Facultad de Biolog a, Universidad Complutense de Madrid, Madrid, Spain Summary. The ciliated protozoa diversity found inside the digestive liquid of pitcher plant S. purpurea is described. The samples examined come from 9 countries belonging to 3 continents. A total of twenty six ciliates species have been identified. These ciliate species are found frequently in a variety of freshwater ecosystems such as holes in trees or pools of water that accumulate in the natural basins formed by the leaf rosettes of bromeliads.
Results confirm the possible ubiquity and cosmopolitan nature of the ciliated protozoa.
Finally, the functional role of ciliates in the pitcher plant is discussed.