White Gorgonian

Eunicella singularis can grow to a height of about 70 cm (28 in) and a width of 70 cm (28 in). It has a branching structure, growing from a thickened base with a small number of nearly-vertical branches and a few side branches. The surface of the branches is smooth, with the calyces from which the polyps protrude being indistinct. The general colour is white and the polyps are translucent and yellowish-brown or olive.

Eunicella singularis is found in the western Mediterranean Sea and the Adriatic Sea at depths of 10 to 60 metres (33 to 197 ft). It mainly occurs on shallowly sloping rock surfaces which are often partially covered with sediment, but also on pebbles, shells or other objects surrounded by sediment. It favours well-lit locations.

In the Mediterranean Sea, Eunicella singularis is often overgrown by the soft coral Alcyonium coralloides which kills the sea fan's soft tissues as it spreads along the branches of its slow-growing host.

The nudibranch Marionia blainvillea feeds on this sea fan and, where their ranges overlap, so does the whip fan nudibranch (Tritonia nilsodhneri). The gastropod mollusc Simnia spelta mimics E. singularis and feeds and lays its eggs on its branches. The bare areas where the mollusc has removed the coenenchyme tissue soon become colonised by epibionts such as algae, tube worms, bryozoans, and colonial tunicates. The tissue may regrow and form cavities in which other organisms can flourish, thus forming a small but biodiverse community.