SUMMARY.1. Body growth, reproduction and survivorship ofBosmina longirostriswere monitored at four food concentrations (0.05, 0.10, 0,25 and 2.50 ing Cl−1) to examine the extent to which food concentration affects these life‐history parameters.2. Food concentration had a significant effect on growth, and most of the reproductive parameters (size and age at maturation, brood size, instar duration and egg development time). More than 60% of animals died before maturation at the lowest food concentration, although most animals survived until maturation at other food concentrations.3. Change in life‐history parameters resulted in a decrease in rate of population growth (r) from 0.310 to 0.020 day−1with decreasing food concentration, showing that this cladoceran is highly food‐limited in many lakes.4. Importance of the effect of food concentration on egg development time was emphasized in relation to analysis of natural po