Title

Gorgonia flabellum (Linnaeus, 1758)

Photographer

Charles Messing, Nova Southeastern University

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Family

Gorgoniidae

Common Name(s)

Purple sea fan

Colony Form

Monoplanar fan to at least 1 m across.

Axis

Flattened at right angles to plane of fan on small ascending and interconnecting branchlets (pinnules).

Branches

Major ascending branches tapering toward tips; smaller ascending and interconnecting branchlets (pinnules) flattened at right angles to plane of fan. Meshes polygonal, squarish or irregular.

Apertures

Round or oval, chiefly on sides of small branchlets.

Mucus

None

Color

Usually yellow; sometimes lavender or grey.

Sclerites

Polyp armature: small rods rarely longer than 0.06 mm. Body wall: acute spindles to 0.14 mm long; scaphoids (curved sclerites) usually with complex tubercles on convex side, to 0.1 mm long.

Habitat

Crests and seaward slopes of shallow reefs exposed to surge, as shallow as 1 m and rare below 10 m.

Distribution

Bahamas, Caribbean Sea; uncommon in South Florida.

Notes

Fans grow perpendicular to current and oscillating flow to maximize their surface area for feeding. G. flabellum with numerous small branchlets arising from one or both sides of fan have been called form occatoria, but this has no phylogenetic significance. G. ventalina is preyed upon by several gastropods, including the ovulidsCyphoma gibbosum, Cybovula acicularis, Simnialena uniplicata, and the nudibranch Tritonia hamnerorum. G. flabellum is also infected by the fungus Aspergillus sydowii, which causes necrosis and may kill the entire fan.

References

Bayer (1961), Cairns (1977), Wainwright & Dillon (1969), Gosliner & Ghiselin (1987), Cronin et al. (1995), Humann & DeLoach (2002), Sanchez & Wirshing (2005), Murdoch (2006), Toledo-Hernandez et al. (2008), Reijnen et al. (2010).

Gorgonia flabellum; Iciligorgia schrammi

Date Taken

4-11-2016