River crabs can survive for about a week after you buy them at home. After you buy the crabs, put them in a net and tie it tightly, or put them in a plastic bag with a few holes for ventilation, and then put it in the refrigerator in the fresh layer, which can be stored for a week. It is important to note that you can't use tap water to clean the river crabs after you buy them, otherwise it may cause them to die.