SS1.08 Sensory Ecology, Neurophysiology and Behavior of Zooplankton
Date: Monday, June 10, 2002
Time: 11:00:00 AM
Location: Carson B
 
LaforschC, Ludwig-Maximilians-Universität, München, Germany, laforsch@zi.biologie.uni-muenchen.de
Tollrian, R, , Ludwig-Maximilians-Universität, München, Germany, ralph.tollrian@lrz.uni-muenchen.de
 
CYCLOMORPHOSIS IN DAPHNIA CUCULLATA – AN ADAPTATION AGAINST MULTIPREDATION PRESSURES UNDER VARIABLE ENVIRONMENTAL CONDITIONS
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Although cyclomorphosis in Daphnia cucullata is used as a textbook example of phenotypic plasticity, little is known about the proximate and ultimate factors of this phenomenon. We show that phenotypic plasticity of Daphnia cucullata has evolved in response to different environmental conditions. A special kind of small-scale turbulence and chemical cues from different kinds of invertebrate predators (Chaoborus flavicans; Leptodora kindtii; Cyclops spec.; Acari) are proximate factors of cyclomorphosis in Daphnia cucullata. These parameters act synergistically. Small cladocerans such as Daphnia cucullata are prey items for many aquatic invertebrate predators. Therefore we tested the hypothesis that induced helmets offer protection in multipredator environments. Our predation experiments with Chaoborus flavicans, Leptodora kindtii, and Cyclops revealed that the induced morphological changes offered protection against each of the predators tested.