Squid, also known as soft fish, gun squid, is the mollusc phylum, cephalopods, sheaths subclass, ten wrasses, tube squid order open-eyed suborder. Squid is a mollusk, there is no hard shell on the outside, and squid look similar but have a large hard shell on the back of the animal for cuttlefish.

Cuttlefish is a shellfish, also known as squid fish, cuttlefish, gogglefish, etc., belonging to the phylum Mollusca, cephalopods, decapods, squid family. Cuttlefish shell both squid plate, the scientific name of the squid bone, is also commonly used in traditional Chinese medicine, called cuttlebone.

Cuttlebone for the squid family animals needleless squid or golden squid dry inner shell, flat long oval, thick in the middle, thin edge, 9 to 14 centimeters long, about three centimeters wide, about 1, 3 centimeters thick. The cuttlebone has a porcelain-white ridged elevation on the dorsal surface, slightly reddish on both sides, and a white ventral surface with horny, translucent edges. Cuttlebone loose texture, easy to break, with astringent hemostasis, acid control pain, dampness and astringent sores efficacy, commonly used in the main treatment of ulcer disease, injury bleeding and vomiting blood and other symptoms.