Biological Invasions

, Volume 12, Issue 1, pp 191–209

Reduction in post-invasion genetic diversity in Crangonyx pseudogracilis (Amphipoda: Crustacea): a genetic bottleneck or the work of hitchhiking vertically transmitted microparasites?

Authors

  • Johanna G. M. Slothouber Galbreath
    • Faculty of Biological Sciences, Institute of Integrative and Comparative BiologyUniversity of Leeds
    • Institute of Biological and Environmental SciencesUniversity of Aberdeen
  • Judith E. Smith
    • Faculty of Biological Sciences, Institute of Integrative and Comparative BiologyUniversity of Leeds
  • James J. Becnel
    • USDA/ARSCenter for Medical, Agricultural and Veterinary Entomology
  • Roger K. Butlin
    • Department of Animal and Plant SciencesUniversity of Sheffield
    • Faculty of Biological Sciences, Institute of Integrative and Comparative BiologyUniversity of Leeds
Original Paper

DOI: 10.1007/s10530-009-9442-3

Cite this article as:
Slothouber Galbreath, J.G.M., Smith, J.E., Becnel, J.J. et al. Biol Invasions (2010) 12: 191. doi:10.1007/s10530-009-9442-3

Abstract

Parasites can strongly influence the success of biological invasions. However, as invading hosts and parasites may be derived from a small subset of genotypes in the native range, it is important to examine the distribution and invasion of parasites in the context of host population genetics. We demonstrate that invasive European populations of the North American Crangonyx pseudogracilis have experienced a reduction in post-invasion genetic diversity. We predict that vertically transmitted parasites may evade the stochastic processes and selective pressures leading to enemy release. As microsporidia may be vertically or horizontally transmitted, we compared the diversity of these microparasites in the native and invasive ranges of the host. In contrast to the reduction in host genetic diversity, we find no evidence for enemy release from microsporidian parasites in the invasive populations. Indeed, a single, vertically transmitted, microsporidian sex ratio distorter dominates the microsporidian parasite assemblage in the invasive range and appears to have invaded with the host. We propose that overproduction of female offspring as a result of parasitic sex ratio distortion may facilitate host invasion success. We also propose that a selective sweep resulting from the increase in infected individuals during the establishment may have contributed to the reduction in genetic diversity in invasive Crangonyx pseudogracilis populations.

Keywords

Biological invasionsEnemy releaseEmergent diseaseMicrosporidiaSex ratio distortionVertical transmission

Supplementary material

10530_2009_9442_MOESM1_ESM.doc (21 kb)
(DOC 90 kb)

Copyright information

© Springer Science+Business Media B.V. 2009