There are a number of species (or color varieties) of Didemnum under rocks along the lagoon reef.
The purple Didemnum below is nearly surrounded by a dark pink species in the same genus.
The photos below show several species of Didemnum along with other encrusting organisms.
Didemnum tunicates are the favored prey of a number of snails in the genus Lamellaria. Sometimes the snail blends in well with the substrate, but sometimes not, such as this orange Lamellaria in the midst of the purple Didemnum below.
Another Lamellaria (the pink blob in the center of the photo) on prey Didemnum.
Another Lamellaria.
This may be a young colony of the purple Didemnum.
Created 31 March 2019