The biotic factors of a coral reef include animals, coral, plants and some forms of bacteria. These biotic factors cover a spread of many different species. Like many other systems in nature, coral reefs require this diversity of life in order to maintain stability in their populations. There is some interplay of biotic and abiotic factors in a coral reef.
According to Everday Life, a coral reef serves as a home to many different types of coral. Coral is a small type of polyp that reproduces and forms colonies. When the polyps die and leave their calcium carbonate shells behind, they form the basis of the coral itself.
This setting is home to more than just polyps, however. Animals, such as sea turtles, sea urchins, fish and some crabs, as well as small animals such as plankton, also live in coral reefs. There are also predatory animals, like sharks, eels and barracudas. Dolphins and some sea birds frequent these locations as well.
With all this activity, coral reefs become natural havens for different types of bacteria. This bacteria breaks down dead organic material and converts it to energy that other organisms can consume. Autotrophs can convert dead organic matter into energy, and they also thrive in the coral reef.