Water vascular system
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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. (Solomon, 2002). Composed of water filled tube feet and ampulla, Echinoderms move by contracting the muscles around the ampulla forcing water in the tube feet, which causes the foot to extend propelling the animal forward (Solomon, 2002).
Water enters the madreporite and flows through the stone canal and then enters the circular ring canal. Water then is separated into five radial canals that branch into double rows of bulblike structures called ampullae, which are on each side of the ambulacral ridge. The ampullea are connected to sucker like tube feet. Contraction of the ampullae causes the tube feet to stretch as water is brought into them. This whole process allows for movement, and is quite powerful but extremely slow (Gilbertson, 1999).
Sources
- Eldra Solomon, Linda Berg, Diana Martin. 2002. Biology. Brooks/Cole
- Gilbertson, Lance; Zoology Lab Manuel; McGraw Hill Companies, New York; ISBN 0-07- 237716-X(fourth edition, 1999)de:Ambulacralsystem