Potential effect of phytoplankton colony breakage on the calculation of zooplankton filtration rates

In laboratory experiments, mixed populations of two marine copepods (Acartia clausi and Eurytemora herdmani) when fed artificial food particles consisting of microcapsules that were either enriched with an encapsulated homogenate of naturally occurring phytoplankton or nonenriched preferentially ingested the enriched capsules. Beads or nonenriched capsules were either seldom ingested or not ingested at all. The observations demonstrate that filter-feeding in these species is a behavioral process, under sensory control, and that the copepods are able to discriminate between enriched and nonenriched food particles.