[en] Adult Daphnia magna were starved and monitored for lipid content and brood production. Mean lipid index values declined for 72 hours to less than 50% of 24 hour values. Number of hatched young was inversely related to lipid storage and ovary production. Uptake kinetics of ¹⁴C-labelled quinoline was compared between two daphnid test groups with mean lipid scores of 5.4 and 2.8, respectively. Total ¹⁴C counts were significantly higher for the high lipid group at 8 hour. Our studies indicated that lipid reserves of daphnid test populations can be routinely monitored as an indicator of environmental stress