Distribution: Rare in the Solitary Islands Marine Park. Found throughout tropical Indo-West Pacific. In Australia recorded from Western Australia, southern Queensland and northern New South Wales.

Ecological Notes: Found in rocky reef areas to a depth of 25 m. Feeds on sponges.

Additional Notes: Background colour can vary from reddish purple to pinkish orange, with a broad creamy white mid line band running from the rhinophores to gill pocket. This band always encircles the gills and may be broken midway along its length. The mantle edge has a broad creamy white edge, on the inside of which are a series of reddish purple streaks or smudges. Both gills and rhinophores are translucent with orange colouration. Egg rings are large, conspicuous and coloured like the mantle. Grows to 25 mm.

References: Gary Cobb, David Mullins, Nudibranchs Encyclopedia, 2nd Edition, 2015. Publishers Thomas Slone, Masalai Press and Tim Hochgrebe, Underwater Australasia. p.158.

Australian Museum, Sea Slug Forum. http://www.seaslugforum.net/find/noumnorb. Accessed 08/09/2018.