EVALUATION OF A FLUORESCENT MICROPARTICLE TECHNIQUE FOR MEASURING FILTERING RATES OF DAPHNIA

The paper demonstrates the applicability of fluorescent microparticles (FMP) for the determination of cladoceran feeding rates. For this pur pose we examined the relation between filtering rate, ingestion rate, gut passage time and body length of Daphnia pulex at different food co ncentrations in laboratory experiments, and diurnal changes of filteri ng rates of Daphnia longispina in in situ experiments, using FMPs as t racer particles. Good agreement of our results with published data bas ed on cell counts and radiotracer methods proves the suitability of th e FMP-method. Potentials and limitations of the method are discussed.