Pleurobranchus peroni (Cuvier, 1804)

Distribution: 

Found throughout the Solitary Islands Marine Park but not commonly seen. Recorded from the Indo-West Pacific region, in Australia from Geraldton in Western Australia, around the tropical north to Jervis Bay in southern New South Wales.

Ecological Notes: 

Often found on undersides of rocks and coral slabs, depth range intertidal to at least 15 m. Feeds on ascidians, Ritterella sp.

Additional Notes: 

Dark polygonal rings around the pustules are one identifying feature of this species. Rhinophores may be difficult to see in larger specimens. Colour variable from pale whitish yellow through orange to dark red. Juveniles distinctly different, usually with translucent white body, pustules tipped in reddish/purple and mantle edged with yellow or orange. Internal shell in this species is transparent and usually absent in specimens over 60 mm in length. Grows to at least 80 mm.

References: 

Gary Cobb, David Mullins, Nudibranchs Encyclopedia, 2nd Edition, 2015. Publishers Thomas Slone, Masalai Press and Tim Hochgrebe, Underwater Australasia. pp.81-2

Australian Museum, Sea Slug Forum at http://www.seaslugforum.net/showall/pleupero accessed 08/04/2020.