There are a number of species (or color varieties) of Didemnum under rocks along lagoon and seaward reefs.
Didemnum can puff itself up a bit with water, causing it to look like little volcanos as in the above photo. If it pushes out that water, it flattens out against the rock.
A dark red Lamellaria snail feeding on a pink Didemnum.
Didemnum and other encrusting organisms on the underside of a rock on the intertidal reef.
Created 31 March 2019