Rock Platforms: Subtidal Zone - Sea Urchins
Echinoderms, such as sea urchins, are grazers. The mouth faces downwards and is surrounded by hard, calcareous plates.
Algae are scraped off the rocks as the sea urchin moves across the substrate.
Sea urchins are sometimes found in rock pools but - unlike their relatives, the starfish - rarely venture into the intertidal zone.
Move the mouse over the image to explore the rock pool.
Sea cucumber
Sea urchin
Sponge
Sea star
Fish