Invertebrates
Gorgonian
Gorgonacea · also called sea fan, sea whip
Angled precisely across a steady reef current, a gorgonian’s flat, branching fan barely sways as thousands of tiny polyps along its surface reach out to capture plankton drifting past. The whole structure bends slightly with the flow rather than resisting it outright, a flexibility no hard coral can match.
Overview
Gorgonians, order Gorgonacea, are soft coral relatives found across coral reef and rocky coastal habitat in oceans worldwide. Their flexible, fan-shaped colonies and efficient current-facing filter-feeding strategy make them a distinctive and ecologically important reef structure.
Built to bend, not break
Where hard corals rely on rigid calcium carbonate skeletons for structure, a gorgonian trades some of that rigidity for flexibility, an internal protein skeleton that lets the whole fan sway gently with the current instead of standing perfectly still against it.
Status
Not Evaluated — most individual species lack formal assessment, though reef degradation and ocean warming are considered general threats across the group.
Gorgonian: common questions
Why do gorgonians grow in a flat fan shape?
A gorgonian colony typically grows in a flat, branching fan shape oriented perpendicular to the prevailing water current, an arrangement that maximises the surface area exposed to passing plankton, allowing the colony's many small polyps to filter feed as efficiently as possible from the water flowing past.
Is a gorgonian a hard coral or a soft coral?
A gorgonian is generally considered a soft coral relative, since unlike hard corals, which build a rigid calcium carbonate skeleton, a gorgonian is supported by a flexible internal skeleton made largely of a protein material, allowing the colony to bend somewhat with passing water current rather than remaining perfectly rigid.
What lives on or around a gorgonian colony?
A gorgonian colony provides important structural habitat for numerous other reef species, including small fish, crustaceans, and other invertebrates that shelter among its branches or attach directly to its flexible skeleton, making a single large colony a small ecosystem in its own right.
How long can a gorgonian colony live?
Many gorgonian species grow relatively slowly but can live for a considerable number of years, with some larger colonies representing decades of gradual branching growth, making an established gorgonian a genuinely long-term structural feature of the reef it inhabits.