Defines echinoderms, such as sand dollars and crown-of-thorns sea stars, and describes their physical characteristics, life cycles, habitats, sense, food, and means of self-defense.

What are echinoderms? -- Echinoderm bodies -- The life cycles of echinoderms -- Where echinoderms live -- How echinoderms sense the world -- What echinoderms eat -- How echinoderms defend themselves -- Up close: sand dollars -- Up close: the crown-of-thorns sea star -- Where can you see echinoderms?.