Artificial Stocking and Farming Techniques for Chinese Mitten Crabs in River Channels

Generally, river crabs are farmed in ponds. This requires escape-prevention facilities and the feeding of artificial bait, resulting in relatively high costs. Artificial stocking and farming of river crabs using river channel resources is based on the river crab's unique behavioral patterns: juvenile crabs swim upstream against the current, adult crabs crawl close to the bottom moving downstream with the flow, and they generally do not float in the water while moving. At the same time, combined with the natural bait resources in river channels, there is no need to feed artificial bait, making it a low-investment, quick-return profitable project. The key technical points are as follows:

1. River channel selection: Choose a river channel far from cities, with no factories nearby and no discharge of the three wastes (waste water, waste gas, and industrial residue). The river surface should be wide, the water flow gentle, the water clear to the bottom, and the water should be rich in aquatic animals and aquatic plants.

2. Ground cage placement: Based on the growth patterns of river crabs, in the early stage use several ground cages 60 cm high and 80 cm wide, tied shut at both ends to prevent juvenile crabs from escaping; in the mid-stage rainy season, set up blocking nets at gaps in the river channel to prevent escape; in the late stage, set up ground cage nets downstream to capture adult crabs.

3. Stocking of crab seed: ① Crab seed selection: The crab seed used for river channel farming must be selected from purebred juvenile crabs (button crabs) with intact limbs and normal body color. ② Stocking time: Late April to early May. ③ Stocking density: Stock crab seed of 600-1000 individuals/kg at a density of 600-800 individuals per mu.

4. Daily management: Carry out daily patrols of the river channel, check the ground cage nets for damage, remove debris from the nets, and especially during the rainy season, pay attention to preventing river crabs from escaping at gaps in the diversion channel.

5. Recapture: The growth and living patterns of river crabs are as follows: in the late stage of farming, when the river crabs reach market size, they begin to move downstream in groups, and at this time, in the lower reaches of the river channel, multiple ground cage nets can be used to capture them.