The Priest-hat Urchin is also known as the Sea Egg, and the Hairy Pincushion Urchin. It has five or ten double rows of white and red spines separated by spaces of red, purple, white or black. To camouflage itself, it often covers itself with rocks, sponges, shells, or algae. In addition to camouflage, this provides shade, and in some cases, a food source.
It will generally do well in an aquarium if provided with ample hiding places and a large area in which to move. It prefers an aquarium with live rock so that it can graze on algae and it will even eat Caulerpa sp.. Care must be taken when placing it in a reef tank, as it will eat some corals. It should be housed with nonaggressive fish. It is sensitive to high levels of copper-based medications. Poor water conditions will cause it to shed its spines and rapidly decline in health.
If there is insufficient algae for it to graze on, the Priest-hat Urchin should be fed dried seaweed.