@misc{WagnerHillebrandWackeretal.2013,
  author    = {Wagner, Nicole D. and Hillebrand, Helmut and Wacker, Alexander and Frost, Paul C.},
  title     = {Nutritional indicators and their uses in ecology},
  series = {Ecology letters},
  volume    = {16},
  journal   = {Ecology letters},
  number    = {4},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {1461-023X},
  doi       = {10.1111/ele.12067},
  pages     = {535 -- 544},
  year      = {2013},
  abstract  = {The nutrition of animal consumers is an important regulator of ecological processes due to its effects on their physiology, life-history and behaviour. Understanding the ecological effects of poor nutrition depends on correctly diagnosing the nature and strength of nutritional limitation. Despite the need to assess nutritional limitation, current approaches to delineating nutritional constraints can be non-specific and imprecise. Here, we consider the need and potential to develop new complementary approaches to the study of nutritional constraints on animal consumers by studying and using a suite of established and emerging biochemical and molecular responses. These nutritional indicators include gene expression, transcript regulators, protein profiling and activity, and gross biochemical and elemental composition. The potential applications of nutritional indicators to ecological studies are highlighted to demonstrate the value that this approach would have to future studies in community and ecosystem ecology.},
  language  = {en}
}
@article{LukasFrostWacker2013,
  author    = {Lukas, Marcus and Frost, Paul C. and Wacker, Alexander},
  title     = {The neonate nutrition hypothesis - early feeding affects the body stoichiometry of Daphnia offspring},
  series = {Freshwater biology},
  volume    = {58},
  journal   = {Freshwater biology},
  number    = {11},
  publisher = {Wiley-Blackwell},
  address   = {Hoboken},
  issn      = {0046-5070},
  doi       = {10.1111/fwb.12213},
  pages     = {2333 -- 2344},
  year      = {2013},
  abstract  = {Aquatic herbivores consume variable quantities and qualities of food. In freshwater systems, where phosphorus (P) is often a primary limiting element, inadequate dietary P can slow maternal growth and reduce body P content. There remains uncertainty about whether and how dietary effects on mothers are transferred to offspring by way of egg provisioning. Using the keystone herbivore Daphnia, we tested a novel explanation (the neonate nutrition hypothesis') to determine whether the early nutrition of newborns affects their elemental composition and whether the indications of differences in maternal P nutrition found previously might be overestimated. We thus examined the P content of mothers and their eggs from deposition through development to the birth of neonates. We examined further whether very short periods of ingestion (3h) by the offspring alter the overall P content of juvenile Daphnia. We showed that strong dietary P effects on mothers were not directly transferred to their eggs. Irrespective of the supply of P in the maternal diet, the P content of eggs in different developmental stages and in (unfed) neonates did not differ. This indicates that Daphnia mothers do not reduce the quality (in terms of P) of newly produced offspring after intermittent periods (i.e. several days) of poor nutrition. In contrast, the P content of neonates reflected that of their food after brief periods of feeding, indicating that even temporary exposure to nutrient poor food immediately after birth may strongly affect the elemental composition of neonates. Our results thus support the neonate nutrition hypothesis, which, like differential maternal provisioning, is a possible explanation for the variable elemental quality of young Daphnia.},
  language  = {en}
}
@article{HartwichMartinCreuzburgWacker2013,
  author    = {Hartwich, Melanie and Martin-Creuzburg, Dominik and Wacker, Alexander},
  title     = {Seasonal changes in the accumulation of polyunsaturated fatty acids in zooplankton},
  series = {Journal of plankton research},
  volume    = {35},
  journal   = {Journal of plankton research},
  number    = {1},
  publisher = {Oxford Univ. Press},
  address   = {Oxford},
  issn      = {0142-7873},
  doi       = {10.1093/plankt/fbs078},
  pages     = {121 -- 134},
  year      = {2013},
  abstract  = {In aquatic food webs, consumers, such as daphnids and copepods, differ regarding their accumulation of polyunsaturated fatty acids (PUFAs). We tested if the accumulation of PUFAs in a seston size fraction containing different consumers and in Daphnia as a separate consumer is subject to seasonal changes in a large deep lake due to changes in the dietary PUFA supply and specific demands of different consumers. We found that the accumulation of arachidonic acid (ARA) in Daphnia increased from early summer to late summer and autumn. However, ARA requirements of Daphnia appeared to be constant throughout the year, because the accumulation of ARA increased when the dietary ARA supply decreased. In the size fraction 140 m, we found an increased accumulation of docosahexaenoic acid (DHA) during late summer and autumn. These seasonal changes in DHA accumulation were linked to changes in the proportion of copepods in this size fraction, which may have increasingly accumulated DHA for active overwintering. We show that consumer-specific PUFA demands can result in seasonal changes in PUFA accumulation, which may influence the trophic transfer of PUFAs within the food web.},
  language  = {en}
}