A friend left a message in the comment area when I exchanged crayfish farming techniques with each other, and asked me to share the method of cultivating crayfish fry in intensive ponds. In order to meet his requirements, the following from my personal farming practice experience, to share the technical operation process in this regard.
Intensive crayfish culture and rice paddy farming of crayfish are similar in the method of rearing management. The use of intensive ponds to breed crayfish fry and rice paddies also have much in common. The difference is that the intensive crayfish pond and the ordinary rice shrimp field are somewhat different in the design of the excavation. This aspect is mainly reflected in the fact that the height of the enclosure of the intensive pond is slightly higher than that of the general rice and shrimp field. The vertical height of the intensive pond platform from the top of the enclosure should be more than 1.2 meters. To ensure that when breeding in high temperature periods, the water level in the breeding pond can be stabilized at about 80 cm.
The use of intensive ponds to cultivate crayfish fry, in June and July should not increase the water level of the shrimp ponds too high, normal breeding, as long as the water surface and the top of the enclosure is 30-40 cm away. This ensures that the broodstock that has completed mating and ovulation has plenty of room to hatch the inseminated eggs.
In order to cultivate early crayfish seedlings in non-rice shrimp fields, it is necessary to reserve a large number of shrimp with an individual size of about 25 grams in June when breeding crayfish in the first season. This requires that when we catch and sell the first season of crayfish, we must observe the amount of finished crayfish caught every day in the later stages of the cage.
If a four-meter-long cage is placed at a distance of about ten meters along the enclosure, after an overnight fishing, the number of adult shrimp caught in each cage is less than 20, that is to say, about one pound or so, the fishing will be suspended. If there are too few shrimp, you can also buy another part of the stock. Otherwise, the number of seed shrimp reserved is not large, and it is difficult to breed more shrimp fry.
In order to enable the crayfish fry cultivated in the second season of intensive ponds to be able to grow into large sizes that year, we must strictly control the number of stocking shrimp fry when stocking shrimp fry. Considering that there are about hundreds of shrimp per mu in the original pond, and the crayfish are in the high temperature period when the second season is farmed, it is best to control the number of shrimp fry on the surface of one mu of water at about 3,000.
The process of mating and hatching fertilized eggs takes about two and a half months for the shrimp reserved in intensive ponds, which means that in mid-to-late September, many female shrimp have hatched inseminated eggs into seed shrimp. In order to more accurately grasp the time of flooding the hole, we can check the process of female shrimp hatching fertilized eggs by digging a hole.
As long as it is determined that most of the female shrimp have completed the hatching of the inseminated eggs, or the inseminated eggs have entered the end of hatching, the water level of the intensive pond can be raised in time to force the broodstock out of the hole. After two to three days in the upper water, the water level is restored to its original position and continued to be reared and managed.
During this period, some of the breeding management problems to be paid attention to are the use of intensive ponds to cultivate shrimp fry, it is best to plant a certain area of water peanuts in the ring ditch, the end of the first season of intensive farming of crayfish, if the pond can not continue to use until the end of the second season of breeding, it is necessary to reduce the water level of the shrimp pond to the upper mouth of the ring ditch for several centimeters, and then rotate tillage on the shrimp pond platform, when rotating tillage, leave a width of one meter every interval of about five meters, so that after re-entering the water, there is no place for rotary tillage, and the algae will sprout new roots and continue to grow again. After about half a month, the shrimp fry can be stocked again to continue farming. Doing so can greatly save time from replanting aquatic weeds to seedling release.
In addition, in order to reduce the density of crayfish culture in intensive ponds, some adult shrimp that reach market size should be caught and sold in time in September. This effectively avoids the occurrence of a large number of adult shrimp hazard hatching crayfish seedlings.
At the same time, in order to take into account the rapid growth of the juvenile shrimp hatched in the intensive pond, it is necessary to pay attention to the fertilization of the shrimp pond from the beginning of the flooded cave. After a large number of seedlings appear in the shrimp pond, every two days, some soy milk or other powdery fermented high-quality feed is sprinkled to feed the seedlings. With the continuous growth of seedlings, it is also necessary to timely feed commercial special compounds with a particle diameter of 0.5-1.0. When continuing to harvest finished shrimp in the future, the aperture of the ground cage used should also be moderate, so as to prevent some shrimp fry from being caught and stocked multiple times, causing harm to them.
The seed shrimp hatched in September can generally grow into a pound of about 120-150 fish years ago, reaching the standard of stocking in the pond.
After the shrimp fry are transferred to the pond for stocking or sale, the intensive pond of the nursery needs to be thoroughly cleared for further use in the next culture cycle.
Welcome to pay attention to "Huai'an Lao Chen", so that your farming of crayfish will be smoother from now on!
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