Coral (also known as polyps) are a tiny organisms that live on the ocean floor. They often are found in groups but, are capable of surviving on their own. They are in the family of jellyfish and sea anemones. Their base is hard and their skeleton is made out of limestone. Coral forms into reefs when it starts to form. It attaches to a rock and buds. The buds spread out making little clones that form into coral. They attach together and form into what is called a colony. Once they attach, they last a long time. There are coral reefs that formed over 50 million years ago, that are still alive and are located all of the world. One of the few ways to kill coral, is temperature change. When it changes, stress is put on the coral and it kills it. If one dies, it can kill the colony, unless the stress is subsided. Other ways they can die re global warming, pollution and sedimentation. Coral is found in tropical temperatures.