Water Vascular System: 

The water vascular system is another identifying feature of echinoderms. It consists of a series of hydraulic radial and lateral channels spread throughout the entire body. The water vascular system provides many internal and external functions; including internal transport and locomotion (Ruppert et al. 2004). Each series of lateral channels that run down each of the arms, terminates at the end of a tube foot or ampulla. The water vascular system is lined with membranous myoepithelium. The myoepithelium is ciliated and muscularised aiding in internal movement of water (Ruppert et al. 2004).	Tube Feet.
Locomotion: Sea Star locomotion is a complicated process that relies on changes in homeostatic pressure throughout the different compartments of the WVS. The extension of a tube foot occurs when there is a contraction of the muscles within the ampulla above the foot. This contraction, forces water into the foot – forcing outwards (Ruppert et al. 2004). Nardoa novaecaledoniae has the ability to contract one side of the arm, forcing the pressure into the other side, and therefore bending the appendage. When the animal is turned upside down, an automatic righting reflex is induced until it has successfully turned over itself over (As seen in the video) (Ruppert et al. 2004).
	Ampullae: sacks of water with the WVS above each tube foot                Tube feet can extent and contract at different times.
This type of controlled movement allows the animal to fit into small unlikely places.  Asteroidea also have mutable connective tissue which aids movement and flexiblity. This process is controlled by the nervous system and allows changes in the mechanical properties of the muscles such as strength, stiffness and viscosity, within a few seconds (Wilkie 2001). Echinoderms have a unique type of mutable connective tissue, made up of thin strands of collagenous tissue (Wilkie 2001).