cnidaires
Cnidarians are a phylum of aquatic animals that includes jellyfish, corals, sea anemones, and hydras. They are characterized by their radial symmetry and the presence of specialized stinging cells called cnidocytes, which they use to capture prey and defend themselves. These cells contain nematocysts, which are harpoon-like structures that can inject venom.
Cnidarians exhibit two primary body forms: the polyp, which is sessile and typically cylindrical, and the medusa,
The body of a cnidarian is very simple, consisting of a sac-like structure with a single opening
Cnidarians inhabit a wide range of marine and freshwater environments, from shallow coastal waters to the deep