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Non‐native species disrupt the worldwide patterns of freshwater fish body size: implications for Bergmann’s rule
Author(s) -
Blanchet Simon,
Grenouillet Gael,
Beauchard Olivier,
Tedesco Pablo A.,
Leprieur Fabien,
Dürr Hans H.,
Busson Frederic,
Oberdorff Thierry,
Brosse Sébastien
Publication year - 2010
Publication title -
ecology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.852
H-Index - 265
eISSN - 1461-0248
pISSN - 1461-023X
DOI - 10.1111/j.1461-0248.2009.01432.x
Subject(s) - freshwater fish , ecology , abiotic component , biology , fish <actinopterygii> , introduced species , freshwater ecosystem , ecosystem , southern hemisphere , fishery
Ecology Letters (2010) 13: 421–431 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.