title: Drivers of parasite sharing among Neotropical freshwater fishes.
abstract: Because host-parasite interactions are so ubiquitous, it is of primary interest for ecologists to understand the factors that generate, maintain and constrain these associations. Phylogenetic comparative studies have found abundant evidence for host-switching to relatively unrelated hosts, sometimes related to diversification events, in a variety of host-parasite systems. For Monogenoidea (Platyhelminthes) parasites, it has been suggested that the co-speciation model alone cannot explain host occurrences, hence host-switching and/or non-vicariant modes of speciation should be associated with the origins and diversification of several monogenoid taxa. The factors that shape broad patterns of parasite sharing were investigated using path analysis as a way to generate hypotheses about the origins of host-parasite interactions between monogenoid gill parasites and Neotropical freshwater fishes. Parasite sharing was assessed from an interaction matrix, and explanatory variables included phylogenetic relationships, environmental preferences, biological traits and geographic distribution for each host species. Although geographic distribution of hosts and host ecology are important factors to understand host-parasite interactions, especially within host lineages that share a relatively recent evolutionary history, phylogeny had the strongest overall direct effect on parasite sharing. Phylogenetic contiguity of host communities may allow a 'stepping-stone' mode of host-switching, which increases parasite sharing. Our results reinforce the importance of including evolutionary history in the study of ecological associations, including emerging infectious diseases risk assessment.
authors.affiliation: Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Departamento de Zoologia, Universidade Federal do Paraná, Setor de Ciências Biológicas, Caixa Postal 19073, CEP 81531-980, Curitiba, PR, Brazil.
authors.forename: Mariana P
authors.identifier: http://orcid.org/0000-0002-1253-2536
authors.initials: MP
authors.lastname: Braga
authors.affiliation: Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Departamento de Zoologia, Universidade Federal do Paraná, Setor de Ciências Biológicas, Caixa Postal 19073, CEP 81531-980, Curitiba, PR, Brazil.
authors.forename: Emanuel
authors.initials: E
authors.lastname: Razzolini
authors.affiliation: Laboratório de Ecologia Molecular e Parasitologia Evolutiva, Departamento de Zoologia, Universidade Federal do Paraná, Setor de Ciências Biológicas, Caixa Postal 19073, CEP 81531-980, Curitiba, PR, Brazil.
authors.forename: Walter A
authors.initials: WA
authors.lastname: Boeger
mesh_terms: D000818:Animals; D017753:Ecosystem; D005393:Fish Diseases / Q000453:epidemiology / Q000469:parasitology*; D005843:Geography; D005880:Gills / Q000469:parasitology; D010802:Phylogeny; D045483:Rivers; D014200:Trematoda / Q000502:physiology*; D014201:Trematode Infections / Q000453:epidemiology
keywords: Monogenoidea; antagonistic interactions; ecological fitting; ecological networks; host‐switching; partial least squares path modelling; stepping‐stones