Long black needles mark the entrance to a reef crevice. By day, this urchin shelters among the rocks; after dark, it comes out to feed.
- Local names
- Vana
- Habitat
- Lagoon and reef
About this species
Diadema savignyi has a rigid calcareous shell, called a test, pierced by openings and covered in long spines. Its jaw has five strong teeth; this feeding apparatus is known as Aristotle’s lantern.
The guide describes it in rocky habitats and mixed sand-and-coral areas, including turbid water. It hides from predators in reef cavities during daylight and forages over coral heads and nearby sand at night.