The article studies the role of contractile vacuoles in the osmoregulation process of the marine parasitic amoeba, Neoparamoeba perurans. It informs that CVs are reported to occur in single-celled freshwater protozoans, such as ciliates, flagellates and amoebae and it have been reported in marine ciliates. It further mentions that Amoebic gill disease (AGD) is caused by the amphizoic amoebae Neoparamoeba perurans.