The butter crab is a variant of the green crab.

Butter crabs only survive in areas where freshwater and saltwater meet, and are only found in Guangdong, Hong Kong and Macau. The appearance of the butter crab is the same as that of the green crab, but after steaming, the body of the butter crab is similar between red and yellow, and yellow grease can be seen at all joints, which looks attractive in color.

The Origin of Butter Crab

According to local connoisseurs, during the hot summer spawning season, mature butter crabs will inhabit the shallow riverbanks while laying eggs. At low tide, the fierce sunlight makes the water temperature on the shoal rise, the crab is stimulated, the crab paste inside the crab body breaks down into golden yellow oil, and then penetrate into all parts of the body, the whole crab will be full of butter, the crab body shows orange-yellow color, so it is known as the butter crab.

Refer to Baidu Encyclopedia - Butter Crab