Ecological aspects of the parasites in Cichlasoma bimaculatum (Cichlidae), ornamental fish from the Brazilian Amazon.

This study investigated the parasitic fauna of Cichlasoma bimaculatum of a tributary from the Amazon River system, northern Brazil. The prevalence of infection was 94.6 % and, in total, 428 267 parasites, such as Ichthyophthirius multifiliis, Piscinoodinium pillulare (Protozoa), Gussevia arilla (Monogenoidea), Posthodiplostomum sp. (Digenea) and Procamallanus (Spirocamallanus) inopinatus (Nematoda) were collected. However, the dominance was mainly of I. multifiliis, while P. (S.) inopinatus was the parasite species with the lower levels of prevalence and abundance of infection. These parasite species showed an aggregated dispersion pattern. The parasitic fauna was characterized by the presence of few species of parasites with high prevalence and abundance, specifically ectoparasites, and a low number of endoparasites. The observed pattern is explained by the mode of life of the host and it is suggested that C. bimaculatum occupies a low trophic level at the food web