This appears to be a species of Flabellina. The single specimen known so far measured about 11mm and was in a Halimeda patch on a Kwajalein Atoll lagoon slope at about 22m depth. It is figured as Flabellina sp. 8 on the Sea Slug Forum. It also resembles Flabellina sp. e094 from the Marshalls, especially in the red dots around the base of the cerata, but there are enough differences to keep them separate for now.
Created 10 July 2011