title: Non-native species disrupt the worldwide patterns of freshwater fish body size: implications for Bergmann's rule.
abstract: In this study, we test whether established non-native species induce functional changes in natural assemblages. We combined data on the body size of freshwater fish species and a worldwide data set of native and non-native fish species for 1058 river basins. We show that non-native fish species are significantly larger than their native counterparts and are a non-random subset of the worldwide set of fish species. We further show that the median body size of fish assemblages increases in the course of introductions. These changes are the opposite of those expected under several null models. Introductions shift body size patterns related to several abiotic factors (e.g. glacier coverage and temperature) in a way that modifies latitudinal patterns (i.e. Bergmann's rule), especially in the southern hemisphere. Together, these results show that over just the last two centuries human beings have induced changes in the global biogeography of freshwater fish body size, which could affect ecosystem properties.
authors.affiliation: Station d'Ecologie Expérimentale du CNRS à Moulis, Moulis, France. blanchet@cict.fr <blanchet@cict.fr>
authors.forename: Simon
authors.initials: S
authors.lastname: Blanchet
authors.forename: Gael
authors.initials: G
authors.lastname: Grenouillet
authors.forename: Olivier
authors.initials: O
authors.lastname: Beauchard
authors.forename: Pablo A
authors.initials: PA
authors.lastname: Tedesco
authors.forename: Fabien
authors.initials: F
authors.lastname: Leprieur
authors.forename: Hans H
authors.initials: HH
authors.lastname: Dürr
authors.forename: Frederic
authors.initials: F
authors.lastname: Busson
authors.forename: Thierry
authors.initials: T
authors.lastname: Oberdorff
authors.forename: Sébastien
authors.initials: S
authors.lastname: Brosse
mesh_terms: D000818:Animals; D049628:Body Size; D002755:Choice Behavior; D017753:Ecosystem; D005399:Fishes; D005843:Geography; D006801:Humans; D046448:Ice Cover; D008954:Models, Biological; D045483:Rivers; D013696:Temperature