I tried to suggest "Pseudobiceros ferrugineus" but the suggestion wasn't found, only Pseudoceros ferrugineus. Apparently, Pseudobiceros ferrugineus (older name) and Pseudoceros ferrugineus are different names referring to the same flat worm. Deed (fuchsia) red colored flatworm with a narrow, yellow colored margin. Red color is the first to disappear below the surface, so it may appear purple, unless you use a light. Between the central body and the marginal band, a darker band may show. The center of the body contains a dense concentration of fine white spots. It can be found in parts of the Western Central Pacific, such as the Philippines, New Guinea, Hawaii and Eastern Australia. It can be found in coral rich areas, usually around colonial ascidians, in a depth range of 0-30 meters.
I spotted one during a dive here in Vanuatu but didn't have a camera with me at the time. Identifying it based on description alone was quite difficult. This website is awesome, it finally helped me figure out what I had seen. Well I hope! What do you think?
Oh nice, you really know your stuff! That whole Pseudobiceros / Pseudoceros name mess throws everyone off, so respect for figuring it out. And the red-drops-off-first thing so it looks purple without a light — love that.
Also… Vanuatu? Pretty cool — most lists only mention the Philippines, New Guinea, Hawaii and Eastern Australia, so you basically just added a new dot to the map. Guess these little guys get around way more than people think.
And thanks a ton for the kind words about the site, that honestly made our day — exactly what we were hoping it'd do.
Oh, and one thing: if you ever can't find a species on here, just give us a shout and we'll add it (this flatworm's a perfect example — I put it in myself). Either support@hanki.com or straight to me at paul@hanki.com. So next time you spot something cool, chuck it our way — we'd love to have it!
Reference image