Waratah Anemone

Found attached to boulders, overhangs and rocks, in cracks, crevices and shaded areas of shallow coral and rocky reefs. They open their tentacles when under water closing when the tide recedes.
Depth - Shallow
Widespread Indo-West Pacific - Australia, New Zealand

These anemones will fight for their space, with other species if they are in close proximity.
They are preyed upon by Pleurobranchaea maculata!

Sea Anemones are large solitary polyps which have no skeleton. They have a basal or pedal disc which helps them crawl and dig into place, for some, once in place it is virtually impossible to move. Other smaller anemones move around the reef to feed at night.
Most eat plankton, but they are capable of eating anything caught in their stinging tentacles including quite big fish.
The fringing tentacles are configured in six or multiples of six.
Some sea anemones have a symbiotic relationship with sea anemones and some live commensally with various crabs, shrimp and brittle stars.