Jellyfish are classified as the genus Jellyfish under the class Jellyfish, and the range of jellyfish is larger than that of jellyfish. Jellyfish is just one kind of jellyfish. These animals belong to the phylum coelenterata. Coelenterates are a branch of the animal kingdom. It is the most primitive metazoan, with radiation or two radiation symmetries and only two germ layers. There are about 65,438+0,000 species of jellyfish, which belong to the genus Jellyfish, and the range of jellyfish is larger than that of jellyfish. Jellyfish is just one kind of jellyfish. These animals belong to the phylum coelenterata. The body wall of coelenterates consists of ectoderm, endoderm and mesoderm. The whole body cavity surrounded by endoderm is called digestive circulation cavity. One end of the cavity is the mouth, and the other end is closed without anus. There are stinging cells in the body wall, so it is also called stinging animals. The skeleton of coelenterates is mainly exoskeleton, which has the function of support and protection. It is mainly composed of chitin, keratin and calcium. Many corals have spicules or axes, which exist in the mesothelium or protrude from the body surface.