Metazoan endoparasites of <i>Brycon orbignyanus</i> (Characidae: Bryconinae) in a neotropical floodplain

Abstract

Species richness and composition are central themes in community ecology of helminths because they improve the understanding of factors that determine community structure. Floodplain ecosystems and the environmental alterations induced by hydrological cycles are factors that maintain biodiversity over time, as observed in the Upper Paraná River floodplain, where the individuals of Brycon orbignyanus were collected. The objective of this study was to evaluate whether variables such as the richness and abundance of endoparasites are related to the fish size during different hydrological periods (high and low waters). A total of 163 endoparasites belonging to 13 species were collected in the 104 fish examined. Fish size had a positive correlation with mean diversity and abundance of the endoparasite infracommunity, supporting the idea that larger hosts are able to harbor a more abundant and diverse parasite infracommunity. The diversity of habitats provided by the floodplain can be considered the main factor explaining the differences between these attributes of parasite species. Variations in parasite richness between different hosts provide not only a good model for studies on community diversification but are also of great interest in species conservation. All parasite species found in B. orbignyanus were recorded for the first time in this host, especially in the Upper Paraná River floodplain.

Helminth endoparasites of endemic fish Pygocentrus piraya (Characiformes, Serrasalmidae) from Três Marias reservoir, Minas Gerais, Brazil

“…Austrodiplostomum sp., P. (S.) inopinatus and Contracaecum sp. were the common species shared by both endoparasitic fauna; they are generalist species that often parasitize several fish species belonging to different orders in different regions (São-Sabas & Brasil-Sato 2014, Santos-Clapp & Brasil-Sato 2014, Monteiro et al 2016, Ribeiro et al 2016, Almeida-Berto et al 2018, Fujimoto et al 2018, Fernandes et al 2019. Representatives of Acanthocephala and Pentastomida were not found in the endoparasitic fauna observed in P. piraya fish living in upper São Francisco river.…”