Crab (pángxiè): animal kingdom, arthropod, crustacea, mollusk, soft armor, DECAPODA, Gastropoda, Anura.
It is a crustacean. Its body is protected by a hard shell and breathes through its gills. Taxonomically, it is the same kind of animal as shrimp, lobster and hermit crab.
Crabs, also known as Eriocheir sinensis, Portunus trituberculatus and Scylla, belong to crustaceans. There are more than 500 kinds of crabs, which can be roughly divided into two categories: one is sea crabs and the other is river crabs. Eriocheir sinensis is divided into three types: Liaohe River system, Yellow River system and Yangtze River system.
Autumn culture
1, water quality improvement? . Water quality management in autumn is particularly important, and biological agents should be used to regulate water quality in time to avoid molting period. On the one hand, supplementary application of quicklime, generally per mu per meter water depth 10kg, lasts for 20 ~ 30 days, and is evenly spread in the whole pond; On the other hand, calcium dihydrogen phosphate is supplemented once per mu per meter of water depth to promote the benign transformation of substance microcirculation in water and the absorption and utilization of phosphorus and calcium necessary for crab molting.
2. Water level adjustment. When the water temperature in the crab pond gradually drops and stabilizes below 28℃, adjust the water level in time to keep the average water depth at1~1.2m. Water injection and drainage are stronger than in summer, usually once every 3 ~ 5 days.
Step 3 feed the bait. Animal bait should be fed in time according to the temperature change and the growth of river crabs, so as not to start eating meat too early or delay time. It is easy to precocious puberty too early. Some crabs were very small after the last molting, and even a few died in 10. At the same time, too high temperature will make the water quality worse, affect the normal growth and induce diseases. If it is too late, you may only molt once, which will limit the listing specifications and reduce the weight gain.