Corals

Corals are amazing animals! Their bodies are made of a group of polyps. Shallow corals also may have algae living inside them that make food by photosynthesis. Some corals may grow into large communities called reefs, which also harbor other species such as fish. Reef-building corals are called hard corals because their soft polyps form hard calcium carbonate surfaces. Soft corals remain flexible—sometimes, they’re confused for plants because of the way they look! Although many corals live in shallow, warm waters, some are well adapted to cold or deep ocean habitats.

Corals reproduce by spawning once or twice a year. Fertilized eggs develop into free-swimming larvae, which can land in new places. Coral polyps can also reproduce in place by budding off new polyps! Corals eat food made by the algae that grow with them, or they use their tentacles to sting and then sweep plankton or small animals toward their mouth.