The Northern Sea Fan, or Swiftia pallida, is a horny coral restricted to north western coasts of the UK. It is usually about 10cms high but can grow to perhaps twice this. It is usually white but can also be grey and mat at times show a touch of pink. Usually seen below a depth of 15m, it lives attached to cliffs and boulders where there is a reasonable tidal flow. The coral polyps feed on organisms they catch as the water flows through the fan.
Muck, Small Isles, W. Scotland