Crustacean Zooplankton Ingestion of Potentially Toxic : In Situ Estimation Using Gene Gut Content Detection in a Large Temperate Eutrophic Lake.

Grazing by zooplankton can regulate bloom-forming cyanobacteria but can also transfer toxin-producing cells, as well as toxic metabolites, to the food web. While laboratory investigations have provided extensive knowledge on zooplankton and toxic cyanobacteria interactions, information on zooplankton feeding on toxin-producing cyanobacteria in natural water bodies remains scarce. In this study, we quantified -specific synthase genes from the gut contents of various cladoceran and copepod taxa to assess the in situ crustacean community and taxon-specific ingestion of potentially toxic in Lake Peipsi, a large eutrophic lake in Estonia, Northern Europe. cells with genes were found in all crustaceans examined. However, some species, such as the cyclopoid copepod , were more efficient in ingesting potentially toxic than other co-occurring cladocerans ( spp., spp., ) and copepods (). The amount of toxigenic cells grazed by crustacean population changed temporarily, and copepods were the predominant consumers of toxigenic during several months of the 5-month study period. Crustacean ingestion of toxigenic was not related to biomass or gene copy numbers in the environment but was instead related to the abundance of major crustacean grazers. Our findings emphasize the close interaction between crustacean zooplankton and toxigenic , indicating that some species may play a more significant role in linking toxic cells within the food web than others.