How to breed river crabs

1, pond preparation

The aquaculture pond should be selected in a place with abundant aquatic plants, clean and clear water quality and abundant sunshine, and the area of the pond should be determined according to its own aquaculture quantity. Generally, it is about 3-8 mu, and the water should not be too deep. There is a good irrigation and drainage system around1.2m. The pond should be made of hard clay and the thick silt at the bottom should be removed. Anti-escape equipment should be set around the pond. In order to reduce the occurrence of diseases in the breeding process, the pond should be cleaned and disinfected when stocking crab seedlings. Before stocking 15 days, the whole pond is sprayed with quicklime, and the dosage per mu is about 75 kg. Quicklime can not only kill bacteria in the pond, but also effectively increase calcium ions in the water and improve the bottom of the pond.

2, seed selection and seedling release

When choosing crab species, you should choose excellent and pure varieties, not mixed crabs, crabs with injuries and crabs with broken limbs. Crab species should grow well, develop well, have complete appendages, have no trauma, and have little difference in size. The purpose is to ensure the quality and late survival rate of river crabs. When stocking crab species, crab seedlings should be kept for a while. In order to allow crab seedlings to have an excessively long adaptation period, a temporary culture area was set up in the pond, accounting for about 1/5 of the whole pond. Pay attention to the stocking density, which should be moderate to ensure the normal growth and development of river crabs, and the density should be controlled at about 2000 per mu. Stocking time is generally around early spring.

3. Feed feeding

When raising river crabs, we must feed them reasonably, because it is impossible to meet the growth and development of river crabs and achieve the goal of high yield by eating natural bait alone. After stocking crab species, when the water temperature in the pond reaches 1 1 degree or above, it needs to be artificially fed. Concentrated feed should be given priority to in the early stage of feed, coarse feed should be given priority to in the middle stage, and meat feed should be given priority to in the later stage. Feed a small amount of paste bait in spring and plant feed in summer. After August, it is necessary to increase the feeding amount of animal meat. The main purpose is to promote the gonad development of Eriocheir sinensis, increase its weight and make its meat more delicious.

4. Water quality management

Water quality has a very important influence on the growth and survival rate of river crabs, so water quality management must be done well. When stocking crab species, it is necessary to ensure that there is a certain fecundity in the water, and the fecundity cannot be reduced, so water should be added at least once a week when breeding. And the water level will deepen with the increase of temperature. The water level should reach at least 1.5m in July, and the frequency of water change should be increased or decreased when the temperature rises. Change the water at least once every half a month from May to June in summer, and at least once a week from July to August. After the temperature drops, the frequency of changing water can be gradually reduced. Every time you change the water, you don't need to change the whole pool water, just change it by about 30%, and you need to sprinkle quicklime regularly. It is about once every 15 days, and the effect is the same as mentioned above.