The Seasonal Succession of Biotic Communities in Wetlands of the Tropical Wet‐and‐Dry Climatic Zone: IV. The Free‐Living Sarcodines and Ciliates of the Pantanal of Mato Grosso, Brazil

Abstract

Abstract This fourth paper in a series on the effects of the wet‐and‐dry climate on the northern Pantanal, Mato Grosso, Brazil, provides an outline of the seasonal activity of sarcodine and ciliate species. Both of these groups of protozoans include grazers on bacteria and algae, predators, and omnivores. Apparently because of their more complex trophic relationships and competition from small metazoans, the fauna of these groups in the Pantanal is considerably less rich in species than the alga flora, and the populations of most species remain small throughout the year. The presence of only 97 species was recorded during a period of study lasting about three and a half years. While the number of testacean species encountered is not notably less than expected, the number and diversity of the ciliate fauna are remarkably low compared to those encountered not only in the eutrophic waters of the temperate zones but also in water bodies in the eastern part of Brazil. The species found are almost exclusively cosmopolitan or circumtropical in distribution.