title: Patterns of host specificity among the helminth parasite fauna of freshwater siluriforms: testing the biogeographical core parasite fauna hypothesis.
abstract: Host specificity plays an essential role in shaping the evolutionary history of host-parasite associations. In this study, an index of host specificity recently proposed was used to test, quantitatively, the hypothesis that some groups of parasites are characteristics of some host fish families along their distribution range. A database with all published records on the helminth parasites of freshwater siluriforms of Mexico was used. The host specificity index was used considering its advantage to measure the taxonomic heterogeneity of the host assemblages and its appropriateness for unequal sampling data. The helminth parasite fauna of freshwater siluriforms in Mexico seems to be specific for different host taxonomic categories. However, a relatively high number of species (47% of the total helminth fauna) is specific to their respective host family. This result provides further corroboration for the biogeographic hypothesis of the core helminth fauna proposed previously. The statistical values for host specificity obtained herein seem to be independent of host range. However, the accurate taxonomic identification of the parasites is fundamental for the evaluation of host specificity and the accurate evolutionary interpretation of this phenomenon.
authors.affiliation: Museo de Zoología "Alfonso L. Herrera", Departamento de Biología Evolutiva, Facultad de Ciencias, Universidad Nacional Autónoma de México, Apartado Postal 70-399, 04510 México, D.F., México. rogrosas@ciencias.unam.mx
authors.forename: Rogelio
authors.initials: R
authors.lastname: Rosas-Valdez
authors.forename: Gerardo Pérez-Ponce
authors.initials: GP
authors.lastname: de León
mesh_terms: D000818:Animals; D002397:Catfishes / Q000469:parasitology*; D005393:Fish Diseases / Q000469:parasitology*; D005618:Fresh Water; D006374:Helminthiasis, Animal / Q000469:parasitology*; D006376:Helminths / Q000145:classification / Q000502:physiology*; D006790:Host-Parasite Interactions; D008800:Mexico; D013045:Species Specificity