Crab in the cage in the sea will die. According to the relevant information query can be known, the crab can not live in the oxygen content is too low in the water, the crab will be kept in the water does not flow, do not increase the oxygen, to be slowly depleted of oxygen, about 4 hours later, the crab will be too low oxygen content and death, oxygen, preservation of time can be a little longer. Crabs, also known as crabs, arthropods phylum Mollusca. The number of genetic material in this group of organisms is complex and has great variability, often up to more than 100 pairs. Common crabs include hairy crabs (river crabs, hairy crabs, clear-water crabs), pike crabs, and so on. China's crab resources are very rich, including the lower reaches of the Yangtze River, Gucheng Lake hairy crabs, Taihu Lake hairy crabs, Gaoyou Lake hairy crabs, Yangcheng Lake hairy crabs, Crab House hairy crabs, Xinghua hairy crabs, Hongze Lake hairy crabs produced by the hairy crabs for the top quality.