Intersetule distances are a poor predictor of particle-retention efficiency in Diaptomus sicilis

Abstract

In contrast to published results for the copepod Acartia, the cumulative frequency distribution of intersetule distances on the 2nd maxillae of Diaptomus sicilis is a poor predictor of the experimentally determined particle-retention efficiencies of feeding. A simple model that includes intersetal retention also does not work. This may be because D. sicilis raptorially seizes particles, as well as filtering them. Certain assumptions about the hydrodynamics of the filtering process that are implicit in the intersetule-distance models may be false for Diaptomus and other calanoid copepods whose 2nd maxillae form a stationary filter chamber.