If it is put in water without oxygenation can live 4 hours.

Crab is not hydrophilic, can not put the crab in the water, which will cause the death of the crab, in the case of preservation of reasonable, the crab put a little water to maintain humidity, can survive for about 10 days, some people raise aquatic products, the survival time of the crab will be longer.

Crab: animal kingdom, phylum Arthropoda, crustacean subphylum, soft armor, true soft armor subclass, decapods, abdominal embryo suborder, short tail under the order. It is a crustacean (crustacean) whose body is protected by a hard shell and breathes by gills. In biological taxonomy, it is the same kind of animal as shrimp, lobster, and hermit crab.

The vast majority of species of crabs live in or near the sea, with some inhabiting freshwater or land. They rely on their mother crabs to give birth to their young, and each time she lays many eggs, which can number in the millions or more. Crabs rely on geomagnetic fields for orientation. These organisms have a complex and highly variable number of genetic material, often up to 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, with the lower reaches of the Yangtze River, the Gucheng Lake hairy crabs, Taihu Lake hairy crabs, Gaoyou Lake hairy crabs, Yangcheng Lake hairy crabs, Crab House hairy crabs, hairy crabs, Xinghua hairy crabs, Hongze Lake hairy crabs produced by hairy crabs for the top quality.