Body Support hydrostatic support by water vascular system . Sensory organs are few and primitive. Simple visual, touch, and chemoreceptive senses. Pedicellariae on the integument keep the body surface clean of encrusting organisms and function in food gathering. Tube feet are controlled by hydrostatic pressure in water vascular system and allow creeping and slow predation.
Crinoids are sessile.
Water enters through the madreporite and travels through the stone canal, to the ring canal, and thence to the radial canals. Technically complete with mouth and anus, but anus is fairly non-functional. Some can evert their stomach and digest the prey external to their body. Reproduction asexual reproduction is rare. Some are predatory and can split open large clamshells.