<P> Tube feet are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers . They are part of the water vascular system . </P> <P> Tube feet function in locomotion, feeding, and respiration . The tube feet in a starfish are arranged in grooves along the arms . They operate through hydraulic pressure . They are used to pass food to the oral mouth at the center, and can attach to surfaces . A starfish that is overturned simply turns one arm over and attaches it to a solid surface, and levers itself the right way up . Tube feet allow these different types of animals to stick to the ocean floor and move slowly . Tube feet consist of two parts: ampullae and podia . Ampullae contain both circular muscles and longitudinal muscle, whereas the podia contain the latter only . The podia use suction to attach to the substratum . </P>

How do tube feet serve in food taking
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