Seasonal Influence on the Parasite Fauna of a Wild Population ofAstronotus ocellatus(Perciformes: Cichlidae) from the Brazilian Amazon

Abstract

Parasite infracommunities were studied in 202 specimens of Astronotus ocellatus collected from a freshwater lake in the State of Amapá, northern Brazil. Relationships between some host attributes (i.e., ontogeny, sex, and body size) and parasite infections were analyzed, but the primary focus was the seasonal variation in the parasite fauna. In total, 6,308,912 parasites belonging to 11 different taxa were found. Protozoa were the most abundant and dominant taxa, but monogeneans, trematode metacercariae, and nematode larvae were also prevalent and abundant. Fish ontogeny had a weak influence on parasite infection rates; juveniles were more parasitized by Dolops nana and Posthodiplostomum sp. The abundances of all parasite species were weakly correlated with host body size (low r(2) values), except D. nana, Contracaecum sp., and Posthodiplostomum sp., which exhibited no correlation between abundance and host body size. Prevalence and abundance were different between flood and drainage seasons for all parasite species, except for D. nana and the 2 metacercarial species. Astronotus ocellatus may represent a link in food-web transmissions for parasites because it is used both as definitive and intermediate host. The parasite fauna of A. ocellatus was composed primarily of ectoparasites, and this could be considered typical of fishes that inhabit lentic waters. Seasonality was a strong determinant in the parasite community structure.

Metazoan parasite communities of Leporinus macrocephalus (Characiformes: Anostomidae) in cultivation systems in the western Amazon, Brazil

“…Although G. leporini in this study had the highest mean intensity of Metazoan parasite communities of Leporinus macrocephalus (Characiformes: Anostomidae) in cultivation systems in the western Amazon, Brazil ACTA AMAZONICA infection in both systems (10.1), they had low prevalence (21.5%), while in southeastern Brazil prevalence was higher (65%), with lower mean infection intensity (4.1) (Martins and Yoshitoshi 2003). The aggregated dispersion of metazoan parasites in L. macrocephalus found in our study is a common pattern in parasite communities of freshwater fish in different regions of Brazil (Machado et al 1996;Abdallah et al 2004;Moreira et al 2005;Paraguassú and Luque 2007;Guidelli et al 2009;Neves et al 2013;Tavares-Dias et al 2013). This mode of dispersion has been associated with the direct life cycle of Monogenoidea parasites, as well as the susceptibility and capacity of immunological response of the hosts (Paraguassú and Luque 2007;Tavares-Dias et al 2013).…”

Are similar the parasite communities structure ofTrachelyopterus coriaceus and Trachelyopterus galeatus (Siluriformes: Auchenipteridae) in the Amazon basin?

“…It is well known that the diet of the fish can be deduced from trophically transmitted parasites and because most endoparasites are associated with a specific ecological niche and diet, high diversity in host parasite fauna is often a result of a diverse host diet. Hence, a diverse parasitic communities of trophically transmitted parasites may indicate that the host population consumed a diversity of prey in habitat (WILSON & HUBSCHMAN, 1985;MORAVEC, 2007;TARASCHEWSKI, 2008;MOREIRA et al, 2009;MORAVEC, 2009;NEVES et al, 2013;TAVARES-DIAS et al, 2013;BITTENCOURT et al, 2014b;TAVARES-DIAS et al, 2014).…”

“…In populations of wild fish, ectoparasites and endoparasites of different taxonomic groups can generally be found (LUNASCHI, 1989;TAKEMOTO & LIZAMA, 2009;KOHN et al, 2011;MESQUITA et al, 2011;NEVES et al, 2013;TAVARES-DIAS et al, 2013). The possibility of obtaining numerous repeats and quantifying the entirety of the parasite population distributed in different infection sites in fish facilitates detection of patterns within population dynamics, interspecies relationships and feeding relationships.…”

“…These may reveal the potential that fish could have for participating as intermediate, paratenic or definitive hosts in the ecological systems of endohelminths (TAKEMOTO & LIZAMA, 2009;MESQUITA et al, 2011;TAVARES-DIAS et al, 2013). However, the parasite community structure may be influenced by the environmental and a variety of other factors that relate mainly to the ecology and physiology of the host, seasonality, habitat quality and presence of larval stages of parasites in invertebrate transmitters (TAKEMOTO & LIZAMA, 2009;KOHN et al, 2011;NEVES et al, 2013;TAVARES-DIAS et al, 2013).…”

Ecology and seasonal variation of parasites in wild Aequidens tetramerus, a Cichlidae from the Amazon

“…This cycle also affects the feeding behavior of hosts (ViolanteGonzález et al 2008) by modifying its exposure to certain parasite species, and it may lead to changes in the community structure of parasites from the host fish. Few investigations have evaluated the effects of seasonality on parasite communities of fish species from Amazon lakes (Vital et al 2011, Neves et al 2013; however, no study investigated the tides influence in the estuarine region of the Amazon River system. In the eastern Amazon (Northern Brazil), the tributaries of Amazon River have strong influence of tides of this river.…”