Family: Plexauridae

Common Name(s): Pinnate spiny sea fan

Colony Form: Tall, fan-shaped, pinnately branched in one plane, to 45 cm tall.

Axis: Present

Branches: End branches stiff, widely spaced, slightly enlarged at tips, to 50 mm long, usually 20-30 mm; arising from main stems at right angles but soon turning upward; occasionally interconnecting.

Apertures: Well spaced (not crowded), prominent, with pointed lower lip but no spike, directed upward toward branch tip.

Mucus: None

Color: Yellow or yellowish-brown; dries yellow to orange. Sclerites amber.

Sclerites: Outer layer and calices: spindles ranging from slender with fine thorns 0.2-0.3 mm long, to stout with tubercles on outer surface modified as blunt thorns but no strong spines, to 1.2 mm. Inner layer: acute spiny spindles near branch tips, 0.15-0.45 mm long; short capstans lower in colony, 0.15-0.35 mm.

Habitat: Moderate to deep forereefs at depths of 13-36 m.

Distribution: Carolinas, occasional on both coasts of Florida, northern Gulf of Mexico. Not reported from Bahamas or Caribbean Sea.

Notes: Similar to Muricea pinnata but distinguished by red color when alive; in M. pendula, the large pointed sclerites of calices lack a terminal spike, inner sclerites are larger and end branches thicker.

References: Bayer (1961), Humann and DeLoach (2002).

Similar Species: Muricea pinnata