Common Name: Purple Urchin
Distribution: Uncommon in the Solitary Islands Marine Park. Distributed throughout the Eastern Indian Ocean and Australia. In Australia recorded from around Ningaloo in Western Australia, across the south of the continent north to Caloundra in southern Queensland, including around Tasmania.
Ecological Notes: Frequents sheltered and moderately exposed reef, depth from intertidal to 35 m.
Additional Notes: Variable in colour, from purple through green and white, often different between spines and test. Spines on animals on the west coast of Australia tend to be shorter. More common in the southern part of its range, it is the most common sea urchin in southern Australia and supports an extensive commercial fishery. Aggregations can remove larger macro algae causing extensive overgrazing and urchin barrens on the reef. Underside shown in lower photograph. Test diameter to 90 mm, spines to 30 mm.
References: Graham J. Edgar. Australian Marine Life, 2nd Edition, 2008. Reed New Holland Publishers. pp.419-20.
Palomares, M.L.D. and D. Pauly. Editors. 2018. SeaLifeBase. World Wide Web electronic publication.
https://www.sealifebase.ca/summary/Heliocidaris-erythrogramma.html. Accessed 09/03/2019.