The eco-dynamical relationship has been established between the environmental variables and the distribution of ciliated protozoa in an aquatic ecosystem in Yaounde, Cameroon that is being subjected to anthropogenic pollution. These biological indicators for polysaprobic and mesosaprobic lotic and lentic systems were more exigent for biotopes with a high level of biodegradable organic and mineral content. Ammonia, Dissolved Carbon Dioxide and the presence of water hardness indicators were more determinant in the proliferation of ciliates such as Caenomorpha medusula and Metopus ovatus which are confirmed biological indicators of very high pollution. The quantitative and qualitative dispersion of the infusorian community was more related to the physico-chemical parameters of the medium that have been considered in our investigation. The stalk and the contractile axis in Vorticella impose a structural resistance of varied pollution load. The spinning movement envisaged in Urocentrum turbo contribute in the search for proper habitat, food and also in absconding the prey-predatorrelationship, which is very rampant in streams and rivers. The presence of a food vacuole, a contractile vacuole, a cytopharynx and pellicles can influence the stability of the ciliate population in water, while the cilia play a primordial role in the displacement of these protozoans in their media as they trophically articulate between the micro-zooplankton and the macro-zooplankton.
