Distribution: Uncommon in the Solitary Islands Marine Park. Endemic to New South Wales waters.

Ecological Notes: Frequents tidal rock pools and platforms, where it is often found crawling over rocks and algae. Recorded from a depth of at least 6 m.

Additional Notes: Found in association with similarly coloured encrusting food sponge, Clathria sp. A small species easily overlooked, it has an orange mantle with a close covering of colourless translucent caryophyllidia (spiculate tubercles – glass like spicules which project from the skin) giving the mantle a rough “furry” feel and appearance.  Grows to about 12 mm.

References: Gary Cobb, David Mullins, Nudibranchs Encyclopedia, 2nd Edition, 2015. Publishers Thomas Slone, Masalai Press and Tim Hochgrebe, Underwater Australasia. p.190.

Australian Museum, Sea Slug Forum. http://www.seaslugforum.net/find/rostarbu. Accessed 26/09/2018.