Patterns of parasitic infections in fish from a floodplain: use of functional traits and phylogeny from fish and parasites.

Abstract

Functional traits are the measurable properties of organisms that influence their performance through their effects on individual growth, survival, and reproduction. Therefore, the choice of functional characteristics is essential for drawing solid ecological conclusions and predicting ecosystem properties and interactions between organisms. The structure of the parasite community can vary over time and space, resulting from variations in host characteristics, phylogenetic relationships, and environmental characteristics. These can be examined at different levels of diversity: alpha (local diversity) and beta (variation in community composition between locations), including multiple facets such as taxonomic (TD), functional (FD), and phylogenetic (PD). We evaluated which host characteristics may be determinant in the composition of fish parasites from the upper Paraná River floodplain; and compared different facets of endoparasite biodiversity at the sampling unit level (α diversity or parasite diversity at the level of an individual host) and between sampling units (parasite diversity within (β1) or between (β2) host individuals of a species). The host's diet was the factor that had the greatest influence on the composition and similarity of endoparasites in floodplain fish. The α diversity of endoparasite species differed mainly in terms of TD and PPD. Regarding β diversity, the parasite communities presented patterns grouped at different levels (β1 and β2, respectively). To explain patterns in endoparasite diversity, functional traits, and fish phylogeny act as drivers of parasite community structure, with diet being one of the main factors. And the assembly patterns in the endoparasite infracommunities of different floodplain host species reflect the characteristics of their component and composite communities.