Parasites perform important roles in the ecosystems they occupy, which contribute to the diversification and structuring of communities formed by their hosts. As a result of this importance, understanding the process of historical association between parasites and their hosts is fundamental, as this understanding is the basis for monitoring changes in the standards of parasitic associations, especially those resulting from environmental disturbances, which allows for epizootic outbreaks to occur and cause damage to natural ecosystems. However, monitoring at this level requires that integrative taxonomy studies (i.e. using basic and advanced morphological analysis, phylogenic, biogeography, ecology, among others) be performed. The study model of the present proposal focuses on the integrative taxonomy of the monogeneans platelminths. These parasites occur worldwide, with some lineages restricted to South America, are endowed with modified structures for parasitic lifestyle (e.g. hooks, anchors, bars, staples) and may eventually cause disease and lead their hosts to death. The goal is to highlight an unknown fauna of these monogeneans, but moreover, understanding the relationships of historical associations that led to the current standard of distribution of these organisms in the ecosystem formed by the Rio Pardo, Middle Paranapanema. The material to be studied is being collected in a project approved by FAPESP (2020/05412-9) and the laboratory in which this study will be developed has all the infrastructure and resources necessary for the development of this project.