Echinoderms Section Echinoderms Section ReviewReview

What characteristics do What characteristics do echinoderms have?echinoderms have?

• They are invertebrates that have an They are invertebrates that have an internal skeleton and a water internal skeleton and a water vascular system.vascular system.

How does an echinoderm use How does an echinoderm use its tube feet to grip a surface?its tube feet to grip a surface?

• The tube feet are sticky at the ends The tube feet are sticky at the ends and when filled with water, they at as and when filled with water, they at as suction cups. suction cups.

Why is movement using tube Why is movement using tube feet slow?feet slow?

• Because since the tube feet act as Because since the tube feet act as suctions, the animal must release the suctions, the animal must release the suction each time it moves and put suction each time it moves and put the suction tube feet down again, then the suction tube feet down again, then repeat this same action to get to its repeat this same action to get to its destination. destination.

What are the four major groups What are the four major groups of echinoderms?of echinoderms?

• Sea starsSea stars

• Brittle starsBrittle stars

• Sea urchinsSea urchins

• Sea cucumbersSea cucumbers