Intrazooplankton Predation by Mesocyclops edax at Natural Prey Densities1

Abstract

Predation by Mesocyclops edax on Diaptomus floridanus was studied. Selective predation on Diaptomus copepodites rather than cladocerans was strong. Observed feeding rates on Diaptomus copepodites at lake densities varied from 0.07–1.30 prey per predator per day. Maximum estimates of in situ predation rate for two lakes with similar species composition were 1 and 6% of the standing crop of copepodites per day. The highly selective predation and the rate of predation are considered sufficient to greatly influence the species and size composition of the herbivores.