try to shorten the transportation time.
6 reasonably determine the seedling density. In general, the water surface can use no more than 100 million juvenile 500-micron juveniles and no more than 30,000 seedlings per bag. With the increase of the size of juvenile shipments, the number of seedlings was appropriately reduced.