Detailed key points for juvenile crab cultivation, crab farming techniques shared

1. Create a good ecological environment. First, the nursery pond area should be about 5-10 mu, which is conducive to uniform feeding and water quality control and other management tasks, and also facilitates one-time pond clearing, harvesting and sales; second, do a good job of pond clearing and escape prevention to prevent snakes, frogs, wild trash fish and other predators from entering the pond; third, maintain moderate water fertility in the nursery pond. Biological agents can be used to fertilize the water, which can not only provide abundant natural food for the megalopa, but also effectively prevent the mass reproduction of moss and maintain stable water quality in the middle and late stages; fourth, maintain an appropriate density of aquatic plants. For juvenile crab cultivation, water peanut is preferable, and the optimal water peanut distribution density should be maintained at each stage of the nursery pond according to different seasons and different developmental stages of juvenile crabs; fifth, adjust the water level in a timely manner, maintain good water quality, and at the same time promote molting of juvenile crabs.

2. Stock high-quality megalopa in the pond at the right time. Stocking at the right time means that the quality of the megalopa meets the requirements for freshwater cultivation, and the physical, chemical and biological indicators of the nursery pond water meet the optimal requirements for juvenile crab cultivation. First, the quality of the megalopa is good; second, the water fertility of the nursery pond is suitable and rich in natural live food favored by megalopa; third, maintain clear and good weather for the next 3 days; fourth, before stocking the megalopa, first let them adapt by moistening with water, with the temperature difference controlled within 3°C.

3. Scientifically feed high-quality compound feed. First, do not feed feed ingredients with extremely low utilization rates and poor palatability such as fish mince, egg yolk, soybean milk and fish slurry. These ingredients are not only uneven in size, leading to uneven feeding, which is not conducive to synchronous metamorphosis of megalopa and balanced development of young crabs, but these feeds also spoil easily and easily lead to deterioration of water quality, which is not conducive to disease prevention. In production, megalopa should be stocked in fertilized water and mainly prey on natural food; second, determine key and non-key feeding areas according to the distribution of young crabs in the pond. The key areas should be fed more, which can effectively reduce the degree of uneven feeding by young crabs, and following the principle of “multiple feedings and more feeding” can reduce the size differences among young crabs; third, after September, feeding should be carried out normally. If there are still many relatively small young crabs at this time, feeding measures focusing on high-quality small pellet feed should be taken in a timely manner to promote sufficient feeding by small young crabs. This is of great significance for controlling disease outbreaks in juvenile crabs the following spring and promoting early molting.

4. Strengthen disease prevention and control. The relatively common diseases during juvenile crab cultivation are young crab shore-climbing syndrome, rotten limb and shell rot disease, ciliate disease, and predators such as rats, snakes, frogs and fish. Before stocking megalopa, fertilize the water with biological fertilization methods, use microecological preparations throughout the pond in sufficient amounts to regulate water quality, and after each molting of young crabs, promptly use jiaqiaojing once to kill ciliates, then disinfect the whole pond, which has a significant effect on young crab shore-climbing. Regularly add microecological preparations to the feed, which is beneficial for promoting the growth of young crabs and improving disease resistance, and regularly improve the water with microorganisms. Prevent water quality deterioration, algal death and other sudden water quality changes, effectively maintain water quality, and pay attention to preventing hypoxia. Do a good job of regularly disinfecting the pond water, and take timely countermeasures when disease is found.