Question

The water vascular system of echinoderms helps in:

Answer 1

The water vascular system is a hydraulic system used by echinoderms, such as sea stars and sea urchins, for locomotion, food and waste transportation, and respiration. The system is composed of canals connecting numerous tube feet.

Answer 2

$\text{\underline{\underline{Structure\:of\:water\:vascular\:system:}}}$


⚫The water-vascular system consists of a performed plate called madreporite the pores of which allow the sea water to enter into the system.


⚫From the madreporite starts stone canal which opens into the ring canal.


⚫From each angle of ring canal arises radial canal which runs through the length of each arm.


⚫From radial canal arise lateral canals which end in tube feet. The tube feet are the tube-like appendages. There are two double rows of tube feet in each arm, one double row in relation to each series alternatively placed long and short lateral canals.


⚫Each tube foot can be distinguished into three regions:

(i) A round sac-like ampulla.

(ii) A middle tubular podium.

(iii) A cup-like sucke* at the lower end of podium.


$\text{\underline{Example:}}$ Starfish