Sea urchin
Echinodermata – Echinoidea
Distribution:
Known as a sea egg, this hollow-shaped ball is actually the internal skeleton or test of a sea urchin. When alive, the test is covered with spines, which help the urchin to move around, as well as protect it from predators. The spines break off when the urchin dies and the empty tests wash up on the beach.
Did you know?
Sea urchins are grazers, feeding on encrusting organisms such as sponges and algae. Their mouth is in the centre on the underside and contains a set of jaws and horny teeth, named Aristole’s lantern.
In This Section
- Chordates – Animals with backbones
- Invertebrates – Animals without backbones
- Abalone
- Acorn barnacle
- Baler shell
- Blue button sea jelly
- Bluebottle
- Bryozoan
- Bubbler crabs and sand balls
- Chiton
- Cone shell
- Coral
- Cowry shell
- Crab
- Cuttlebone
- Goose barnacle
- Hermit crabs
- Horned ghost crab (Manburr)
- Limpet
- Mud crab
- Mussel
- Periwinkle
- Pipi
- Ram’s horn shell
- Razor clam
- Sand dollars
- Scallop
- Sea hare
- Sea hares
- Sea jelly
- Sea star
- Sea urchin
- Silver-lip pearl oyster
- Sponge
- Tube worm
- Turban snail
- Violet snail
- Marine Pests
- Seagrasses and Algae
- Unusual Finds