How does the polyp make its skeleton?
The external surface of the polyp has some special cells called calicoblasts that can take dissolved calcium from seawater and construct a solid skeleton. The skeleton thus looks like a cup with side walls, a bottom and open at the top. 5. If the polyp is so small, then how come some corals look so big? What you look at and think is a coral is not one coral but a number of them growing together. If you look at a coral piece closely you will find a lot of pores on it. Each one was the place where one individual polyp lived. Every coral colony begins as a minute skeleton of one single polyp and then keeps on growing by adding more and more individuals. 6. If all coral colonies start from a single polyp, then how come there are so many varieties? Genetic diversity comes to play its role here. You know the tiger, the cat and the lion all belong to the same genus, yet are so different. Similarly, the shape and size of a coral colony is genetically determined. The forms that we commonly see
