Abstract
Monodisperse fluorescent latex particles with diameters of 0.57 and 1.04 μm have been used to measure the clearance rates of bacteria-sized particles by two ciliates from a Norwegian lake. The clearance rates by Epistylis rotans on these particles were in the range 0.23 to 1.26 μl ind-1h-1, and by Strombidium sp. 0.26 to 0.90 μl ind-1 h-1. The clearance rates varied with food level and temperature. Possibilities and limitations of the suggested method are discussed.