Biological Invasions

, Volume 3, Issue 4, pp 333–345

Release from Parasites as Natural Enemies: Increased Performance of a Globally Introduced Marine Crab

  • Mark E. Torchin
  • Kevin D. Lafferty
  • Armand M. Kuris
Article

DOI: 10.1023/A:1015855019360

Cite this article as:
Torchin, M.E., Lafferty, K.D. & Kuris, A.M. Biological Invasions (2001) 3: 333. doi:10.1023/A:1015855019360

Abstract

Introduced species often seem to perform better than conspecifics in their native range. This is apparent in the high densities they may achieve or the larger individual sizes they attain. A prominent hypothesis explaining the success of introduced terrestrial species is that they are typically free of or are less affected by the natural enemies (competitors, predators, and parasites) they encounter in their introduced range compared to their native range. To test this hypothesis in a marine system, we conducted a global assessment of the effect of parasitism and predation on the ecological performance of European green crab populations. In Europe, where the green crab is native, crab body size and biomass were negatively associated with the prevalence of parasitic castrators. When we compared native crab populations with those from introduced regions, limb loss (an estimator of predation) was not significantly lower in introduced regions, parasites infected introduced populations substantially less and crabs in introduced regions were larger and exhibited a greater biomass. Our results are consistent with the general prediction that introduced species suffer less from parasites compared to populations where they are native. This may partly explain why the green crab is such a successful invader and, subsequently, why it is a pest in so many places.

Carcinus maenas green crab introduced species natural enemies parasites predators global invasion 

Copyright information

© Kluwer Academic Publishers 2001

Authors and Affiliations

  • Mark E. Torchin
    • 1
  • Kevin D. Lafferty
    • 2
  • Armand M. Kuris
    • 1
  1. 1.Marine Science Institute and Department of Ecology, Evolution and Marine BiologyUniversity of CaliforniaSanta BarbaraUSA; Author for correspondence (e-mail
  2. 2.US Geological Survey, Western Ecological Research Center, c/o Marine Science InstituteUniversity of CaliforniaSanta BarbaraUSA

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