Most of the books seem to have this exact species under the name Edwardsia pudica, but one site has a reference to this as a species of Mesacmaea. These are common on lagoon sandy reefs, sometimes in or near patches of Halimeda algae. They are rather sensitive, and very rapidly retract into a hole in the sand at the slightest disturbance. These could use some study to determine if the various color forms are indeed all one species.
The bright red color of this one is unusual, and the pattern of tentacles could make it something different.
Created 26 July 2018