•Coral Reefs support a large number of plants and animals.
•Coral Reefs are built by millions of tiny animals called polyps.
•Some coral polyp species receive more than 60% of their food from algae.
•Each coral colony begins life as a single polyp, which then reproduces itself as a single polyp, which then reproduces itself by budding or by dividing.
Types of coral reefs
There are eight main categories of corals: branching, corals with meandering ridges and valleys, massive or thick colonies, thin plates and crusts, solitary/isolated/free-living corals, coral with large, daytime expanded polyps, column corals and blue/fir/organ pipe/lace corals. Some examples of coral are found below:
Where are coral reefs found?
Special conditions are needed for reef-building corals. Coral reefs will only grow in waters warmer than 18oC, and no deeper than 50metres. Therefore coral reefs are limited to clear, shallow tropical seas found either side of the equator. Corals may not develop properly in waters that receive freshwater runoff or sediments from rivers.
Deputy Principal at a Sydney high school. Coordinating author of the new Geoactive book series.