What adaptations have echinoderms developed to survive?

One Adaptation of an Echinoderm

Echinoderm-ἐχινοδέρματα. One adaptation of the echinoderm is that they have spikes and toxins to keep away predators. Echinoderms include: starfish, sea urchins, sand dollars, sea cucumber, feather lilies, and many others. in fact about 5000 known

-Kate Ash