title: Nonmanipulative parasites in manipulated hosts: 'hitch-hikers' or simply 'lucky passengers'?
abstract: Manipulation of intermediate host behavior to favor parasitic transmission has been demonstrated in a wide of range of parasitic taxa. Recent advances in parasitology have suggested that nonmanipulative parasite species can obtain a high probability of transmission simply by infecting hosts already manipulated ('hitch-hiker' parasites). In this study, from a field collection of Gammarus aequicauda (Amphipoda, second intermediate host), we analyzed the ecological association between the manipulative trematode Microphallus papillorobustus and the 2 nonmanipulative trematodes Microphallus hoffmanni and Levinseniella tridigitata. Although these 2 nonmanipulative parasites should be a priori advantaged when infecting manipulated gammarids, there was no significant ecological association between parasite species. We discuss the possible reasons why these 2 nonmanipulative parasites are only 'lucky passengers' rather than 'hitch-hikers.'
authors.affiliation: Department of Zoology, University of Otago, Dunedin, New Zealand.
authors.forename: F
authors.initials: F
authors.lastname: Thomas
authors.forename: R
authors.initials: R
authors.lastname: Poulin
authors.forename: F
authors.initials: F
authors.lastname: Renaud
mesh_terms: D000818:Animals; D003445:Crustacea / Q000469:parasitology*; D005260:Female; D006790:Host-Parasite Interactions; D008297:Male; D014200:Trematoda / Q000502:physiology*