About Goniobranchus geometricus (Risbec, 1928)
Goniobranchus geometricus is a small nudibranch that can reach a maximum total length of 35 mm. This species has variable coloration: its base body color ranges from creamy brown to purple, its mantle is covered in numerous cream-colored bumps and has a white edge, and its gills and rhinophores range in color from white to greenish. It is very similar in appearance to Goniobranchus conchyliatus, but can be distinguished by the color of its rhinophores and gills: Goniobranchus geometricus has green-grey rhinophores and gills, while G. conchyliatus has red rhinophores and gills. This species was first described from specimens collected in New Caledonia. It can be found across the entire Indian Ocean and Western Pacific Ocean, at depths ranging from the intertidal zone down to 30 m (98 ft). Goniobranchus geometricus feeds on the sponge Chelonaplysilla violacea.
