Living Colors of a Coral Reef

Coral reefs are found near many islands in warm, shallow seas around the world. These colorful, rocky ridges look like dazzling underwater rainbows, but they work like busy cities. There are homes, schools, places to eat, gardens—even tourists!

Coral reefs are made up of—coral. Coral may look like an exotic flower, but it's really a living, breathing animal. The fat petals are tentacles. The center of the “flower” is the coral's mouth. Tiny stingers in the tentacles protect the coral and catch food.

Many corals are soft on the inside but have a hard outer covering called an exoskeleton. When these corals die, their exoskeletons are left behind to become part of the reef. A coral reef is built up of many layers of exoskeletons covered by a thin layer of living coral. It takes hundreds of years to build up a coral reef, and some are thousands of miles long!

All great cities have great food. In a coral reef, squid, clams, and other sea creatures eat and are eaten. Big fish eat small fish. At night, corals feed on little fish and tiny plants and animals called plankton.

You can even find little gardens in a coral reef. Damselfish eat a slimy green stuff called algae. They could hunt around for meals, but some damselfish find and protect their own tiny algae gardens.

Every interesting city has tourists, and the reef is no exception. Visitors include sharks, sea turtles, sea snakes, and people. People? It's true. The vivid colors and amazing animals make coral reefs popular places for human sightseers. In fact, you can find more different kinds of plants and animals in a coral reef than almost anywhere else on Earth!

But people need to be considerate visitors. Coral reefs are beautiful—but they are also delicate. It is important to protect coral reefs around the world, to help these underwater cities thrive for years to come.


A simple living thing that grows in water.

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  1. What are some of the living things found around coral reefs?
    [anno: Answers may vary but could include living corals, fish, eels, sharks, people, algae, and turtles.]
  2. What happens to coral when it dies?
    [anno: When a layer of coral dies, it leaves behind its exoskeleton. A new layer grows on top of the nonliving layer.]
  3. Coral reefs grow slowly over many years. Why would it be bad if everyone who visited the reefs took away pieces of coral?
    [anno: It would be bad if everyone took pieces of coral because it takes the reef a long time to build new coral. The reef might be destroyed, and many homes for animals would be lost.]