Three micro algae, Ankistrodesmus convolutus, Scenedesmus incrassatulus and Chlorella vulgaris, at three concentrations, were tested as diets for Moina macrocopa. Their effect on reproduction, fecundity, growth and survival was evaluated . All three algae satisfied the nutritional requirements of M. macrocopa, despite their difference in size . The best concentration, expressed in dry weight, was 5 mg 1-' for all three . Time to first reproduction was 4 days with all diets . Average time between clutches was 33 hours, and maximum number of clutches was 12 ; the highest average number of offspring per brood was 27 . The largest broods were the fourth to sixth, depending on the diet . Ephippium hatching depends on temperature, taking only 24 hours at 30 ° C and 48 hours at 27 'C . This species could be an important test organism in aquatic bioassays, and a live food in aquaculture .