Crab Farming Techniques: Key Points and Methods Explained
First, cultivate juvenile crabs. 15—20 days before releasing the crab seedlings, splash 75 kg of quicklime per mu for disinfection, and set up the necessary anti-escape facilities. Choose a pond with sufficient water source, convenient water inlet and drainage, good water quality free of pollution, and good aeration. Then transplant aquatic plants, set up the necessary anti-escape facilities, and feed them the way fish are fed in pond culture, following the “four observations and four fixings”.
1. Pond Conditions
The pond water depth should be kept at around 0.6—1.5 m year-round, with varying depths in different places and a minimum depth of 10 cm. Several earthen mounds slightly above the water surface, known as crab islands, can be built in the pond, and aquatic plants can be transplanted onto the islands. The pond should not be too steep, with a slope ratio generally below 1:1.5, and artificial burrows can also be built. Generally, half a month before releasing the seedlings, use quicklime to clear and disinfect the pond at 75 kg per mu.
2. Transplanting Aquatic Plants
The main types of aquatic plants include duckweed, Azolla, water hyacinth, water lettuce, Hydrilla verticillata, hornwort, Vallisneria, and alligator weed. Pay attention to disinfection and pest prevention when transplanting. Anti-escape facilities are mostly made of plastic film, though cement boards are also used, depending on individual circumstances.
3. Seedling Stocking Density
Seedlings purchased from other places cannot be placed directly into the pond. They should first be soaked in water for 2—3 minutes, taken out and left for 10 minutes, and this repeated 2—3 times. After the young crabs gradually absorb enough water and adapt to the water temperature, they can be put into the pond, which can improve the survival rate. The density can be controlled within 1500 crabs per mu, with juvenile crabs sized 120—150 per kg. If conditions are poor or shrimp farming is the main focus, the stocking amount can be appropriately reduced.
4. Feeding Management
Crabs are fed the way fish are fed in pond culture, following the “four observations and four fixings”, namely observing the season, observing the weather, observing the water quality, and observing the crabs' activity, and fixing the time, fixing the location, fixing the quality, and fixing the quantity.