He also built the cherry stand on which it sits. Though most of the aquarium's inhabitants may look like plants or rocks, the strange creatures Williams raises are forms of coral, living creatures with skeletons of calcium carbonate. Like other creatures, they grow, multiply, have daily cycles, fight for living room and even occasionally destroy one another. The rock is from Fiji and the sand is from the Caribbean. A piece of coral is not just one creature, but several.
Every little polyp is a separate animal.
I started with little tiny pieces and they've grown in the tank. The tongue coral has tentacles that come out occasionally. The brain coral swells overnight and is most beautiful in the morning. The later in the day it gets, the more it closes down. Most corals have a sting, harmless to humans, which can damage or even kill encroaching neighbors.