Many sources say that coral polyps hide down in little holes. That couldn't be more wrong. Polyps are so soft-bodied it's hard to imagine. Their skeleton is formed underneath them, like people have bones inside them. And coral skeletons are sharp as razors. The lightest human touch pushes coral's flesh into their skeleton, causing much harm.
Polyps grow from one single baby polyp that, once old enough, "buds" little polyps on their edge. Sort of like how one little bit of grass spreads. They are always connected like a rug, and they share food and bodily fluids. This 'rug' of polyps lives covering the hard white part of the coral that you find for sale in some stores, ugh. Skeletons as ornaments?
Here are the same polyps, ten weeks later. They're making babies, clones if you will. And some have their tentacles extended, waiting to catch passing food. The bare skeletons have been overgrown by algae.
The polyps are a little pale because the sea was too warm when the photo was taken.
Thanks for stopping by, time to go for a dive and see what I can find...