Abstract
Fish are the vertebrates with the highest number of host-parasite associations, both with parasites from different phyla even from different kingdoms. It is estimated that only 6% of Brazilian fish species have been studied regarding their parasitic fauna and, therefore, the biodiversity of fish parasites is still incipient in Brazil. Among the main groups of fish parasites, ergasilids, mixozoans, and monogeneans are those with great potential for describing new species, in addition to being the most impacting parasites from the health point of view, especially considering the frequency of occurrence of this parasite in fish. natives. Thus, we aimed to study, based on morphological and molecular data, the diversity, taxonomy, and systematics of ergasilids, mixozoans and monogenetic parasites of 10 dominant fish species (Astyanax paranae, Astyanax lacustris, Characidium schubarti, Galeocharax gulo, Gymnotus sylvius, Imparfinis mirini, Phalloceros harpagos, Pimelodella avanhandavae, Schizodon nasutus, and Steindachnerina insculpta) collected along the longitudinal gradient (from the source to the mouth) of the Rio Pardo, Middle Paranapanema River, São Paulo. For this study, morphological analyzes will be performed in conjunction with molecular analyzes using ribosomal (SSU rDNA, LSU rDNA, and ITS) and mitochondrial (COI) markers. The results obtained during the realization of the project will be important for the knowledge of Brazilian biodiversity, a better understanding of the structure of parasitic communities, the taxonomy, systematics, and phylogeny of parasites in this still little explored environment in the Middle Paranapanema. (AU)