Primovula rosewateri (Cate, 1973)

Distribution: 

Common in the Solitary Islands Marine Park. Distributed throughout the West-Pacific region, from Indonesia and the Philippines, to Japan and Australia. The family is recorded in Australia from around Exmouth in Western Australia, across the tropical north, the Great Barrier Reef in Queensland south to around Port Stephens in New South Wales.

Ecological Notes: 

Frequents host gorgonian branches, upon which it feeds and lays eggs.

Additional Notes: 

Mantle is white with large red spots, short yellow filaments with white tips. Well camouflaged on its host, often the first hint of its presence is the sighting of egg masses towards the ends of the gorgonian branches. Grows to 15 mm. Formerly known as Crenavolva rosewateri.

References: 

Reef Creature Identification, Tropical Pacific. Paul Humann, Ned DeLoach, New World Publications Inc, Jacksonville, Florida, USA, 2012 edition. p.266.