Yellow Sea Fan

Details

Subergorgia suberosa, commonly called the yellow sea fan, is a gorgonian‑type soft coral (Octocorallia: Alcyonacea) forming planar, fan‑shaped colonies. Branches spread within a single plane to maximize exposure to prevailing currents for suspension feeding on plankton and organic particles.

Ecology & Biology

• Feeding: polyps capture zooplankton and particulates from flow; energy comes from heterotrophic feeding rather than heavy reliance on symbiotic algae.

• Reproduction: sexual broadcast spawning/planulation plus asexual fragmentation with re‑attachment to hard substrata.

• Attachment/orientation: colonies anchor to hard substrates (rock, dead coral) and orient their fan plane roughly perpendicular to the main current.

Identification

Colonies are typically yellow to orange‑yellow; a stout trunk gives rise to pinnate branching forming one or a few fan sheets. Surface pores house small eight‑tentacled polyps. The internal skeleton consists of a proteinaceous axis withcalcareous sclerites providing strength and flexibility.

Colony size & Longevity

• Fan height: commonly 30–100 cm; exceptional colonies to ~150+ cm.

• Fan width: commonly 20–80 cm (variable with space and flow).

• Life: long‑lived octocoral; colonies can persist for many years to decades on stable reefs.

Range & Habitat

Occurs on tropical–subtropical Indo‑Pacific outer reefs, slopes, walls and channels with moderate to strong currents, typically at ~10–40 m depth (and deeper). Prefers clear water and low sediment loads.

Threats & Conservation

• Physical damage from storms, anchoring, fishing gear entanglement and diver contact.

• Sedimentation/turbidity that clogs polyps and reduces feeding efficiency.

• Climate stress (warming and acidification) that may affect skeletal deposition and colony integrity.

IUCN: no widely accepted global assessment—marked here as Not Evaluated (NE). Recommended: current‑swept reef buffers, no‑anchor zones and responsible diving/photography codes.