Clearance rates of bacteria-sized particles by freshwater ciliates, measured with monodisperse fluorescent latex beads.

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.