I have been meaning to post this for a long time. While in Lembeh this past February, I took these two photos. I have looked in several books and asked a few people, most (but not all) agree this is a nudibranch, but none seem to have a positive ID for it. To me, it seems that rhinophores are readily visible. In the photos above it is hard to tell, but if you click on them and pull up the original size at my SmugMug site, it looks to me like it also has gills, but admittedly it is not clear. The specimen in question is partially transparent.
It's a flatworm Lucas. Many of them have cephalic tentacles which are very misleading!
It looks like an acotylean polyclad worm. Leslie, please correct me if I'm wrong.
Marli
It looks like a nudibranch something sat on. No idea what it is though.
It's a flatworm Lucas. Many of them have cephalic tentacles which are very misleading!
Leslie is right, it is a flatworm, possibly a Paraplanocera species
Have a look in "Marine Flatworms, The World of Polyclads" byLeslie Newman and Lester Cannon
