Which parts of oysters are not edible?

When consuming oysters, one should generally avoid eating the oyster shell, gills, intestines, immature eggs, and contaminated parts. Detailed explanations are as follows:

1. Oyster Shell: The oyster shell is hard and mainly composed of calcium carbonate, which cannot be digested or absorbed by the human body. The flesh should be removed from the shell before consumption. Accidental ingestion of broken shell fragments may scratch the mucous membranes of the mouth, esophagus, or stomach, so the shell is absolutely inedible.

2. Oyster Gills: Located on both sides of the oyster meat, the gills are feather-like organs used for filtering seawater and respiration. They can easily accumulate sand, bacteria, and microorganisms, are difficult to clean, and have a coarse texture. Consuming them may affect taste and increase the risk of gastrointestinal discomfort. It is recommended to remove the gills before eating the oyster meat.

3. Oyster Intestine: The intestine is the digestive tract of the oyster, usually coiled beneath the meat, appearing as a black or dark-colored tube. It may contain undigested algae, sand, and metabolic waste, and carries a high bacterial load. It should be carefully removed before consumption to avoid gastrointestinal issues caused by impurities and bacteria.

4. Immature Oyster Eggs: During the breeding season, oysters develop eggs inside their bodies. Immature eggs are harder in texture and may appear greenish or yellowish. They have poor taste and are difficult to digest. Additionally, immature eggs may carry more parasites or bacteria. For safety and better taste, they are not recommended for consumption.

5. Contaminated Parts: If the oyster's growing environment is polluted, its surface or internal tissues may accumulate heavy metals, toxins, or harmful microorganisms. Before consumption, inspect the oyster meat for unusual odors, discoloration, or abnormal mucus. If any contamination is detected, discard both the affected part and the entire oyster.

Oysters should be thoroughly cleaned before consumption. It is recommended to cook them fully using methods such as steaming or roasting, and to avoid eating them raw. When purchasing, choose fresh, live oysters from reliable sources. If symptoms such as abdominal pain or diarrhea occur after consumption, seek medical attention promptly.