Feeding of Brachionus calyciflorus on Tetrahymena pyriformis using

This study was carried out in the wider frame of the quatitative evaluation of trophic transfers occurring in large rivers between metozooplankton and protozooplankton. Since the rotifer B. calyciflorus is dominant in the river Meuse (Belgium) its feeding on the widespread ciliate T. pyriformis was studied. Grazing rates were either determined through monitoring of cell number variations in experimental media or through use of fluorescently labeled ciliates. The labeling procedure consisted in allowing the ciliates to ingest fluorescent microspheres (0.5 µm in diameter) for short period of time; since number of ingested fluorescent spheres are very stable