Temporal structure of the peritrich ciliate assemblage in a large Neotropical lake

Abstract

Background: Periphytic communities are usually composed by prokaryoticand eukaryotic microbes and small metazoans and could be found in anysubmerged surface in aquatic environments. Ciliates generally are thedominant organisms in periphytic communities where they can formassemblages of complex taxonomic composition. Among these ciliate taxa,peritrichs are very common organisms found in periphyton; also, they areeasy to collect, be easily recognized, and have been widely used toevaluate and monitor ecological and ecotoxicological investigations.Several studies have been focused on periphytic communities infreshwaters from the Northern Hemisphere, with very little data onsimilar environments in the South. In the present study, we analyzed thestructure and temporal dynamics of the ciliate peritrich community in aNeotropical shallow lake, comparing the fluctuation of the peritrichcommunity with environmental factors.Results: Peritrichia comprised a total of 22 morphospecies throughoutthe year with genera Epistylis and Vorticella the most diverse andabundant genera. Peritrich density was considerably higher during falland winter, demonstrating a clear seasonal cycle. Small, solitaryspecies showed no pattern of dominance during any particular stage ofsuccession, reaching abundance peak any time during the sampling period.On the other hand, large colonial species were abundant only in the lasthalf of each successional cycle. Species abundance was correlated totemporal and environmental drivers.Conclusion: Our results support the hypothesis of a temporal pattern ofsuccession in the community of peritrich ciliates that composes theperiphyton of the studied lake with different responses by individualspecies to successional time, year, season, and environmental factors.