Three precautions for culturing river crabs in autumn: water temperature, adult crabs and digestion

First, pay attention to prevent drastic changes in water temperature

Crab ponds should maintain a certain water level in autumn to prevent drastic changes in water temperature. In addition, the temperature difference should not exceed 3 ℃ when adding new water to prevent crabs from catching cold and dying.

Pay attention to the timely sale of sexually mature crabs

Before and after Frosts Descent every year, the gonads of a group of two-year-old river crabs mature, showing dark green back shell, thick and long villi of male crabs, strong chelate feet and strong footsteps, and the navel of female crabs becomes oval, surrounded by small black hairs. At this time, the osmotic pressure of the river crab increased and often died because it could not adapt to the freshwater environment with low osmotic pressure. Therefore, these crabs should be caught and sold on the market in time.

Third, pay attention to prevent indigestion of river crabs

The changes of water temperature and climate in autumn can easily affect the appetite of river crabs and cause indigestion and death. At this time, the following prevention and control measures should be taken in time:

(1) improve water quality and regularly sprinkle the whole pool with quicklime water for disinfection.

(2) feed more animal feed with high protein and plant feed, and regularly add antibiotics and auxin to the food;

(3) the feeding was carried out strictly according to the requirements of "Siding", and the amount of feeding decreased gradually with the decrease of water temperature.