Early breeding of crab species to develop commodity crab technology
2020-06-04 11:09:23
The so-called early breeding of crab species. It is the juvenile crab species cultivated from the big eye larvae before April. The size of this crab species is generally between 200-2000 kg/kg. The stock of most crabs in the year can be grown into commercial crabs. Its technical points are not exactly the same as traditional crab-rearing techniques. Its main feature is to adopt advanced feeding and management techniques, and to appropriately place early-breaking, late-breaking, and night-time markets. In the specific operation, the following should be noted:
1. Selecting good crab species should be selected from March-April, and gourd crabs, rivers, and other river crabs should be stocked with crabs. The requirements for the specifications of crab species vary depending on the environmental conditions such as the size of the water surface. Large lake crabs such as lakes, rivers and reservoirs, and reservoirs may have larger specifications, and ponds and other small water surfaces may be smaller. In general, the size of crab species should be below 2,000/kg, and the bigger the better, the crab species should be pure and high quality.
2. The choice of stocking water area should be selected from water sources without pollution, the dissolved oxygen in water is above 5 mg/L, the source of feed is abundant, the amount of water grass is more, there is less enemy predators, and the access area is powered by water. Large water surface should be easy to escape and catch. The pond should be convenient for drainage and irrigation. The pond area should be between 2 and 20 acres. Depth of water: The water depth in shallow water is 20-40 centimeters, Bu accounts for about 1/3 of the total water surface, and the deep water depth is 1.2--1.5 meters, accounting for about 2/3 of the total water surface.
3. Density, time, and method of stocking The stocking density varies with individual crab size, water conditions, and feeding and management levels. In general, the pond stocking density is 500-600/mu; Lake reservoirs and large river channels are 200---300/mu, good condition can raise stocking density appropriately. The time of stocking usually begins in April, that is, when the water temperature reaches 15°C or above, it is always available until August, but it is better to place it early. The method of stocking is to place the crabs in the box or on the wooden board; then put the boxes and plates on the leeward sunny side and the watery surface to allow the crabs to climb into the water.
4. Strengthen feeding and management The so-called “strengthening feeding and management†is mainly a high-nutrition, high-level feeding management and other measures. It is a new technique that promotes the rapid growth of crabs, enlarges individuals, and improves the city’s market. The technical requirements are as follows: 1 More animal feeds such as small trash fish, snail meat, and animal waste shall be fed, and vegetable seeds such as soybeans, bean cakes, wheat, corn, carrots, hawthorn, and green vegetables should be properly matched. Daily fixed-point fixed-time quantitative feeding 3 - 4 times, but also to increase the shrimp and clam shells promote clam shell. For the rich surface of the source of feed can be fed less, but it must not follow the people to put "Tian Yang" approach. 2 Strengthen water quality management. The water is often kept fresh and the dissolved oxygen in the water remains above 5 mg/l. 3 strengthen daily management. Conduct frequent inspections and do a good job of preventing fleeing, preventing storms, preventing stealing, preventing pests and predators.
5. Properly postponed fishing time should be “Southern and early Northâ€. In the Yangtze River basin and north of China, catches should be taken before and after the frost fall, and the south can be later. The general purpose is to keep the crab as long as possible. Time, higher maturity. At this time, most of the crabs caught can reach 100 grams or more. The listing is more popular with customers. For a small number of small crabs that do not meet the market specifications, they can be used in the breeding waters for the next year to raise the size of commodity crabs or move to other waters for continued cultivation. When catching late, pay attention to anti-escape and antifreeze work.
1. Selecting good crab species should be selected from March-April, and gourd crabs, rivers, and other river crabs should be stocked with crabs. The requirements for the specifications of crab species vary depending on the environmental conditions such as the size of the water surface. Large lake crabs such as lakes, rivers and reservoirs, and reservoirs may have larger specifications, and ponds and other small water surfaces may be smaller. In general, the size of crab species should be below 2,000/kg, and the bigger the better, the crab species should be pure and high quality.
2. The choice of stocking water area should be selected from water sources without pollution, the dissolved oxygen in water is above 5 mg/L, the source of feed is abundant, the amount of water grass is more, there is less enemy predators, and the access area is powered by water. Large water surface should be easy to escape and catch. The pond should be convenient for drainage and irrigation. The pond area should be between 2 and 20 acres. Depth of water: The water depth in shallow water is 20-40 centimeters, Bu accounts for about 1/3 of the total water surface, and the deep water depth is 1.2--1.5 meters, accounting for about 2/3 of the total water surface.
3. Density, time, and method of stocking The stocking density varies with individual crab size, water conditions, and feeding and management levels. In general, the pond stocking density is 500-600/mu; Lake reservoirs and large river channels are 200---300/mu, good condition can raise stocking density appropriately. The time of stocking usually begins in April, that is, when the water temperature reaches 15°C or above, it is always available until August, but it is better to place it early. The method of stocking is to place the crabs in the box or on the wooden board; then put the boxes and plates on the leeward sunny side and the watery surface to allow the crabs to climb into the water.
4. Strengthen feeding and management The so-called “strengthening feeding and management†is mainly a high-nutrition, high-level feeding management and other measures. It is a new technique that promotes the rapid growth of crabs, enlarges individuals, and improves the city’s market. The technical requirements are as follows: 1 More animal feeds such as small trash fish, snail meat, and animal waste shall be fed, and vegetable seeds such as soybeans, bean cakes, wheat, corn, carrots, hawthorn, and green vegetables should be properly matched. Daily fixed-point fixed-time quantitative feeding 3 - 4 times, but also to increase the shrimp and clam shells promote clam shell. For the rich surface of the source of feed can be fed less, but it must not follow the people to put "Tian Yang" approach. 2 Strengthen water quality management. The water is often kept fresh and the dissolved oxygen in the water remains above 5 mg/l. 3 strengthen daily management. Conduct frequent inspections and do a good job of preventing fleeing, preventing storms, preventing stealing, preventing pests and predators.
5. Properly postponed fishing time should be “Southern and early Northâ€. In the Yangtze River basin and north of China, catches should be taken before and after the frost fall, and the south can be later. The general purpose is to keep the crab as long as possible. Time, higher maturity. At this time, most of the crabs caught can reach 100 grams or more. The listing is more popular with customers. For a small number of small crabs that do not meet the market specifications, they can be used in the breeding waters for the next year to raise the size of commodity crabs or move to other waters for continued cultivation. When catching late, pay attention to anti-escape and antifreeze work.
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