The seas of the tropical regions, where the water temperature is around 25 degrees, are an ideal environment for the madrepora: this name is used to indicate different varieties of animals, formed by hundreds of small polyps, belonging to the coelenterate type, that live in colonies with calcareous structures that branch into many different shapes. Many coral species live together and form a shelter for a large number of sea inhabitants such as the clownfish, surgeonfish, gigantic molluscs.... crustaceans, triggerfish and sea urchins are a few of the creatures that populate the coral barrier.