Marine Animal Encyclopedia
Long-spined Sea Urchin Diadema savignyi
Many divers on coral reefs have learned to avoid these sea urchins. They bristle with long, sharp spines that can easily wound, even through a wetsuit. The spines are mildly venomous and so brittle that they may break off in the wound. If a diver or predator comes near it, this sea urchin waves its spines vigorously. Only a few tough fish, such as the titan triggerfish, can successfully attack and eat such prickly prey. This species often has striped spines, while the other common Indo-Pacific long-spined species, Diadema setosum, has black spines.