There are a large number of bacteria and parasites in the crabs' body, which are unfavorable for survival as attrition is reduced in an airtight environment. To preserve fresh crabs on a daily basis, you can bundle them into a preservation box, cover them with a wet towel and keep them in the refrigerator, or you can put them in water with small fish and shrimp to preserve them.

The crab belongs to the class Mollusca, order Decapoda, and is a 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 the sea or offshore areas, there are also some inhabiting freshwater or land.