@article{KoussoroplisSchaelickeRaatzetal.2019, author = {Koussoroplis, Apostolos-Manuel and Sch{\"a}licke, Svenja and Raatz, Michael and Bach, Moritz and Wacker, Alexander}, title = {Feeding in the frequency domain}, series = {Ecology letters}, volume = {22}, journal = {Ecology letters}, number = {7}, publisher = {Wiley}, address = {Hoboken}, issn = {1461-023X}, doi = {10.1111/ele.13267}, pages = {1104 -- 1114}, year = {2019}, abstract = {Theory predicts that resource variability hinders consumer performance. How this effect depends on the temporal structure of resource fluctuations encountered by individuals remains poorly understood. Combining modelling and growth experiments with Daphnia magna, we decompose the complexity of resource fluctuations and test the effect of resource variance, supply peak timing (i.e. phase) and co-limiting resource covariance along a gradient from high to low frequencies reflecting fine- to coarse-grained environments. Our results show that resource storage can buffer growth at high frequencies, but yields a sensitivity of growth to resource peak timing at lower ones. When two resources covary, negative covariance causes stronger growth depression at low frequencies. However, negative covariance might be beneficial at intermediate frequencies, an effect that can be explained by digestive acclimation. Our study provides a mechanistic basis for understanding how alterations of the environmental grain size affect consumers experiencing variable nutritional quality in nature.}, language = {en} } @article{DenouxMartinCreuzburgKoussoroplisetal.2017, author = {Denoux, Clemence and Martin-Creuzburg, Dominik and Koussoroplis, Apostolos-Manuel and Perriere, Fanny and Desvillettes, Christian and Bourdier, Gilles and Bec, Alexandre}, title = {Phospholipid-bound eicosapentaenoic acid (EPA) supports higher fecundity than free EPA in Daphnia magna}, series = {Journal of plankton research}, volume = {39}, journal = {Journal of plankton research}, publisher = {Oxford Univ. Press}, address = {Oxford}, issn = {0142-7873}, doi = {10.1093/plankt/fbx037}, pages = {843 -- 848}, year = {2017}, abstract = {Nutrition bioassays in which polyunsaturated fatty acids (PUFA)-deficient diets were supplemented with free long-chain PUFA (>= C20) consistently revealed positive effects on somatic growth and fecundity of Daphnia. However, free PUFA are hardly available in natural diets. In general, PUFA are bound to other lipids, especially to phospholipids and triglycerides. Here, we evaluate the potential of free and phospholipid-bound dietary eicosapentaenoic acid (EPA) to support somatic growth and fecundity of Daphnia magna. In a growth experiment, supplementation of a C20 PUFA-deficient diet with free or phospholipid-bound EPA improved somatic growth rates of D. magna equally. However, the increase in fecundity was significantly more pronounced when phospholipid-bound EPA was provided. Free and phospholipid-bound EPA were provided in the same concentrations in our experiment, suggesting that the allocation to reproduction-related processes is affected differently by phospholipid-bound PUFA and free PUFA. Our finding stresses the need to consider the distribution of dietary PUFA in different lipid classes to gain a better understanding of how PUFA influence life history traits of Daphnids in the field.}, language = {en} }