Inducible responses in the brown seaweed Ecklonia cava: the role of grazer identity and season

Authors

  • MARKUS MOLIS,

    Corresponding author
    1. Biological Station Helgoland, Alfred-Wegener-Institute for Polar and Marine Research, Kurpromenade 201, D-27498 Helgoland, Germany,
      Markus Molis (tel. +49 4725 819 239; fax +49 4725 819 283; e-mail mmolis@awi-bremerhaven.de).
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  • JOCHEN KÖRNER,

    1. Institute for Chemistry and Biology of the Marine Environment (ICBM), Aquatic Ecology, Carl von Ossietzky University, Ammerländer Heerstraße 114–118, D-26129 Oldenburg, Germany,
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  • YOUNG WOOK KO,

    1. Department of Biological Science, Sungkyunkwan University, Suwon, 440–746, South Korea, and
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  • JEONG HA KIM,

    1. Department of Biological Science, Sungkyunkwan University, Suwon, 440–746, South Korea, and
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  • MARTIN WAHL

    1. Leibniz Institute of Marine Science, University Kiel, Düsternbrooker Weg 20, D-24105 Kiel, Germany
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Markus Molis (tel. +49 4725 819 239; fax +49 4725 819 283; e-mail mmolis@awi-bremerhaven.de).

Summary

  • 1Plants must either tolerate consumption or defend themselves against grazer attacks. Selection for phenotypically plastic antiherbivory responses has been suggested for many plants, including a few species of seaweed, but little is known about its specificity or seasonality.
  • 2Multi-factorial experiments tested the effects of consumer identity (Littorina brevicula vs. Haliotis discus) and season (summer vs. autumn) on the induction of antiherbivory defences in the brown seaweed Ecklonia cava. Following a grazer-free acclimation phase, algae were incubated with grazers (treatment phase) and, subsequently, without grazers (recovery phase). Feeding preference assays, were used to assess differences in consumption rates between grazer-exposed and control plants.
  • 3In summer, Littorina, but not Haliotis, induced defence in Ecklonia. This defence vanished by the end of the recovery phase. In autumn, neither exposure to direct attack nor to waterborne cues induced defensive responses.
  • 4Both consumer identity and season of consumption can influence the ability of a given macroalgal species to induce antiherbivory defences. Tailoring such responses to spatial and temporal variation in grazer pressure could have profound ecological implications, for example changing food webs and community structure.

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