Is there any way to differentiate between a contractile and a non contractile vacuole by observation alone in any given organism
Contractile vacoules are usually surrounded by distinguishing structures


  The contractile vacuole has several structures attached to it in most cells, such as membrane folds, tubules, water tracts and small vesicles. These structures have been termed the spongiome; the contractile vacuole together with the spongiome is sometimes called the "contractile vacuole complex (CVC). The spongiome serves several functions in water transport into the contractile vacuole and in localization and docking of the contractile vacuole within the cell.


This type of arrangement is not common in non-contractile vacuoles like gas, sap or food vacuoles.