Marine Biology Commons^™

Filtering Efficiency And Feeding Mechanisms Of Daphnia Pulex On Microcystis Aeruginosa And Nannochloropsis, Elizabeth Orlowicz

Honors Theses and Capstones

The filtering and feeding rate of Daphnia pulex from the Old Durham Reservoir, Durham, NH, were measured to determine the feeding efficiency on different concentrations of non-toxic Nannochloropsis (Class Eustigmatophyceae) and toxigenic cyanobacteria Microcystis aeruginosa. Direct observations of thoracic appendage beats and post-abdominal rejections were also measured at 5*10⁵ and 10⁶ cells mL^-1 concentrations of Nannochloropsis and M. aeruginosa to examine the feeding mechanisms of the D. pulex. In the presence of increasing Nannochloropsis concentrations, the filtering rates decreased and the feeding rates increased. When exposed to M. aeruginosa, both the filtering and feeding …