We saw two of these, both on night dives at Melasti and Pura Segara. This appears to be the species figured on Sea Slugs of Hawai'i as Aplylsia reticulata, and we have seen it in Lembeh Strait, Sulawesi, as well.
A specimen below from Amed differs a bit in coloration, but seems likely to be a variation of the same species.
Created 7 June 2013
Updated 30 October 2021