Mustard-coloured with white branch tips. It is a hydrozoan rather than a true coral, and it grows over gorgonians and wrecks in the shape of whatever it has covered.
Colonies to about 50 cm, mustard-yellow to tan with pale branch tips, growing over gorgonians, wrecks and dead coral and taking the shape of whatever it has covered. That is the difficulty: it does not have one shape, and a fire coral that has grown over a sea fan looks like a sea fan.
It is a hydrozoan rather than a true coral, and the fine hair-like polyps that give it the pale tips carry the stinging cells. Contact produces immediate burning, a welt and itching that can last for days. It is the commonest sting on a Caribbean reef, and the reason is exactly that it does not look like an animal — people put a hand on it while steadying themselves. Vinegar rather than fresh water on the affected skin, and do not rub it.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.
