Echinoderms are characterised by the

Echinoderms are characterised by the presence of water vascular system which helps in locomotion, capture and transport of food and respiration. They lack an excretory system. They have a complete digestive system with mouth on the lower (ventral) side and anus on the upper (dorsal) side. They have an endoskeleton of calcareous ossicles and spines. They exhibit organ-system level of organisation.