Deep-water sea fan, Black sea fan
Monoplanar stiff fan with dichotomous branches not interconnected; to ~1 m tall.
Flattened in plane of fan.
Flattened in plane of fan, dichotomous, not interconnected, 3-5 mm across. Secondary branches and unbranched twigs usually bent. Terminal twigs along fan periphery usually forked. Edges of twig ends folded over and joined so that twig tips are indented or grooved (=fistulose).
Polyps restricted to sides of branches. Calices are low oval or slitlike mounds with eight lobes.
Red-brown, copper, dark brown or grey. Often appearing black in situ. Usually light brown when dried.
Polyp armature: flattened, slightly curved spindles to 0.5 mm long, arranged in eight series of inverted V’s (“en chevron”). Outer layer: chiefly elongate spindles 0.5–0.6 mm long, with ornamentation ranging from scattered small thorns to crowded tubercles. Inner layer: smooth to slightly warty, extremely slender needles 0.5–0.7 mm long.
Deeper reefs, commonly along slopes, walls, crevices and canyons exposed to currents. Depth range: 3-368 m, usually below ~15 m.
Georgia to Brazil, Bahamas, Caribbean Sea.