English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

In the stoichiometric study of phyto–zooplankton interactions, a controversy exists about how  Daphnia  species regulate their feeding rate when submitted to low-quality food (i.e. high dietary carbon:phosphorus [C:P] ratio). In this study, we gathered data over 3 years on  in situ  clearance rates of a  Daphnia galeata  population, by conducting grazing experiments from April 1998 to October 2000 in the Esch-sur-Sûre reservoir (Grand-Duchy of Luxembourg). Observed clearance rates (2.5–13.5 mL individual −1  day −1 , mean 7.0 mL individual −1  day −1 ) were correlated with population and environmental variables. Mean body size of  Daphnia  individuals was the best predictor of clearance rate ( r  2  = 0.639), followed by water temperature ( r  2  = 0.262) and P concentration in the seston ( r  2  ≤ 0.241). When combined with body size, seston C:P or nitrogen:P ratios provided the best predictive regression model of clearance rate ( r  2  = 0.852–0.897). The clearance rate was always correlated negatively with P concentration in the food. Thus,  Daphnia  reacts to a decrease of food quality (i.e. higher C:P ratio) by an increase of its feeding rate. However, the filtration response to food quality was inhibited by high population density. We suggest that, when food quality is low and population density high, this inhibition may favour fitness of future conspecific generations. In conclusion, our results emphasize the effect of P availability on transfer rate of organic matter between lacustrian autotrophs and herbivores and pose questions about consequent effects on nutrient biogeochemical cycles.

In situ filtration responses of Daphnia galeata to changes in food quality