What is the function of the water vascular system in echinoderms?
The water vascular system performs many important functions in echinoderms, including locomotion, respiration, and feeding; in addition, most sensory neurons are located at the termini of podia (tubefeet) which are part of this organ system. The water vascular system may have evolved from simple tentacular systems similar to those in other deuterostome phyla, such as the tentacles of pterobranch hemichordates. However, there are many derived features of the water vascular system in echinoderms, including: an embryological origin from left mesocoel, podia arranged along branches (ambulacra), and a central circumesophageal ring.
