Crab gills: gills are the respiratory organs of crabs. They breathe underwater and filter out many impurities, so they are very dirty and can't be eaten.

Crab stomach: Crabs are omnivores. Besides eating zooplankton and aquatic plants, they also eat rotting animal carcasses and microorganisms, so crabs have dirty stomachs.

Crab heart: Crab heart grows between crab meat and crab roe and is connected with crab stomach. Crab heart is one of the main parasitic areas of parasites, and it is extremely cold and inedible.