Biological Invasions

, Volume 19, Issue 5, pp 1407–1420 | Cite as

Cryptic invasion of Italian pool frogs (Pelophylax bergeri) across Western Europe unraveled by multilocus phylogeography

  • Christophe Dufresnes
  • Lionel Di Santo
  • Julien Leuenberger
  • Johan Schuerch
  • Glib Mazepa
  • Nathalie Grandjean
  • Daniele Canestrelli
  • Nicolas Perrin
  • Sylvain Dubey
Original Paper


Human introductions of exotic amphibians can have catastrophic effects on native species. However, they usually remain unnoticed without genetic tools when species are difficult to distinguish morphologically. In Western Europe, pool frogs (Pelophylax sp.) make a worrisome case: recent genetic data showed the presence of Italian (Pelophylax bergeri) mtDNA haplotypes within the range of the threatened European Pelophylax lessonae, two morphologically similar taxa. Here we conduct a multilocus phylogeographic and population genetic survey of European and Italian pool frogs (combining present and historic samples), to investigate the origin(s) and consequences of potential introductions. Results are unequivocal: we show that the alien P. bergeri have extensively invaded France and north-Alpine Switzerland, and have also deeply introgressed with P. lessonae, which has led to the complete replacement of most populations. Alien specimens have probably been translocated multiple times from Central Italy at least prior to the 1960s. Based on our dense sampling, only two areas, north and south of the Alps still host native pool frogs in Switzerland, the Joux Valley near the French border and the canton of Ticino, respectively. Importantly, we show that these last P. lessonae populations are remnants of a private genetic diversity specific to Western Europe, which vanished during the P. bergeri’s invasion. Our study emphasizes the risk of genetic pollution during invasion by human-introduced taxa and brings alarming concern regarding uncontrolled amphibian translocations. Moreover, it demonstrates the necessity for genetic surveys to detect and monitor these invasions, especially where species determination is problematic.


Europe Human introduction Introgression Invasion Ranid frogs Pelophylax bergeri Pelophylax lessonae 



We greatly thank the Federal Office for the Environment (FOEN / OFEV / BAFU; Francis Cordillot) and the state of Geneva (G. Dandliker) for funding and the karch (J. Pellet, S. Ursenbacher, B. Schmidt, T. Bohnenstengel, and S. Zumbach) for support, and M.L. Kieffer, H. Schmoker, B. Schmidt, T. Maddalena, karch-GE (J. Thiébaud), the University of Zürich (Reyer Group), the Museum of Natural History of the City of Geneva, the Museum of Natural History of the City of Vienna, the National Museum of Natural History of Paris, the Cantonal Museum of Zoology (Vaud), and the karch for tissue samples. We are grateful to Dr. D.L. Jeffries (University of Lausanne) for his useful comments and edits on the manuscript and Olga Dubey for support.

Supplementary material

10530_2016_1359_MOESM1_ESM.xlsx (60 kb)
File S1 Detailed sampling information (XLSX 60 kb)
10530_2016_1359_MOESM2_ESM.pdf (14 kb)
File S2 Microsatellite information (PDF 13 kb)
10530_2016_1359_MOESM3_ESM.pdf (15 kb)
File S3 Summary statistics used in the ABC analysis (PDF 15 kb)
10530_2016_1359_MOESM4_ESM.pdf (243 kb)
File S4 Phylogeny of mitochondrial haplotypes (PDF 243 kb)


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Copyright information

© Springer International Publishing Switzerland 2016

Authors and Affiliations

  • Christophe Dufresnes
    • 1
  • Lionel Di Santo
    • 1
  • Julien Leuenberger
    • 1
  • Johan Schuerch
    • 1
  • Glib Mazepa
    • 1
  • Nathalie Grandjean
    • 1
    • 2
  • Daniele Canestrelli
    • 3
  • Nicolas Perrin
    • 1
  • Sylvain Dubey
    • 1
    • 4
  1. 1.Department of Ecology and EvolutionUniversity of LausanneLausanneSwitzerland
  2. 2.Direction générale de l’environnementDivision Biodiversité et paysageSaint-SulpiceSwitzerland
  3. 3.Department of Ecology and BiologyTuscia UniversityViterboItaly
  4. 4.Hintermann & Weber SAMontreuxSwitzerland

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