Longitudinal change in prevalence of infestation on ciliated epibiont protozoans upon oligochaete along the Paraibuna river, Juiz de Fora city, Minas Gerais, Brazil

Abstract

Aiming to record and analyze the prevalence of infestation by ciliated protozoa peritrichs colonizing oligochaetes along the Paraibuna River, Juiz de Fora City, Minas Gerais, a sampling of sediment was performed at different sampling stations along the Paraibuna River. The oligochaetes were screened from the fixed samples, and then examined through light microscopy, to quantify the prevalence of infestation of epibiont ciliates. Several physicochemical parameters of water were analized in all sampling sites. Rhabdostyla sp. was found only in three of the five collecting points and greater abundance of oligochaetes in some sites may be related to the preference of both peritrichs ciliates and oligochaetes for eutrophic environments, due to the fact that these points were already located in urbanized locations. The occurrence and the prevalence of epibiont pertrichs have been identified as an important tool for evaluanting water quality in lotic systems. The data suggest a direct relation between prevalence of infestation and organic pollution, that can be a direct contributor to the spread of several diseases among people who may have contact with the water of this environment.