Micromelo undatus (Bruguiere, 1792)
Uncommon to rare in the Solitary Islands Marine Park. Circumtropical distribution: South Africa, Red Sea to Hawaiian Islands, Caribbean, Japan. In Australia recorded from Exmouth in Western Australia, Queensland south to central New South Wales.
Found in shallow water rocky habitats, inter-tidal to at least 10 m depth. Feeds upon polychaete worms.
This small sea slug has many colour variations. It is distinguished by its bluish green colour with opaque white spots, and shell with undulating 3 (rarely 4) dark spiral and wavy intersecting axial lines. Toxins obtained from its food source are concentrated into its body. The animal cannot retract into its shell. Grows to 30 mm.
Gary Cobb, David Mullins, Nudibranchs Encyclopedia, 2nd Edition, 2015. Publishers Thomas Slone, Masalai Press and Tim Hochgrebe, Underwater Australasia. p.49.
Undersea Jewels, A colour guide to nudibranchs, Gary Cobb and Richard C Willan. Australian Biological Resources Study, Canberra, 2006. p.37.