Trematode cercariae as prey for zooplankton: effect on fitness traits of predators.

摘要: Removal of parasite free-living stages by predators has previously been suggested an important factor controlling transmission in aquatic habitats. Experimental studies zooplankton predation on macroparasite larvae are, however, scarce. We tested whether trematode cercariae, which are often numerous shallow waters, suitable prey for syntopic zooplankters. Feeding rates and survival freshwater cyclopoids (Megacyclops viridis, Macrocyclops distinctus), calanoids (Arctodiaptomus paulseni), cladocerans (Sida crystallina) rotifers Asplanchna spp., fed with cercariae Diplostomum pseudospathaceum, a common fish trematode, were studied. In additional long-term experiments, we studied reproduction cercariae. All species consumed The highest feeding observed (33 ± 12 ind-1 h-1), actively reproduced (up to one egg clutch day-1) when ad libitum Their reproductive characteristics did not change significantly time, indicating that supported cyclopoids' dietary needs. Mortality was high (25-28% individuals) exposed contrast (<2%). Cercariae clogged the filtration apparatus caused internal injuries predatory rotifers, ingested Observed trophic links between zooplankters may influence food webs lentic ecosystems.