Fauna
Invertebrate

Branching Fire Coral

Millepora alcicornis

Also known as Sea Ginger, Ginger Coral, Antler Fire Coral

Branching fire corals are colonial hydrozoans that build hard, stony skeletons, often encrusting over dead sea fans and rocky substrate before developing upright, antler-like branches. Specialized defensive polyps concealed within microscopic pores unleash potent stinging cells whenever touched, deterring grazers and delivering intense burning pain to human skin. Colonies depend heavily on endosymbiotic zooxanthellae for nutrition, flourishing across sun-drenched reef flats where surging currents bring continuous supplies of microscopic prey.

Reef-BuildingStingingTropical
Branching Fire Coral reference
Nhobgood Nick Hobgood / CC BY-SA 3.0 · cc-by-sa
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EndangeredConservation statusIUCN Red List categoriesLCNTVUENCREWEXEndangeredRed List categories, explained →
Key facts
Diet & preyCopepods, Invertebrate larvae, Microscopic zooplankton
Predators
  • Bearded fireworm
  • Hawksbill sea turtle
ThreatsOcean warming and coral bleaching, acidification, and storm damage
HabitatsShallow coral reefs, rocky reef crests, and lagoons
Life spanSeveral decades to over a century
Classification
  1. FamilyMilleporidae
  2. SpeciesMillepora alcicornis
Range & activity
Range data is not available yet.
Safe observation
Interaction riskVery high
  1. Low
  2. Moderate
  3. High
  4. Very high
Why interaction risk is very high
Nematocysts inject venom on contact, causing intense burning; maintain distance and never touch.
Why it is dangerous
Fine dactylozooids fire venomous harpoon-like nematocysts that penetrate skin, causing immediate burning pain, erythema, and localized swelling.
How to recognize a risky encounter
Look for mustard-yellow to light brown branching structures with distinctly pale, blunt tips and a finely pitted surface.
What to do
Never handle or brush against colonies; if stung, do not rub or rinse with fresh water, and apply vinegar promptly.
What to notice
Recognized by its branching, deer-antler growth habit and yellow-brown coloration amidst shallow reef zones.
Support conservation
Avoid anchoring near colonies or making contact with diving gear, as brittle branches break easily and take years to rebuild.
Responsible observation
  • Buoyancy Control: Maintain steady trim and keep fins well clear to avoid contact and skeletal damage.
  • First Aid Precaution: Rinse any accidental contact area with household vinegar to neutralize unfired stinging cells.
  • Observation Etiquette: Admire the fine branch morphology from at least a meter away to avoid wave surge collisions.
Related species
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