Biscayne National Park

The Reef

Dive into the undersea realm of the coral reefs and you will discover a feast for the eyes. It is a living kaleidoscope of gaudy colors, bold patterns, intricate designs, and peculiar shapes. Alien, yet inviting, the life of the reefs excites and mystifies snorkelers and scientists alike.

The Reef Builders
Among the most puzzling creatures are the corals. Early biologists suspected they were plants. But each coral—brain, finger, or staghorn—is actually a colony of thousands of tiny, soft-bodied animals. These animals, called polyps, are relatives of the sea anemone and jellyfish. Rarely seen in the day, the polyps emerge from their hard, stony skeletons at night. It is then that they feed, catching drifting plankton in their outstreched tentacles.

These primitive, unassuming animals are the mighty master builders of the reefs. The creation of one reef requires the team effort of billions of individuals. Each extracts building material—calcium—from the sea, and uses it to make itself a protective tube-shaped skeleton. Together, hundreds of these skeletons make a coral. Many corals growing side by side and one on top of another, form a reef.

Corals are very particular about where they build reefs. Like the offshore seas of Biscayne, the water must be the right temperature (no lower than 68 degrees F), just the right depth (no deeper than 200 feet) and be clean and well-lit. Such conditions exist all along the Florida Keys in and south of Biscayne and in the Caribbean, as well as in some other tropical oceans.

An Undersea Metropolis
The reefs are the cities of the sea. In and around them lives a huge and diverse population of fish and other marine creatures. Every hole, every crack is a home for something. Some inhabitants like the Christmas tree worm, even live anchored to the coral. And there is food to satisfy all tastes. Corals are eaten by flamingo tongues, which are small snail-like mollusks, and fish. Fish are food for other fish, and, quite often, for seafood gourmets.

Published: 29 Apr 2002 | Last Updated: 15 Sep 2010
Details mentioned in this article were accurate at the time of publication


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