Brewer, M. C. University of Wisconsin, mcbrewer@facstaff.wisc.edu
Plath, K. C. Max-Planck Institute for Limnology, plath@mpil-ploen.mpg.de

 
FORAGING IN A HETEROGENEOUS ENVIRONMENT: THE ABILITY OF DAPHNIA TO EXPLOIT ALGAL PATCHES
 
In nature, resources are generally heterogeneously distributed. Though the extent of algal patchiness in lakes is not fully known, variation in algal concentrations certainly exists both vertically and horizontally. The ability to respond to and exploit this heterogeneity would be of obvious benefit to Daphnia, the dominant grazer in many freshwater environments. Recent evidence indicates that Daphnia respond behaviorally to food gradients, but the ability of Daphnia to exploit patches of algae, and the dynamics of such an interaction remain largely unexplored. Here we present evidence that Daphnia can recognize and exploit patches of algae. Based on observations of populations of Daphnia in 10 cm diameter, 1 m tall tubes, we describe the dynamics of finding, harvesting and leaving an artificially created patch of food. We also discuss interspecific differences in these dynamics, and the potential effects of these differences on community and ecosystem interactions.
 
Day: Monday, Feb. 1
Time: 03:30 - 03:45pm
Location: Sweeney Center
 
Code: SS01MO0330S