Uncommon in the Solitary Islands Marine Park. Members of the Family have been recorded throughout the Indo-West Pacific. In Australia recorded from islands off the north western coast of Western Australia, central Queensland south to Victoria, around Tasmania and including Middleton Reef and Lord Howe Island.
Frequent areas such as boulder shores, rocky reefs, and underwater installations such as piers where food source bryozoans are found. From intertidal to subtidal depths of at least 20 m.
All species of Janolus live and feed on erect bryozoans. Pigments from their food source are stored within their cerata enabling them to blend with their host food source, making them difficult to find. Some species grow to 40 mm. The undescribed species shown here around 30 mm.
Robert Burn, 2015. Museum Victoria Field Guides: Nudibranchs and related molluscs. Museum Victoria, Melbourne. pp.7,200.
Australian Museum, Sea Slug Forum. http://www.seaslugforum.net/showall/janosp1. Accessed 24/01/2019.