There are two reasons:
One: As we all know, crabs are rich in protein, fat, phospholipids, vitamins and other nutrients. Protein and phospholipids in crabs will disappear in a short time, so the longer the preservation time, the lower the nutritional value.
Two: cooked crabs stored for a long time are easy to be contaminated by bacteria. Therefore, crabs should be burned and eaten now, not stored. In case you can't finish eating, the rest must be placed in a clean, cool and ventilated place. When eating, be sure to return to the pot and cook it thoroughly.