The three day of the crab is not bad. Generally, it is no problem for the living crab to tie up the back and live 5~6 days in the foam box with ice bags. Generally speaking, the better courier company will take cold chain transportation when transporting crabs, and it can also play a better preservation effect. Will crabs be bad after three days of prosperity? Crabs belong to soft armour class, Decapoda. They are crustaceans. Their bodies are protected by hard shells and breathe by gills. In terms of biological taxonomy, they are similar to shrimp, lobster and hermit crab.
Most kinds of crabs live in the sea or offshore areas, and some live in fresh water or land. Common crabs include Portunus, pelagic Portunus, green crab and Chinese mitten crab.
A small number of crabs grow and reproduce completely in fresh water. They mostly inhabit under the stones of mountain streams. A few crabs, such as ground crabs, can adapt to land life, live in wet mud caves, and migrate to the sea during breeding. （PangXieFaShunFengSanTianHuiHuaiMa）