Animal profile

Fire Coral

Millepora alcicornis

HydrozoaShallow tropical reefs, often encrusting other corals and gorgonians

Field profile

Fire coral forms mustard-coloured encrusting or branching calcareous colonies on shallow reefs. It looks like a stony coral but belongs to a different class. Contact produces an immediate burning sting, which is the origin of its name.

Published field notes

2026-03-02

Fire Coral

Fire coral is a hydroid wearing a coral's skeleton

Millepora builds a hard limestone structure and lives on reefs, but it is a hydrozoan, closer to Portuguese man o' war and hydra than to the stony corals it grows over. Its stinging polyps sit in pores too small to see.

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