TWAInv4

Invertebrates, Algae and Vascular Plants of The Tropical West Atlantic: Bahamas to Brazil, Part 4

To: Part 1, Part 2, Part 3, Part 5, Part 6, Part 7, Part 8, Part 9,

Bob Fenner

Gorgonians, Sea Fans

Gorgonians, Order Gorgonacea: What the deuces are sea fans anyway? Those scraggly stick things you see in fish stores or hanging on the wall at The Seafood Restaurant? Well, sort of; those are actually only the vestiges (skeletons) of what were sea fans. Looking at a human skeleton, have you ever heard, "What a babe/hunk!"; probably not. If you think sea fans are attractive as dead remnants "you ain't seen nothing yet".

Most everyone has seen sea fans on the boob tube; even had a sea fan in their hand, Order Gorgonacea, as a skeleton turned into a piece of jewelry. If you've been diving in tropical seas, you've brushed by them "waving" in the current.

Encrusting Gorgonians

Family Briareidae:

Briareum sp. Blainville 1830. Briareum Soft Coral. Family Briareidae. Colonies to 10 cm. N. Sulawesi (Lembeh Strait) pic. These are encrusting species with off white tentacles and bright white centers. Easily cultured in established tanks with strong current and intense indirect lighting. Important to isolate from stony and soft corals as these gorgonians can overgrow and smother them.

Briareum asbestinum, Corky Sea Finger, Deadman's Fingers. Colonies made up of one or more erect cylindrical columns, with large "hairy" polyps, occasionally encrusting. Rods purple to gray in color, polyps lighter. Images below: An upright colony in the Bahamas and a more encrusting form in Tobago. Colored purplish rind of encrusting colony in Bahamas and close-up by Di in Cozumel.

Family Anthothelidae

Erythropodium caribaeorum, Encrusting Gorgonian. Form encrusting mats that look hairy when polyps are extended, smooth, light colored, like leather when retracted.

Diodogorgia nodulifera, Colorful Sea Rod. Occurs as branched and rod forms. Polyps in cone-shaped calyces on red to orange rinds/stalks. Polyps white. Bahamas and Tobago pix.

Eunicea mammosa, the Swollen-Knob Candelabrum. Tropical West Atlantic. To about a foot in height. Closely packed tubular calyces. Candelabrum like in appearance overall. Have tube-like calyces and candelabra-like colonies. Most are light gold in color. Exist in many types of reef environments. High to low light, water movement. Di pix in Cozumel. Below: Aquarium and Cozumel images.

Gorgonia flabellum, the Venus Sea Fan. Large fans of one plane whose branches are interlaced and roundish to squared off at angles to the fans surface in profile. Below: Bahamas, Belize close ups and big colony.

Gorgonia ventilana, the Common Sea Fan. Similar to the Venus Sea Fan (above), but with branches that are flattened in profile, not roundish. A close up of the skeleton of G. ventilana on the left, B. flabellum on right in the Bahamas. Both mainly purple, but varying to whites, yellows, as second close up (Bahamas) shows.

Muricea laxa, Delicate Spiny Sea Rod. Tall colonies that are bushy, branched in many planes, with hard calcyces (proturberances, spines...) that extend out and upward with branches. Whitish, yellowish. Aquarium photos.

Muriceopsis flavida, Rough Sea Plume. Bushy colonies made up of tall branches or many small branchlets that extend in all directions (not uni-planar). St. Lucia pic.

Plexaura homomalla, Black Sea Rod. Bushy, planar colonies. Usually branch laterally (versus dichotomously). Have light brown to yellow polyps against dark brown/black stalks/rinds. Bahamas pix.

Plexaura nutans, Giant Slit-Pore Sea Rod. Tall colonies with thick stalks, not much branching. When closed, polyp openings like small open, raised slits. Tobago image.

Pseudoplexaura sp. Porous Sea Rods. Definitive genus detail are small openings in rind when polyps are retracted. Variable in appearance, color. Mostly dichotomous asymmetrical branch division. Brown, grey, tan to light purplish in color. Below: Tobago and two Cozumel images.

Pseudopterygorgia sp., Sea Plumes. Tall (to seven feet), bushy plumes of branches that are pinnately branching in single planes. Often purple, other times brown to yellowish. Tobago, Belize and Cozumel close-up (Di.F) pix.

Pseudopterygorgia bipinnata, Bipinnate Sea Plume. Colonies as single planes of bilaterally arranged branchlets. Usually purple, sometimes yellow to white. One of the most popular aquarium Sea Fans due to its beauty, small size (to two feet tall in the wild) and relative hardiness (when collected, held, shipped properly). Bahamas photos showing open and closed polyp colonies. See above/top for aquarium image at title.

Pterogorgia citrina, the Yellow Sea Whip. S.O. Holaxonia, Family Gorgoniidae. Tropical West Atlantic; abundant at times. Smallish, bushy colonies whose branches are flat, narrow, polyps along lateral edge . Branches variable in color. Di.F pic in Cozumel.

Pterogorgia guadalupensis, the Grooved-Blade Sea Whip. Tropical West Atlantic. To two feet in height, branches to 1/2" diameter. Appears uniplanar in view, with branches bearing a distinct groove in middle, tapering toward ends. Polyps extend from a common groove along edges. Di.F pic in Cozumel.

To: Part 1, Part 2, Part 3, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14, Part 15,

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