Let’s explore the different anatomical parts of the coral polyp! Remember each structure has a function.
To explore the different anatomical structures, either click on the coral polyp or navigate through the sidebar.
Corals are invertebrates (animals that do not possess a backbone) and they are in the Phylum Cnidaria. Anemones, hydrozoans, and jellyfish also belong to this phylum. There are two main subclasses of corals. The Subclass Octocorallia contains soft corals, while the Subclass Hexacorallia are stony or hard corals. We are going to take a closer look at the anatomy of hard corals. These corals are important in building the structure of the reef and providing homes to many animals.
Often corals live in colonies, though some are solitary. Each individual animal is called a polyp. Depending on the size and age of the coral, there can be hundreds or even thousands of polyps present.
Corals are able to share nutrients with each other. They pass these nutrients back and forth through gastrovascular canals that are located in the coenosarc.
Most corals are sessile meaning they cannot move to obtain food. Instead they stick out tentacles to catch prey items such as zooplankton and other food particles. The prey is dependent on the size of the coral polyp. Then they use their tentacles to place the prey into their mouths. In other lessons, you will learn other ways that corals feed.
Nematocysts are stinging cells that help aid corals in feeding. When the cell is stimulated a barb shoots out of the capsule, unraveling the coil, and impaling or wrapping around the prey item. The barb contains toxins that subdue its victim.