Hard Corals
This group is made up of the hydrocorals and the stony corals. Both types of coral have hard skeletons made of calcium carbonate.

There are two kinds of hydrocorals: fire and lace corals. Fire coral, sometimes called stinging coral, gives you a painful, burning feeling when it touches your bare skin. The sting is not dangerous but the rash can itch for a few days. What makes fire coral sting? Microscopic hairs called nematocysts on the tentacles of the polyps are responsible for delivering the painful sting. Fire corals have two types of polyps: stinging polyps and feeding polyps.

Lace corals get their name because of their appearance; they produce many branched, hard, calcium carbonate skeletons. In the Caribbean there are three growth patterns: branching, blade and box. Lace corals also have feeding and stinging polyps. The polyps live in small pores in the skeleton. The pores look like cups. Lace corals are usually shades of purple, burgundy or lavender at the base, fading to pink and white out to the branches’ tips. Although lace corals can irritate bare, sensitive skin, their stinging cells are not as powerful as those of fire corals.

CONTINUE: Stony Corals »