The violet sponge Chelonaplysilla violacea is common under rocks or exposed on the reef. Under rocks, this species is usually encrusting on hard surfaces, but when exposed it often grows into a clump that is sometimes not attached to the bottom.
Several different kinds of nudibranchs eating this violet sponge. For examples eaten by Goniobranchus geometricus.
Distribution: The species has been reported from both sides of the Pacific. Given the paucity of morphological characters, it remains to be established whether these wide ranging populations all belong to a single species