This is clearly in the Goniobranchus preciosus / G. verrieri group. It differs from the former by its lack of a white or blue-white line at the margin and from the latter by the much darker color of the margin. It is the only individual found and may be an aberrant form of one of those two species. It was found on the Gugeegue sandspit at Kwajalein Atoll on 24 November 2008.
Created 24 November 2021