What are corals?

They are animal organisms that live forming colonies, that is, a lot of individuals that associate with one another and share certain biological functions; each unit or individual is called a polyp. The most remarkable feature of these polyps is that they excrete a substance called calcium carbonate (CaCO3), which is responsible for forming a calcareous external skeleton (exoskeleton), giving the corals a rock-like consistency, which is why they are often mistaken for some kind of mineral.
The external skeleton of the corals protect the coral polyps, as most of their body is submerged inside the calcareous structure. A polyp's basic structure is like a cylinder with its lower end fixed to a hard surface, while the top end has a mouth-like opening surrounded by tentacles.
The polyps are usually withdrawn (hidden) inside their exoskeleton during the day, and, at night, they extend part of their upper end -where they have their mouth and tentacles- to feed. They can trap microorganisms with their tentacles and wave them towards their mouth. In the Pacific and Atlantic Oceans there are approximately 100 genera and 800 species of reef-forming corals. In Venezuela, 29 genera and 57 species have been recorded, the most common and easiest to find being the elkhorn coral (Acropora palmata), the staghorn coral (Acropora cervicornis), and the boulder star coral (Montstrea annularis).

Ground Floor