Ectotherms tend to mature at smaller sizes as average temperatures rise, a pattern known as the Temperature‐Size Rule (TSR), which also predicts earlier age at maturity. However, in natural environments, warming is often accompanied by increased thermal variability and limited nutritional resources. Using a bioenergetic model combined with factorial growth experiments on Daphnia , we investigated how temperature, food concentr...

In a warming world, acclimation of metabolic rate in aquatic ectotherms has been pointed out as a critical process to offset the temperature‐induced increase of energy requirements and the associated higher oxygen demand. However, this paradigm is drawn from measurements of aerobic energy production as a proxy for metabolic rate, thus overlooking the contribution of anaerobic energy production. Here, we combined individual‐bas...

Organisms exhibit reversible physiological adjustments as a response to rapidly changing environments. Yet such plasticity of the phenotype is gradual and may lag behind environmental fluctuations, thereby affecting long‐term average performance of the organisms. By supplying energy and essential compounds for optimal tissue building, food determines the range of possible phenotypic changes and potentially the rate at which th...

Consumer metabolism controls the energy uptake from the environment and its allocation to biomass production. In natural ecosystems, available energy in food often fails to predict biomass production which is also (co)limited by the relative availability of various dietary compounds. To date, the link between energy metabolism and the effects of food chemical composition on biomass production remains elusive. Here, we measured...

Temperature and nutrient availability, which are major drivers of consumer performance, are dramatically affected by global change. To date, there is no consensus on whether warming increases or decreases consumer needs for dietary carbon (C) relatively to phosphorus (P), thus hindering predictions of secondary production responses to global change. Here, we investigate how the dietary C:P ratio optimising consumer growth ( TE...

Summary Chytrids are ubiquitous fungal parasites in aquatic ecosystems, infecting representatives of all major phytoplankton groups. They repack carbon from inedible phytoplankton hosts into easily ingested chytrid propagules (zoospores), rendering this carbon accessible to zooplankton. Grazing on zoospores may circumvent bottlenecks in carbon transfer imposed by the dominance of inedible or poorly nutritious phytoplankton (my...

Understanding the determinants of metabolism is a core ecological topic since it permits to link individual energetic requirements to the ecology of communities and ecosystems. Yet, besides temperature, metabolic responses to environmental factors remain poorly understood. For example, it is commonly assumed that dietary stoichiometric constraints increase metabolism of small invertebrates despite scarce experimental support....

Huge amounts of pollen can accumulate at the air‐water interface during the floral bloom of wind‐pollinated trees. We hypothesized that such pollen rains act as subsidy pulses, promoting the development of a neustonic microbial food web and the transfer of pollen organic carbon to aquatic consumers. During a pine pollen rain event on an oxbow lake, microorganism concentrations were by far higher in the neuston, where pollen gr...

Pollen rain can lead to considerable allochthonous particulate organic carbon input into freshwater systems. However, the importance of allochthonous pollen deposition for zooplankton production has not so far been considered. Here, standardized growth experiments were performed to assess the quality of pollen from three species ( Alnus sp., Populus sp., and Cedrus sp.) as a food source for two cladocerans ( Daphnia longispina...

We investigated the effect of food quality on somatic growth and reproduction of zooplankton at different temperatures (12°C, 15°C, 20°C, and 25°C). Standardized growth experiments of two cladocerans, Daphnia magna and Simocephalus vetulus , were performed on (1) high‐quality food ( Cryptomonas sp.), (2) relatively low‐quality food ( Scenedesmus obliquus ), and (3) intermediate‐quality food ( Cryptomonas : Scenedesmus mixture)...

We investigated whether trophic repackaging of autotrophic picoplankton by phagotrophic protists is associated with an improvement in food quality for the metazooplankton Daphnia magna (i.e., whether trophic upgrading occurs in this system). The nutritional value of the autotrophic species Microcystis aeruginosa PCC7806, Synechococcus sp. strain BO8809, Synechococcus elongatus SAG 89.79, and Choricystis minor KR1988/ 8, and of...