This strange combination of tentacles and tissue is an unusual anemone, Paracorynactis hoplites, shown retracted to around 5 inches (12.5cm). It is often seen attached to the edges and undersides of small rocky overhangs with tentacles reaching downwards where it captures passing short-spined sea urchins and sea stars, notably including the notorious crown-of-thorns. The orange ruffles appear to be part of its digestive system.
8 May 2016