1.1.1. Types of Corals

Corals are classified as under:

1. Hard Corals: Hard corals, also known as stony corals, produce a rigid skeleton made of calcium carbonate in crystal form called aragonite. Hard corals are the primary reef- building corals. Hard corals consisting of hundreds to hundreds of thousands of individual polyps are cemented together by the calcium carbonate 'skeletons' they secrete. Living coral grow on top of the skeletons of their dead predecessors. Hard corals that form reefs are called hermatypiccoral.

2. Soft Corals: Soft coral, also known ahermatypic coral, do not produce a rigid calcium carbonate skeleton and do not form reefs, though they may be present in a reef ecosystem. Soft corals are also mostly colonial i.e. what appears to be a single large organism is actually a colony of individual polyps combined to form a larger structure. Soft coral colonies tend to resemble trees, bushes, fans, whips, and grasses.