Stony Corals at Bluff Island,Sai Kung

What is stony coral?

• Corals in order Scleractinia and possess solid calcium carbonate skeleton

• Usually bear 12 tentacles which are always number in multiples of six

• Some corals in class Hydrozoa and in sub-class Octocorallia can also deposit hard skeleton, but they have distinctive skeleton structure and number of tentacles

• Approximately 800 known species of stony corals