The dynamics of zooplankton herbivores in Lake Valencia, Venezuela, were studied over a 5—yr interval. Lake Valencia is a large, warm—monomictic, eutrophic lake. Copepods were the dominant group; rotifers were more abundant than the cladocerans, which were not present in all years. Variation between years in herbivore biomass bore no statistical relationship to patterns in algal biomass. The average annual dry mass production of the herbivores was high (7.0 mg · L—1 · d—1), but less than expected given the high primary productivity of the lake. The annual ratios of production to biomass for individual species were well below the maxima expected for steady growth, and thus imply growth suppression. Feeding capacity of Chaoborus, the principal primary carnivore, exceeded herbivore production for 66% of the sampling dates. Annual overturn broke the coupling between predator and prey by causing extensive mortality in both herbivores and carnivores; herbivores recovered from this suppression more rapidly than carnivores. Herbivores followed three basic strategies for coexistence with their predators in Lake Valencia: (1) two Brachionus species were able to match predation losses by reproductive output; (2) the copepods, which experienced intense predation pressure as adults, were able to sustain the high losses because the adult stage was subsidized by recruitment from earlier, less vulnerable developmental stages; (3) Keratella and the cladocerans were opportunistic in that they became abundant only in response to a decline in the predator population. The opportunistic species were most abundant during the mixing season, which was the period of minimum abundance for Chaoborus. Predation strongly influenced the herbivore populations, but population data indicate that inadequate food resources also played a role. Growth suppression was the result of qualitative rather than quantitative inadequacy in the algal food base. The intensity of control by the two factors was strongly affected by abiotic factors associated with mixing events. Partial mixing provided brief respite from growth suppression for certain species (typically rotifers), but did not alter predation pressure. Annual overturn resulted in improvement of food quality, but because mortality of herbivores coincided with relaxation of predation, the herbivores were delayed in exploiting qualitative improvements in the food resources. Periods of simultaneous release from growth suppression and predation were infrequent and brief. Herbivores were thus controlled simultaneously by predation and quality of food resource.