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How do echinoderms use tube feet for movement and feeding?

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Group of fallow deer (Dama dama) stags with large, palmate antlers standing alert in a green summer field. — Animal The fallow deer (*Dama dama*) has been introduced in many areas ever since the Neolithic Period.

Echinoderms utilize a specialized water-vascular system to operate their tube feet, which are essential for both movement and feeding.

Movement

The system functions as a hydraulic network. Fluid is taken in through a madreporite and distributed through radial canals to the tube feet. Each tube foot is connected to a muscular sac called an ampulla. When the ampulla contracts, it forces fluid into the tube foot, causing it to extend. Adhesion to surfaces is achieved through a combination of suction and the secretion of adhesive mucus. Movement occurs as the tube feet extend, attach to a substrate, and then contract via longitudinal muscles to pull the animal forward.123

Feeding

Tube feet are highly adapted for various feeding strategies:
* Capture: In crinoids, tube feet secrete sticky mucus to trap small organisms. Holothurians (sea cucumbers) use modified, tentacle-like tube feet to capture plankton or scoop up sediment.1
* Manipulation: Ophiuroids use their tube feet to hold surfaces and pass food toward their mouths.1
* Force: Asteroids (starfish) use their suckered tube feet to exert continuous pressure on the valves of shellfish, eventually tiring the prey's muscles to open the shell and insert their stomach.1