Tripneutes Gratilla - Hairy Pincushion Urchin

The Hairy Pincushion Urchin is also known as the Sea Egg, and the Priest-hat 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. These urchins work wonders in aquariums that suffer from filamentous algae infestation, consuming this undesirable algae quickly.

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.. 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.

It is extremely difficult to breed in an aquarium with no distinguishing characteristics to help differentiate it from its mate.

If there is insufficient algae for it to graze on, the Hairy Pincushion Urchin should be fed dried seaweed.