According to 39 Health Network, oysters may not open automatically after being cooked. The tightness of oyster shell is the function of the internal muscles of oyster. After the oyster is cooked, the muscles inside do denature, but it is not sure whether the oyster shell is tightened or relaxed. Therefore, after eating the oyster, it may not open its mouth automatically, or its shell may be tightened.

Oysters generally refer to oysters. Oyster is the general name of Pinctada and mollusk of Oyster family, commonly known as oyster, oyster and so on. Shells are nearly long, round and triangular, and their shapes are extremely irregular due to the influence of external environment.