Diversidade de helmintos parasitas das espécies Serrasalmus maculatus Kner, 1858 e Serrasalmus marginatus Valenciennes, 1837 do Refúgio Biológico de Santa Helena, PR

Abstract

The taxonomic knowledge of the diversity of parasites is of great relevance for any study of ecological and evolutionary order, as parasitism plays an important role in ecosystems, regulating the abundance or density of host populations, establishing food chains and structuring animal communities. Over the years, several authors have advanced in research and in estimates of parasitic biodiversity, as it is known that parasites are responsible for one third of the species of organisms on planet Earth. Serrasalmids are voracious predators, popularly known as piranhas. With the formation of the Itaipu reservoir and the consequent removal of the geographic barrier constituted by the Salto de Sete Quedas (Guaíra - PR), the ascension of Serrasalmus marginatus Valenciennes, 1837 occurred, which, over time, dominated the congeneric Serrasalmus maculatus Kner, 1858. The objective of this work was to expand and compare the parasitological knowledge of the aforementioned species collected in the surroundings of the Santa Helena Biological Refuge-PR and in the lower São Francisco Falso River, southern arm, considered in this study as an area of influence of the Conservation Unit.Fish were collected with gill nets,quarterly, from 2018 to 2019. It was possible to record ten taxa of parasites, in which Spinoxiurys and Raphidascaris are new records for the host species. The results showed that the most abundant parasite species in both hosts and sampling areas were: Austrodiplostomum compactum (Lutz, 1928) (Digenea, Diplostomidae), Rhinoxenus sp. (Monogenea) and Spinoxyuris sp. (Nematoda). This study expands the parasitological knowledge and contributes with parasitological information from the neotropical and Western Paraná region.