- Corals are calcareous rocks, formed from the skeletons of minute sea animals, called polyps.
- The polyps extract calcium salts from seawater to form hard skeletons which protect their soft bodies.
- The corals live in colonies fastened to the rocky seafloor.
- Corals are examples of symbiotic relations which live with algae called zooxanthellae.
- Ideal conditions for coral growth
- Corals thrive in tropical waters between 30o N and 30o S latitudes.
- The ideal depths for coral growth are 45m to 55m below sea surface, where there is abundant sunlight available.
- The temperature of water should be around 20 degree Celsius.
- Clear salt water is suitable for coral growth.
- Adequate supply of oxygen and microscopic marine food, called plankton, is essential for growth and existence.
