Water vascular system is characteristic of
Protozoa
Porifera
Annelida
Echinodermata
D.
Echinodermata
Ambulacral system or water vascular system is a characteristic feature of echinoderms. This system comprises the system of canals and tube feet. Tube feet are also a characteristic feature of echinoderms, which help in adhesion, respiration, food capturing and locomotion.