Live oysters should be consumed within a day or two of being purchased, but definitely before they die and spoil, while shucked oysters can generally be kept for about 4 to 7 days, as long as they are stored at temperatures below 35 degrees Fahrenheit to prevent bacteria growth. Do not consume live shellfish that have already died because dead shellfish can harbor a high concentration of bacteria that can cause disease.
Live shellfish need to be loosely covered with clean and damp paper towels or cloths that can help prevent them from drying out in the refrigerators. Do not store live oysters with ice as the melted water can end up killing them. Also, do not store live oysters in air-tight containers since the oysters can suffocate and die.