Parasites community of Astronotus crassipinnis (Cichlidae), a fish from the Brazilian Amazon

We provide the first study on the diversity and community of parasites in Astronotus crassipinnis from the lower Amazon River, in Brazil. Of 35 hosts examined, 100% were infected with one or more species of parasites, such as Gussevia asota, Gussevia astronoti, Gussevia rogersi, Posthodiplostomum sp., Contracaecum sp., Gorytocephalus sp. and Dolops longicauda. Gussevia asota, G. astronoti and G. rogersi were dominant, and, in total, 9788 parasites were collected. The richness of parasite species (4.9±0.7), Brillouin diversity (0.46±0.28) and evenness (0.29±0.17) were low. Parasites had aggregated dispersion, parasitism did not affect the host condition factor, and host size did not influence abundance, species richness and parasite diversity. The parasitic fauna was characterized by the presence of few species of parasites with high prevalence and low abundance, specifically the endoparasites, besides dominance of ectoparasites. The presence of endoparasites indicates that the diet of A. crassipinnis consists mostly of mollusks and microcrustaceans. This fish species is an intermediate host for Posthodiplostomum sp., Contracaecum sp. and Gorytocephalus sp., parasites found in larval stage. Finally, the behavior and availability of infective stages, which are intermediate hosts for endoparasites, were factors structuring the communities of endoparasites.