Comment from the photographer: Hi there!
Seems to be a Chromodoris, but I could not find a match neither with the Lembeh-List nor with the Chromodoris.
It's from Lembeh Strait, North Sulawesi, Indonesia, exact position is 1°28'26.39"N, 125°14'1.74"E
I would appreciate a proper identification. If the photo is useful for nudipixel website you might use it.
Thank you
Piero