Aspect: Greyish bush of branches opening up like a firework, each carrying pinnately arranged sub-branches that bear the polyps. These extend in opposite directions on either side of the sub-branches. Population: Common. Notable feature: There are scores of Sea Plumes varieties that are difficult to identify with certainty, unlike the Slimy Sea Plumes (q.v.) that stand out due to a tacky substance their branches exude. Environment: Generally on rock or stone in sandy bottom areas gently swept by currents, in shallow and semi-deep waters. Behaviour: Polyps often extend in daytime, but touching one will cause almost all others to retract instantaneously.
