About Goniobranchus preciosus (Kelaart, 1858)
Goniobranchus preciosus, first described by Kelaart in 1858, has a white mantle with three colored lines along its edge. The outermost edge of the mantle is a thin white line, with a dark red band located inside this white line, and a yellow band inside the dark red band. The clubs of its rhinophores are brown, with white edges on the lamellae, and the gill leaves are also brown, with white markings. The body length of this species ranges from 15 mm to 30 mm. Goniobranchus preciosus is very similar in appearance to Goniobranchus verrieri, and can be most easily distinguished from that species by its white mantle margin. It is also similar to Goniobranchus trimarginatus, but Goniobranchus trimarginatus has white gills and rhinophores, and red speckles on the middle of its back. The type locality of Goniobranchus preciosus is Ceylon, which is now Sri Lanka. The species has been reported across a wide area of the Indo-West Pacific region.
