Ciliates as bioindicators of water quality: A case study in the neotropical region and evidence of phylogenetic signals (18S-rDNA).

The aim of our study was to evaluate the water quality of an urban stream in southeastern Brazil by analyzing epibenthic ciliates, and to investigate the existence of phylogenetic signal for saprobity in ciliates. However, before conducting this type of phylogenetic study, it is necessary to evaluate if the saprobic classification used frequently in the northern Hemisphere is suitable for neotropical ecosystems. Sediment samples were collected from five sampling stations: two in rural areas and three in urban areas.