1. The crab heart is a white hexagon, which is located under the black film jacket of the crab heart. Crab heart is inedible. 2. Crab stomach: Open the crab shell and see some crab roe on it. Crab stomach is hidden in crab roe and has crab excrement shell, so it is not recommended to eat. 3. Crab gills: Two rows of "small fans" open the crab shell, and two rows of gray fan-shaped soft tissues on the crab are crab gills. Crab gills are the respiratory system of crabs and should not be eaten. 4. Crab intestine: a black crab intestine from the crab stomach to the crab navel, located in an expandable triangle in the lower abdomen of the crab. When you open the triangle, you can see a black line connecting the crab's body at its top. There is crab excrement in the intestine. Extended information: Taboos for eating crabs Avoid eating crabs raw: The body surface, gills and gastrointestinal tract of crabs are covered with all kinds of bacteria and sludge. Crabs should be steamed thoroughly and cooked. Generally, it can be disinfected by heating for more than 30 minutes after boiling. Second, avoid eating dead crabs: buy dead crabs. Bacteria in the dead crab quickly proliferate and spread into the crab meat, decomposing amino acids in the crab meat and producing a large number of harmful substances. Eating dead crabs may cause vomiting, abdominal pain and diarrhea. Besides, don't buy crabs that are dying. Third, avoid eating cooked crabs for a long time: stored cooked crabs are easily contaminated by bacteria. So now the crab is going to burn and eat. In case you can't finish eating, the rest must be kept in a clean, cool and ventilated place (preferably in the refrigerator). Be sure to go back to the pot and cook it thoroughly when eating.