Daphnia and ciliates: who is the prey?

The fortuitous observation of a Daphnia infested by Gymnostomatida led us to hypothesize that egg predation by ciliates could be an important mechanism regulating cladoceran population dynamics. In light of this hypothesis we reanalysed data on the dynamics of Daphnia eggs and of one Gymnostomatida species from Lago Maggiore (1996). This communication is mainly a plea to examine data where both cladocerans and Gymnostomatida were collected, to verify if the occurrence of this yet undescribed eggvoricity is widespread. Further research is needed to investigate the ecological significance of this phenomenon.