Evolutionary Ecology

, Volume 9, Issue 2, pp 131–138 | Cite as

Maintenance of two genetic entities by habitat selection

  • Thierry de Meeûs
  • Michael E. Hochberg
  • François Renaud
Article

Summary

In the laboratory, the two species of copepodsLepeophtheirus thompsoni andLepeophtheirus europaensis, ectoparasites of flatfishes, can meet and mate on at least one host species. In the wild however, these two species are found isolated on their sympatric hosts. Habitat selection theoretically represents a powerful enough mechanism to explain the maintenance of genetic heterogeneity in the wide sense. In this paper, the host colonization process is studied for both parasite species. It is shown that each parasite can develop and reach adult age on each host species. However,L. thompsoni is highly selective; it almost totally refuses to colonize hosts other than its natural one.Lepeophtheirus europaensis, on the contrary, readily infests turbot and brill in single-host experiments, but strongly prefers the brill when it has a choice. It appears that these two genetic entities are sympatrically maintained due to strong habitat selection. Such a pattern could theoretically only occur in a soft-selection context (density dependence). This point is discussed with respect to the different patterns in host use found in the geographical distribution of these parasites.

Keywords

Selected polymorphism habitat selection genetic isolation habitat specialization soft selection competition parasitic copepods specificity 

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Copyright information

© Chapman & Hall 1995

Authors and Affiliations

  • Thierry de Meeûs
    • 1
  • Michael E. Hochberg
    • 2
  • François Renaud
    • 1
  1. 1.Laboratoire de Parasitologie Comparée, CNRS-URA 698Université Montpellier II, Case 105Montpellier Cedex 05France
  2. 2.Ecole Normale Supérieure, CNRS-URA 258Laboratoire d'EcologieParis Cedex 05France

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