Hypselodoris tryoni (Garret, 1873)
Probably at the southernmost limit of distribution in the Solitary Islands Marine Park. Widespread but at no time common. Found in Tanzania and Indo-West Pacific.
Often found in pairs, crawling one after the other, on reefs to a depth of 25 m. Feeds on sponges, in particular Dysidea fragilis.
The mottled light and dark tan body with spots and blue/purple marginal band is very similar to Goniobranchus leopardus but the purple/blue spots on H. tryoni are more numerous and solid in colour. Grows to 90 mm.
Gary Cobb, David Mullins, Nudibranchs Encyclopedia, 2nd Edition, 2015. Publishers Thomas Slone, Masalai Press and Tim Hochgrebe, Underwater Australasia. p.152.