@article{BukovinszkyVerschoorHelmsingetal.2012,
  author    = {Bukovinszky, Tibor and Verschoor, Antonie M. and Helmsing, Nico R. and Bezemer, T. Martijn and Bakker, Elisabeth S. and Vos, Matthijs and Domis, Lisette Nicole de Senerpont},
  title     = {The Good, the bad and the plenty Interactive effects of food quality and quantity on the growth of different daphnia species},
  series = {PLoS one},
  volume    = {7},
  journal   = {PLoS one},
  number    = {9},
  publisher = {PLoS},
  address   = {San Fransisco},
  issn      = {1932-6203},
  doi       = {10.1371/journal.pone.0042966},
  pages     = {8},
  year      = {2012},
  abstract  = {Effects of food quality and quantity on consumers are neither independent nor interchangeable. Although consumer growth and reproduction show strong variation in relation to both food quality and quantity, the effects of food quality or food quantity have usually been studied in isolation. In two experiments, we studied the growth and reproduction in three filter-feeding freshwater zooplankton species, i.e. Daphnia galeata x hyalina, D. pulicaria and D. magna, on their algal food (Scenedesmus obliquus), varying in carbon to phosphorus (C:P) ratios and quantities (concentrations). In the first experiment, we found a strong positive effect of the phosphorus content of food on growth of Daphnia, both in their early and late juvenile development. Variation in the relationship between the P-content of animals and their growth rate reflected interspecific differences in nutrient requirements. Although growth rates typically decreased as development neared maturation, this did not affect these species-specific couplings between growth rate and Daphnia P-content. In the second experiment, we examined the effects of food quality on Daphnia growth at different levels of food quantity. With the same decrease in P-content of food, species with higher estimated P-content at zero growth showed a larger increase in threshold food concentrations (i.e. food concentration sufficient to meet metabolic requirements but not growth). These results suggest that physiological processes such as maintenance and growth may in combination explain effects of food quality and quantity on consumers. Our study shows that differences in response to variation in food quality and quantity exist between species. As a consequence, species-specific effects of food quality on consumer growth will also determine how species deal with varying food levels, which has implications for resource-consumer interactions.},
  language  = {en}
}
@article{BukovinszkyHelmsingGrauetal.2013,
  author    = {Bukovinszky, Tibor and Helmsing, Nico R. and Grau, R. A. and Bakker, Elisabeth S. and Bezemer, T. Martijn and Vos, Matthijs and Uittenhout, H. and Verschoor, A. M.},
  title     = {A device to study the behavioral responses of zooplankton to food quality and quantity},
  series = {Journal of insect behavior},
  volume    = {26},
  journal   = {Journal of insect behavior},
  number    = {4},
  publisher = {Springer},
  address   = {New York},
  issn      = {0892-7553},
  doi       = {10.1007/s10905-012-9366-0},
  pages     = {453 -- 465},
  year      = {2013},
  abstract  = {In order to explore the behavioral mechanisms underlying aggregation of foragers on local resource patches, it is necessary to manipulate the location, quality and quantity of food patches. This requires careful control over the conditions in the foraging arena, which may be a challenging task in the case of aquatic resource-consumer systems, like that of freshwater zooplankton feeding on suspended algal cells. We present an experimental tool designed to aid behavioral ecologists in exploring the consequences of resource characteristics for zooplankton aggregation behavior and movement decisions under conditions where the boundaries and characteristics (quantity and quality) of food patches can be standardized. The aggregation behavior of Daphnia magna and D. galeata x hyalina was tested in relation to i) the presence or absence of food or ii) food quality, where algae of high or low nutrient (phosphorus) content were offered in distinct patches. Individuals of both Daphnia species chose tubes containing food patches and D. galeata x hyalina also showed a preference towards food patches of high nutrient content. We discuss how the described equipment complements other behavioral approaches providing a useful tool to understand animal foraging decisions in environments with heterogeneous resource distributions.},
  language  = {en}
}