Boloceroides mcmurrichi is known as a swimming anemone. While usually seen attached to algae or other substrates in lagoon Halimeda patches, when disturbed they will release their hold on the bottom and swim up into the water by sort of pulsing their entire body. They are generally small, to about 30mm in diameter.
The two below happened to be attached to the sea cucumber Thelenota ananas.
Created 26 July 2018