phyllodesmium briareum, sea slug at a tropical coral reef. it looks almost like a skeleton

sea slug skeleton aeolid nudibranch marine gastropod mollusk facelinidae soft coral briareum violacea aquatic biodiversity closeup reef colorful diving photography invertebrate macro biology ecosystem life ocean phyllodesmium scuba tropical waters under the underwater yellowtipped philippines branch snail seaslug critter triangle creature critters in invertebrates mollusks