Beachcombers Field Guide - Department Of Fisheries Western ...

Sea urchin
Echinodermata – Echinoidea
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.