Dead Man's Fingers, Alcyonium digitatum, are temperate water soft corals that live in thick, fleshy masses with finger-like projections. A single colony can be up to 200mm across and they are found from very shallow water to a depth of 50m. The extended polyps, which project into the water to catch plankton, give them the swollen, puffy appearance that results in their rather repulsive name. They develop best in areas of high tidal movement where the plankton flow is at its greatest and in some areas such as this one, huge cliffs and walls are completely dominated by them. They are either white, creamy-white or orange.
When the tide stops running, the polyps are retracted, changing the colony's appearance significantly. In the picture, those at the bottom illustrate this point. Similarly, from Autumn to late Winter, when there is little plankton in the water column, the Dead Man's Fingers shut down completely, stop feeding and shrink to maybe a third of their normal size. At this time they become overgrown with algae, hydroids and even anemones but as light levels start to pick up in the new year, they gradually expand again to take advantage of the new season's growth.
St. Abbs Marine Reserve, Berwickshire. Scotland