Differences in zooplankton feeding rates and isotopic signatures from three temperate lakes

摘要: Bacteria and phytoplankton are integral in the mobilization transfer of organic matter to higher trophic levels. Hence, we examined their role zooplankton diets assessed trends nitrogen isotopic variability. We performed feeding experiments with natural particulate (POM) four groups (Daphnia, Holopedium, large calanoids small calanoids) (1) examine whether there differences consumption (presented as clearance ingestion rates) bacteria, (2) determine rates correlated δ15N signatures. In general, bacteria biomass ingested per animal varied significantly among different within lakes between for a given group. Within lake, Daphnia Holopedium had highest rates, followed by calanoids, then calanoids. For group, lakes. contrast, were consistently Dickie Lake all taxa, whereas more variable taxa. The percentage contribution taxa also but few lake zooplankton. Zooplankton δ15NDOMC values size adjusted rates. correlations stronger compared biomass. Together our results suggest that low likely exploiting food sources from