甲壳纲，关公蟹科。关公蟹科是世界海洋广布的一个类群，该科在中国近海约有19种。关公蟹主要栖息于水深8～120米的浅海底上，常用后两对步足钩住一片贝壳或其他物体置于背部，每当受惊或遇险肘，把体藏入壳下或弃壳而逃。
学名：Dorippe
英文名：musk crab
This species belongs to the family of Dorippidae which is the group of the vast distribution in the world, there are 19 species in Chinese offshore.Mainly live in the water depth of 8 to 120 meters on the shallow sea, commonly use the last two pairs of foot to hook a shell or other objects which is placed on its back.Whenever it’s frightened or in distress, the body will hide into the shell or abandoned its shell to fled.