Nudibranch feeding - Flabellina lineata

The sea slug (or Nudibranch), Flabellina lineata is a very specialised feeder and only preys on Tubularia hydroids - here on Tubularia indivisa. It climbs the stem and consumes their flower-like polyp heads. It is quite common to find whole areas of Tubularia with no polyps remaining due to the activities of this animal.