Detailed Explanation of the Five Key Technical Measures for Crab Farming

Feed with Caution

Feeding should be based mainly on high-quality pellet feed, frozen fresh small fish and soybeans, and powdery feed should be avoided as much as possible to reduce pollution of the water body. The amount of feed should be appropriately increased or decreased according to the season, weather and the growth and activity of the river crab. During the molting period of the river crab, nutritional additives should be added to the feed to ensure normal molting and growth of the river crab.

Dry the Pond Early

Generally, the pond is dried in January each year. After drying, the pond edges are cleared of silt and the banks are repaired. The pond should not be dried for too long; generally 10-15 days is appropriate, and it is sufficient for the pond bottom to be slightly firm. This reduces damage to the aquatic plants and benthic organisms in the pond and maintains the pond's original ecology.

Plant Grass Densely

In the early stage, the pond should be planted with many kinds of grass and sufficient grass; in the middle stage, the grass should be managed well: First, if the water color is too dense, it affects the photosynthesis of the aquatic plants, so the water should be adjusted in time. Second, if the water quality is turbid and the aquatic plants are attached with pollutants, water-purifying biological agents should be used promptly to remove them. Third, if the aquatic plants wither and lack activity, fertilizer should be applied in time. In the later stage, the coverage of aquatic plants on the pond surface should be controlled at about 60%, and the old grass heads of the aquatic plants exposed above the water should be cut off so that the river crab can grow healthily in a good ecological environment.

Add Many Snails

Use multiple stockings; prevent a one-time large input from causing the water quality in the early stage to be lean and clear, leading to a large proliferation of moss. Before Qingming, put in one batch of snails at 300 jin/mu, and by the end of June gradually supplement the stocking, with the snail amount at 500 jin/mu, so as to regulate the pond water quality well, which is also conducive to the natural reproduction of snails and ensures that the pond has sufficient natural live bait in the middle and late stages of farming.

Water Regulation

August is a high-temperature period and a stage of seasonal transition. In order to appropriately lower the water temperature and minimize temperature differences, the pond should maintain its highest water level, with frequent adding and changing of water: add new water once every 2-3 days, and change the water once every 7-10 days. Water should be added in the early morning or morning, not in the evening. Use a microbial preparation once every 7-10 days on a regular basis to regulate water quality and keep the water fresh at all times, so that the river crab suffers fewer deaths during the high-temperature season and the survival rate is ensured.