What is the system that permits movement and fixation to echinoderms?
The system that permits movement and fixation to substrates in echinoderms is called the ambulacral system. In these animals water enters through a structure called madreporite, passes through channels and reaches the ambulacral feet in the undersurface of the body. In the ambulacral region in contact with the substrate, there are tube feet filled and emptied by water thus acting as suckers.
