Particle size selectivity of two marine ciliates - Balanion comatum Wulff and Strombidium sp.

Food selectivity of marine ciliates Balanion comatum Wulff and Strombidium sp. (mean size of cell 19 [mi]m) were studied in situ during incubation with wheat starch particles as a surrogate food. Range of particles ingested by Balanion comatum was 1.25-7.50 [mi]m with preference for 3.75 [mi]m particles (statistically significant result). Strombidium sp. engulfed particles ranging from 1.25 [mi]m to 5.00 [mi]m also with preference for 3.75 [mi]m particles. In the Baltic Sea size range of particles preferred by both ciliates is dominated by nanoflagellates.