The more lazy crabs, the smaller the output, the more industrious people can prevent lazy crabs.

The so-called lazy crab refers to the river crab that has been living in caves, sand and stone crevices far from the water for a long time and cannot molt and grow up without coming out to move or forage. Lazy crabs are waste products and have no economic value. the more lazy crabs are, the lower the yield is, and the less likely it is to be successful in river crab farming. However, as long as farmers can manage in accordance with scientific management methods, so as to "people diligently prevent crab laziness", there is still a great possibility of successful river crab culture.

River crab culture

1. Make a good temporary breeding pass: either lack of breeding experience or save trouble. Some farmers directly put bigeye larvae into adult crab culture ponds. In the process of turning bigeye larvae into Ⅰ, Ⅱ and Ⅲ crabs, due to their weak swimming ability and predation ability, they have to gather on the shore for a long time, especially in case of wind and waves. The growth of river crab is accomplished by periodic molting. River crab can not synthesize ecdysin and must be ingested from the outside world. If the intake of ecdysone is insufficient, it can not molt normally. For reasons such as poor management, some young crabs that cannot eat bait have no choice but to dig holes on the shore and ingest humus in the nearby soil, but they are unable to molt their skin. After a long time, they become lazy crabs. Crab seedlings must be temporarily raised before being put into the culture pond. There are many temporary cultivation methods. It is better to raise crabs temporarily in cages, and water bodies such as soil ponds and cement ponds can also be selected. If there is no temporary culture pond, fine mesh can be used to intercept a small body of water in the corner of the culture pond for temporary cultivation. During the temporary maintenance period, the water quality should be fresh, the dissolved oxygen should be rich, and some attachments should be arranged manually. The bait is mainly animal bait, supplemented by plant bait. Bait should be uniform so that all the young crabs can get enough bait. When bigeye larvae become Ⅲ stage crabs, they are cultured in adult crab ponds.

2. The conditions of the pond should be good: if the bottom material of the crab pond is uneven, especially the large cracks in the bottom soil or sand near the water surface, the river crabs are easy to use the cracks to hide and dig holes. The northern region is windy in spring, and the waves, evaporation and leakage caused by the wind will erode into a 10-20cm section with almost no slope ratio on the shore, and the river crabs living in caves in this section are easy to become lazy crabs. Therefore, the water surface slope of the pond is better than that of the pond with a surface slope of more than 1 / 2 / 5 / 1 / 3, the bottom material should be flat and seamless, and the water retention performance of the pond is better.

3. Feeding should be uniform and adequate: the early feeding of young crabs into the pond is very important, and baiting should follow the four principles, especially in these two peak feeding periods: first, in April-May, shortly after entering the pond; second, before molting in the later stage of culture, the feeding amount of river crabs is relatively large, and full bait should be given.

4. Transplant aquatic plants and attachments: for ponds without aquatic plants or with few aquatic plants, some aquatic plants or aquatic plants can be planted artificially, and the area of aquatic plants accounts for about 1 inch of the water area of the pond. It can also manually arrange some nets or dead tree branches as attachments, which can not only create a good habitat environment for river crabs, but also provide a hidden place for river crabs to molt, and has a variety of functions such as providing bait, purifying water quality, shading and cooling, and so on.

5. Keep the water level stable: River crabs often dig holes on the pool slope between high water level and low water level. after being temporarily raised into the crab pond, the crab seedlings should be raised to the required position at one time, and the water level should be kept relatively stable in the future. If you need to change or add water in the future breeding process, it must be added to the original water level, which is very important.

6. Maintain good water quality: River crabs like to live in water bodies with clean water quality, rich dissolved oxygen and lush water plants, so, in addition to not having to be polluted and replace the deteriorating pond water in time, crab pond water should be injected regularly until adult crabs come out of the pond. always keep the pond water fresh, alive, tender and cool, and disinfect the water regularly, and if necessary, be equipped with an aerator.

7. After finding lazy crabs, we should take remedial measures, raise them carefully, and add molting bait. When necessary, you can concentrate on intensive feeding of lazy crabs and put them into the water body with climbing objects.