The Pin-cushion Urchin is a tropical species and its population in Sydney fluctuates. In some years it can be abundant while in other years quite rare.
The Pin-cushion Urchin has a brown or purple test (body), short white spines sometimes tipped with orange, and brownish-red tube feet.
Pin-cushion Urchins live in intertidal areas and coastal waters to a depth of 75 m.
The Pin-cushion Urchin is found in Queensland, New South Wales and Western Australia. Also found in the Indo-Pacific region.
Other behaviours and adaptations
This species has a habit of grabbing pieces of seaweed, shell or pebbles with its tube feet and covering itself. This may act as camouflage and protect it from predators and the sun.