Naturwissenschaften

, Volume 96, Issue 10, pp 1241–1246

Plant invasion phenomenon enhances reproduction performance in an endangered spider

  • Julien Pétillon
  • Charlène Puzin
  • Anthony Acou
  • Yannick Outreman
SHORT COMMUNICATION

DOI: 10.1007/s00114-009-0589-7

Cite this article as:
Pétillon, J., Puzin, C., Acou, A. et al. Naturwissenschaften (2009) 96: 1241. doi:10.1007/s00114-009-0589-7

Abstract

Current models in evolutionary ecology predict life history alterations in response to habitat suitability to optimize fitness. Only few empirical studies have demonstrated how life history traits that are expected to trade off against each other differ among environments. In Europe, many salt marshes have been recently invaded by the grass Elymus athericus. Previous studies however showed higher densities of the endangered spider Arctosa fulvolineata (Araneae: Lycosidae) in invaded salt marshes compared to natural habitats, which suggests a lower habitat suitability in the latter. The aim of this study was to determine if this emerging habitat (1) affects the amount of resource acquisition and (2) alters the balance between life history traits that are expected to trade off against each other in this stenotopic salt marsh species. As suggested by theoretical studies, an optimization of fitness by increasing egg size at the cost of decreasing fecundity in unsuitable (i.e., natural) habitats was expected. Females presenting cocoon were then collected in close invaded and natural salt marsh areas within the Mont Saint-Michel Bay (France). By considering female mass as covariate, cocoon mass, number of eggs, and egg volume were compared between both habitats. Clutch mass was strongly determined by female mass in both habitats. Clutch mass was however significantly smaller in the natural habitat compared to the invaded habitat, indicating a higher resource acquisition in the latter. When correcting for female size, fecundity was additionally increased in the invaded habitat through a significant decrease in egg size. This phenotypic response can be explained by differences in habitat structure between invaded and natural habitats: the former offers a more complex litter favoring nocturnal wanderers like A. fulvolineata. The existence of such an adaptive reproduction strategy depending on habitat suitability constitutes an original case of an invasion that favors an endangered species.

Keywords

Biological invasionLife history traitsPhenotypic plasticityRare speciesTrade-off

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Julien Pétillon
    • 1
    • 2
  • Charlène Puzin
    • 1
  • Anthony Acou
    • 3
  • Yannick Outreman
    • 4
  1. 1.U.R.U. 420—“Biodiversité fonctionnelle et Gestion des territoires”Université de Rennes 1Rennes CedexFrance
  2. 2.Terrestrial Ecology Unit (TEREC)Ghent UniversityGhentBelgium
  3. 3.U.M.R. 7208—“Biologie des Organismes et Écosystèmes Aquatiques”Muséum National d’Histoire Naturelle, Station Marine de DinardDinardFrance
  4. 4.U.M.R. 1099—INRA-Agrocampus Ouest-Université Rennes 1 “Biologie des Organismes et des Populations appliquée à la Protection des Plantes”Rennes CedexFrance