Yes oysters can keep well if they are stored properly. You should place them on ice immediately after purchase, if not they will spoil very quickly. Once placed on ice, store them there until ready use. Oysters do not need any special treatment before they are served, but they do need proper handling after purchase. Proper storage conditions include cold storage at 4°c (40f) or below, away from sunlight, humidity & moisture. They will last longer if stored properly as mentioned above.