TY - JOUR A1 - Denoux, Clemence A1 - Martin-Creuzburg, Dominik A1 - Koussoroplis, Apostolos-Manuel A1 - Perriere, Fanny A1 - Desvillettes, Christian A1 - Bourdier, Gilles A1 - Bec, Alexandre T1 - Phospholipid-bound eicosapentaenoic acid (EPA) supports higher fecundity than free EPA in Daphnia magna JF - Journal of plankton research N2 - 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. KW - Daphnia magna KW - food quality KW - phospholipids KW - polyunsaturated fatty acids KW - reproduction KW - somatic growth KW - trophic interactions Y1 - 2017 U6 - https://doi.org/10.1093/plankt/fbx037 SN - 0142-7873 SN - 1464-3774 VL - 39 SP - 843 EP - 848 PB - Oxford Univ. Press CY - Oxford ER - TY - JOUR A1 - Koussoroplis, Apostolos-Manuel A1 - Nussbaumer, Julia A1 - Arts, Michael T. A1 - Guschina, Irina A. A1 - Kainz, Martin J. T1 - Famine and feast in a common freshwater calanoid: Effects of diet and temperature on fatty acid dynamics of Eudiaptomus gracilis JF - Limnology and oceanography N2 - We investigated the effects of temperature (4 degrees C, 8 degrees C, and 12 degrees C) on structural and storage dynamics, as measured by changes in fatty acids (FA) associated with cell membrane phospholipids (PL) and triacylglycerols (TAG), respectively, as well as on body weight and survival of a freshwater calanoid copepod (Eudiaptomus gracilis) during fasting (10 d) and refeeding (10 d) with two algae of differing nutritional quality (Cryptomonas ozolinii and Scenedesmus obliquus). Fasting led to 50% loss in body weight, a near total depletion of TAG, and a drastic decrease of the polyunsaturated FA (PUFA) in TAG and PL, indicating their preferential utilization and alterations in membrane function, respectively. Higher temperatures accelerated the decrease of body weight and of PUFA in PL and TAG, and decreased survival. After 10 d of refeeding, copepods partially recovered their initial lipid stores and cell membrane composition. The effects of food quality were temperature dependent: Cryptomonas promoted better recovery (i.e., return to or close to the levels at the beginning of the experiment) of both body weight and TAG at only the two higher temperatures (8 degrees C and 12 degrees C), whereas no recovery was observed at 4 degrees C. Higher temperatures and refeeding on Cryptomonas also had a positive, but minor, influence on the recovery of membrane FA composition. Survival differed among treatments but was lowest at the intermediate temperature (8 degrees C) for both diets. We conclude that temperature changes on the order of 4-8 degrees C significantly influence TAG and PL during fasting periods and interact with food quality to determine the extent of recovery in copepod lipids. Y1 - 2014 U6 - https://doi.org/10.4319/lo.2014.59.3.0947 SN - 0024-3590 SN - 1939-5590 VL - 59 IS - 3 SP - 947 EP - 958 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Koussoroplis, Apostolos-Manuel A1 - Pincebourde, Sylvain A1 - Wacker, Alexander T1 - Understanding and predicting physiological performance of organisms in fluctuating and multifactorial environments JF - Ecological monographs : a publication of the Ecological Society of America. N2 - Understanding how variance in environmental factors affects physiological performance, population growth, and persistence is central in ecology. Despite recent interest in the effects of variance in single biological drivers, such as temperature, we have lacked a comprehensive framework for predicting how the variances and covariances between multiple environmental factors will affect physiological rates. Here, we integrate current theory on variance effects with co-limitation theory into a single unified conceptual framework that has general applicability. We show how the framework can be applied (1) to generate mathematically tractable predictions of the physiological effects of multiple fluctuating co-limiting factors, (2) to understand how each co-limiting factor contributes to these effects, and (3) to detect mechanisms such as acclimation or physiological stress when they are at play. We show that the statistical covariance of co-limiting factors, which has not been considered before, can be a strong driver of physiological performance in various ecological contexts. Our framework can provide powerful insights on how the global change-induced shifts in multiple environmental factors affect the physiological performance of organisms. KW - co-limitation KW - covariance KW - eco-physiology KW - feeding rate KW - global change KW - multiple stressors KW - nonlinear averaging KW - nutrients KW - scale transition KW - temperature KW - temporal ecology KW - variance Y1 - 2017 U6 - https://doi.org/10.1002/ecm.1247 SN - 0012-9615 SN - 1557-7015 VL - 87 SP - 178 EP - 197 PB - Wiley CY - Hoboken ER - TY - GEN A1 - Koussoroplis, Apostolos-Manuel A1 - Schwarzenberger, Anke A1 - Wacker, Alexander T1 - Diet quality determines lipase gene expression and lipase/esterase activity in Daphnia pulex N2 - We studied the short- (12 h) and long-term (144 h) response of Daphnia pulex lipases to quality shifts in diets consisting of different mixtures of the green alga Scenedesmus with the cyanobacterium Synechococcus, two species with contrasting lipid compositions. The lipase/esterase activity in both the gut and the body tissues had fast responses to the diet shift and increased with higher dietary contributions of Synechococcus. When screening the Daphnia genome for TAG lipases, we discovered a large gene-family expansion of these enzymes. We used a subset of eight genes for mRNA expression analyses and distinguished between influences of time and diet on the observed gene expression patterns. We identified five diet-responsive lipases of which three showed a sophisticated short- and long-term pattern of expression in response to small changes in food-quality. Furthermore, the gene expression of one of the lipases was strongly correlated to lipase/esterase activity in the gut suggesting its potentially major role in digestion. These findings demonstrate that the lipid-related enzymatic machinery of D. pulex is finely tuned to diet and might constitute an important mechanism of physiological adaptation in nutritionally complex environments. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 336 KW - Cyanobacteria KW - Digestive enzyme activity KW - Nutritional quality KW - Lipases Y1 - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-395661 ER - TY - JOUR A1 - Koussoroplis, Apostolos-Manuel A1 - Schwarzenberger, Anke A1 - Wacker, Alexander T1 - Diet quality determines lipase gene expression and lipase/esterase activity in Daphnia pulex JF - Biology open : BiO N2 - We studied the short- (12 h) and long-term (144 h) response of Daphnia pulex lipases to quality shifts in diets consisting of different mixtures of the green alga Scenedesmus with the cyanobacterium Synechococcus, two species with contrasting lipid compositions. The lipase/esterase activity in both the gut and the body tissues had fast responses to the diet shift and increased with higher dietary contributions of Synechococcus. When screening the Daphnia genome for TAG lipases, we discovered a large gene-family expansion of these enzymes. We used a subset of eight genes for mRNA expression analyses and distinguished between influences of time and diet on the observed gene expression patterns. We identified five diet-responsive lipases of which three showed a sophisticated short- and long-term pattern of expression in response to small changes in food-quality. Furthermore, the gene expression of one of the lipases was strongly correlated to lipase/esterase activity in the gut suggesting its potentially major role in digestion. These findings demonstrate that the lipid-related enzymatic machinery of D. pulex is finely tuned to diet and might constitute an important mechanism of physiological adaptation in nutritionally complex environments. KW - Cyanobacteria KW - Digestive enzyme activity KW - Nutritional quality KW - Lipases Y1 - 2017 U6 - https://doi.org/10.1242/bio.022046 VL - 6 SP - 210 EP - 216 PB - The company of Biologists CY - Cambridge ER - TY - JOUR A1 - Koussoroplis, Apostolos-Manuel A1 - Schälicke, Svenja A1 - Raatz, Michael A1 - Bach, Moritz A1 - Wacker, Alexander T1 - Feeding in the frequency domain BT - Coarser-grained environments increase consumer sensitivity to resource variability, covariance and phase JF - Ecology letters N2 - 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. KW - Cholesterol KW - covariance KW - Daphnia KW - digestive acclimation KW - dynamic energy budgets KW - food quality KW - phosphorus KW - storage KW - unbalanced diets Y1 - 2019 U6 - https://doi.org/10.1111/ele.13267 SN - 1461-023X SN - 1461-0248 VL - 22 IS - 7 SP - 1104 EP - 1114 PB - Wiley CY - Hoboken ER - TY - JOUR A1 - Koussoroplis, Apostolos-Manuel A1 - Wacker, Alexander T1 - Covariance modulates the effect of joint temperature and food variance on ectotherm life-history traits JF - Ecology letters N2 - Understanding animal performance in heterogeneous or variable environments is a central question in ecology. We combine modelling and experiments to test how temperature and food availability variance jointly affect life-history traits of ectotherms. The model predicts that as mean temperatures move away from the ectotherm's thermal optimum, the effect size of joint thermal and food variance should become increasingly sensitive to their covariance. Below the thermal optimum, performance should be positively correlated with food–temperature covariance and the opposite is predicted above it. At lower temperatures, covariance should determine whether food and temperature variance increases or decreases performance compared to constant conditions. Somewhat stronger than predicted, the covariance effect below the thermal optimum was confirmed experimentally on an aquatic ectotherm (Daphnia magna) exposed to diurnal food and temperature variance with different amounts of covariance. Our findings have important implications for understanding ectotherm responses to climate-driven alterations of thermal mean and variance. KW - Biotic interactions KW - co-limitation KW - Daphnia KW - environmental fluctuations KW - heterogeneity KW - variability KW - vertical migration KW - zooplankton Y1 - 2016 U6 - https://doi.org/10.1111/ele.12546 SN - 1461-023X SN - 1461-0248 VL - 19 SP - 143 EP - 152 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Marzetz, Vanessa A1 - Koussoroplis, Apostolos-Manuel A1 - Martin-Creuzburg, Dominik A1 - Striebel, Maren A1 - Wacker, Alexander T1 - Linking primary producer diversity and food quality effects on herbivores: A biochemical perspective JF - Scientific reports N2 - Biodiversity can strongly influence trophic interactions. The nutritional quality of prey communities and how it is related to the prey diversity is suspected to be a major driver of biodiversity effects. As consumer growth can be co-limited by the supply of several biochemical components, biochemically diverse prey communities should promote consumer growth. Yet, there is no clear consensus on how prey specific diversity is linked to community biochemical diversity since previous studies have considered only single nutritional quality traits. Here, we demonstrate that phytoplankton biochemical traits (fatty acids and sterols) can to a large extent explain Daphnia magna growth and its apparent dependence on phytoplankton species diversity. We find strong correlative evidence between phytoplankton species diversity, biochemical diversity, and growth. The relationship between species diversity and growth was partially explained by the fact that in many communities Daphnia was co-limited by long chained polyunsaturated fatty acids and sterols, which was driven by different prey taxa. We suggest that biochemical diversity is a good proxy for the presence of high food quality taxa, and a careful consideration of the distribution of the different biochemical traits among species is necessary before concluding about causal links between species diversity and consumer performance. Y1 - 2017 U6 - https://doi.org/10.1038/s41598-017-11183-3 SN - 2045-2322 VL - 7 PB - Nature Publ. Group CY - London ER -