Corals are ... by Sharrie
Corals are found in most of the world's seas, even in polar waters. However, only those which have symbiotic zooxanthellae (single-celled plants which live in the cells of the polyp tissues) & live in shallow, warm, tropical waters grow fast enough to form reefs.Coral reefs are hence only found in waters where the min temperature does not drop below about 18°C & grow fastest where the temperature is around 26°C. Light is required for the algae's photosynthesis. Hence, corals grow best in clear, shallow continental shelf waters (less than 50 m deep) & away from river influences.
