Trophic Relations of Protozoa

Abstract

Free-living Protozoa occupy a range of trophic levels. Those which feed on algae, both the unicellular and filamentous varieties, are primary consumers in the herbivore food chain dependent on fresh autotrophic organic matter. Other protozoans exploit bacteria as a food source and as microbivores perform a role in the food chain based on dead organic matter. Both these trophic groups of Protozoa, and other small elements in the micro- and meiofauna, are exploited by predacious protozoan species. The Protozoa form an element in the larger micro- and meiofaunal communities of soils and aquatic environments, but on a smaller scale the various protozoan groups themselves constitute a community with a defined trophic hierarchy (Figure 5.1).