River crab cultivation technology

Crab breeding is an important part of river crab production, and the cultivation of young crab crabs is conducive to high yield and efficiency. If the crab bigeye larvae are directly put into the crab pool, not only the early spring temperature is low, the crab seedlings can not survive, but also due to the lack of food to kill each other, resulting in survival rate, in the 3-5 months need to build crab breeding seedlings Plastic greenhouses, according to the biological characteristics of juvenile crabs, provide the environmental conditions required for their growth and shelling, and sufficient food to develop five young crabs of the same size, suitable size, and high survival rate.

First, build a pool. Crab breeding ponds are based on the amount of crabs, generally 0.5-1 mu. The pool depth is 0.8-1 meters, the water depth is 0.4-0.8 meters, and the slope ratio is about 1:1.5. The water is abundant and the water quality is good. The bottom of the pool is hard and the pool is solid and does not leak water. The bottom plane of the tank is inclined towards the outlet. The pond is rectangular and arranged in the east-west direction with an aspect ratio of 5:3.

Second, Qingchi disinfection. Qingchi can kill enemy creatures in the pool. Before restocking crabs, the silt in the nursery pond should be removed and holes and cracks should be filled. Newly built crab ponds or crab ponds that have been converted from fish ponds should be disinfected with drug clearing ponds prior to stocking, and bleaching powders should be used for clearing ponds. The method of using the bleaching pond: firstly calculate the volume of the pool water, and use 20 grams of bleaching powder (20ppm) per cubic meter of water. After the bleaching powder required in the nursery pond is dissolved in water, it will immediately splash in the whole pond. Normally, the crab will be released 5 days after the clearing pond. seedling. Pay attention to the saline-alkali soil pool is alkaline, PH value is relatively high, can not use alkaline lime as clear pond drugs.

Third, the arrival of crab seedlings. To achieve “human seedlings, car seedlings, ponds, and other seedlings”, the crab seedlings should be put into the pool water for 2 minutes after being transported to Tangkou, and then lifted, so that it should be reciprocated 2-3 times to make crabs. The seedlings are adapted to the pond water temperature and water quality, and then put into the cage for raising. After the crab seedlings are placed in cages, the live crabs will automatically swim out and the cages will be removed. After the crabs were normal, they were given medications for leeches.

Fourth, stocking density. Generally, 80-150 (5-10 kg) crabs are stocked on each acre. The specifications are large, the quality is good, and the density can be thinned. On the contrary, it is denser.

Fifth, planting plants. To plant water peanuts, duckweed, and bitter grass, first rinse the water peanuts, duckweed, and bitter grass with river water, wash off most of the attached shrimp seeds and fish eggs, and disinfect them with 20 ppm potassium permanganate solution. Bacteria, which can purify water quality, can also use water peanuts, duckweed, and bitter grass as habitats and young crab feed.