title: The European eel--the swim bladder-nematode system provides a new view of the invasion paradox.
abstract: It is widely assumed that the likelihood of invasion decreases with increased species richness in the recipient community. However, the invasion paradox supports a negative and a positive relationship between native biodiversity and the success of an invader. Here, we show that for a host-parasite system (Anguilla anguilla as host and Anguillicoloides crassus as parasitic invader), invasion increases with native micro- and macroparasitic species richness. In fact, about 30% of the A. crassus intensity in eels could be explained by the number of both micro- and macroparasite species. This pattern could be due to the fact that A. crassus exploits a niche (the swim bladder) that is unoccupied by native parasite species and by the Th1/Th2 trade-off between native microparasites and the invader. We conclude that the host-parasite system resistance to invasion may depend on both niche availability and the Th1/Th2 trade-off. As well, we encourage researchers to incorporate native parasite richness as a risk factor in epidemiological models of A. crassus.
authors.affiliation: Departamento de Sanidad Animal, Facultad de Veterinaria, Universidad de Murcia, E-30100, Murcia, Spain.
authors.forename: Carlos
authors.initials: C
authors.lastname: Martínez-Carrasco
authors.forename: Emmanuel
authors.initials: E
authors.lastname: Serrano
authors.forename: Rocio Ruiz
authors.initials: RR
authors.lastname: de Ybáñez
authors.forename: José
authors.initials: J
authors.lastname: Peñalver
authors.forename: José Antonio
authors.initials: JA
authors.lastname: García
authors.forename: Alfonsa
authors.initials: A
authors.lastname: García-Ayala
authors.forename: Sergé
authors.initials: S
authors.lastname: Morand
authors.forename: Pilar
authors.initials: P
authors.lastname: Muñoz
mesh_terms: D000400:Air Sacs / Q000276:immunology / Q000469:parasitology*; D000811:Anguilla / Q000276:immunology / Q000469:parasitology*; D000818:Animals; D044822:Biodiversity; D005393:Fish Diseases / Q000276:immunology / Q000469:parasitology*; D006790:Host-Parasite Interactions; D009348:Nematoda / Q000276:immunology; D009349:Nematode Infections / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology