Water Vascular System

Real World Example

Imagine trying to inflate a long, bendy balloon to make a balloon animal. Just as the air flows through the balloon to give it shape and movement, the water vascular system in echinoderms like starfish uses fluid-filled tubes to control their movements and maintain their structure. Just as the air pressure in different parts of the balloon allows you to twist and shape it, the water pressure in the tubes of the starfish allows it to extend and contract its tube feet for locomotion and feeding.