Cnidaria
The cnidaria phylum about 10,000 species of animals. It mainly contains contains animals such as jellyfish,coral, anemones, and hydra. These creatures do not have any actual organs, but do have a primitive nervous system known as a neural net. Cnidaria members are carnivorous and feed on small forms of crustaceans. Cnidaria members are divided into two structural forms: polyp or medusa. Polyps often from large colonies by attaching to the sea floor, while, medusas are free swimming and have tentacles that hang from their bell shaped bodies. Cnidarians have bodies composed of only two layers of cells, the epidermis and gastrodermis. A jelly like known as mesoglea is sandwiched between the two. Cnidarians also have a single opening used for he intake of food and digestion of waste which leads into an area known as the gastrovascular cavity. Cnidarians also have the ability to regenerate, and can recover from injuries and actually reproduce asexually because of this.