Cnidaria

Cnidaria is a diverse group of aquatic animals that includes jellyfish, corals, and sea anemones. They have soft, often gelatinous bodies and are characterized by specialized cells called cnidocytes, which contain stinging structures used for prey capture and defense. Cnidarians typically have a radial body plan, with tentacles surrounding their mouth. They can be free-swimming or attached to surfaces, and many form vital coral reefs. Their simple nerve and muscle systems allow basic movement and responses to their environment, making them important both ecologically and biologically.