- Echinoderms include sea stars, sea urchins, feather stars, brittle stars and sea cucumbers;
- All are found in a diverse range of marine habitats from intertidal surf beaches to the deepest oceans;
- Sydney is home to approx. 120 species of echinoderms;
- Some echinoderms have excellent powers of regeneration;
- Sea stars often regrow arms bitten off by predators and, if disturbed, brittle stars drop off an arm or part of an arm. This allows them to escape predators as the cast-off arm continues to wriggle to distract the attention of the attacker; and
- Common features of all echinoderms include an internal calcareous skeleton and a water vascular system that operates their tube feet.