place where water is taken into water vascular system.
water vascular system
system that pumps water from sieve plate to tube feet. when water is pumped out the tube foot extends.
center of body of sea star where all the rays branch off. has mouth anus, gonopores.
shell (diatoms, urchins, sand dollars)
wrench shaped structure on sea stars and urchins that keep off encrusting organisms.
used in moving, eating and respiration of sea stars. uses hydraulic pressure, on ventral side of star.
mouth of urchins.
Sea stars. eyespots and smell organs on end of arms. eats mostly bivalves, eversible stomach.
Urchins and sand dollars. herbivores, 5 rows of tube feet from mouth to anus. plates fused together, non eversible stomach.
Brittle stars. no suction cups on tube feet, serpentine locomotion. predaory/detritus eaters. arms can break off as defensive mechanism.
Sea cucumbers. biradial symmetry. reduced tube feet. plates reduced to ossicles. eats sediment to gain nutrients. sac body.
Spiny skinned animals. radial sym in adults (division of 5). moves with water vascular system. endoskeleton.