A coral reef is not a plant nor an animal, it is an ecosystem. An ecosystem is a group of plants and animals that fit together in their own unique "Niches" or roles that keep the ecosystem running smoothly. In most cases, if you take one animal or plant species out of an ecosystem, it collapses.
Back to the coral reef. A coral reef contains both plants an animals, the most common plant in a coral reef is, yes, coral. Coral is an underwater plant that filter feeds, unlike most plants on the ground. Most plants above water(and some below) use a method of feeding called photosynthesis. This is turning sunlight, water, and oxygen into glucose, or sugar for the plant. Coral filter feeds, meaning they just sit there and filter water and absorb the nutrients directly from the water.
Sea Anemones, are an animal species found in coral reefs. Sea Anemones have long tendrils that sway in the water currents and as fish pass by, if they touch the tendrils, they get stung and usually die. They then drag the fish into its mouth which is located at the center of the sea anemone. Sea anemones usually spend most of their lives in one spot, they attach to a rock and sit there waiting for their prey. But they can move around and attach to a new rock.
Another type of animal that usually lurks in coral reefs are eels. Eels are snake like animals that live in the seas and have one single fin on top that run the length of their bodies. Unlike snakes, eels have a set of vicious sharp teeth ready to tear fish apart. Eels usually hide in holes and narrow caves in the coral. As an unexpected, and very unlucky fish swims by, the eel strikes out, sinking its teeth into its prey. It then drags the fish back into the cave and enjoys its meal.
Anti-Cancer and painkiller drugs have been developed from coral reef products. In developing countries, such as the Philippines, coral reefs can provide food and a means of living for people. Coral reefs also play an important role in the carbon cycle, since it contains plants that give off carbon dioxide, just like trees in forests. Taking out all the coral reefs in our oceans would be a catastrophic act and would lead to many, many disasters. We need to work on protecting and conserving our coral reefs if we want our children, and our grandchildren, and our great-grandchildren to experience the wonders of nature that we are experiencing right now.