Brown Rock Urchin
Arbacia punctulata ON EXHIBIT:
Seahorses: Beyond Imagination Exhibit at River Journey
When these urchins are not eating they hide under shells or burrow into the sand or rocks. The name sea urchin comes from the Old English name for spiny hedgehog. An urchin’s mouth is underneath the animal because it is constantly grazing as it moves. The anus is on top of the body between the spines and waste is sometimes excreted as a form of defense. Scientists use larval sea urchins to study embyology and development.