The effects of different illumination levels on Zooplankton abundance and feeding periodicity, growth and survival of hatchery-produced Asian sea bass, Lates calcarifer, fry in illuminated floating net cages were determined in a 35-day experiment. Zooplankton abundance (consisting mainly of copepods at 64–78% of total abundance in all cages) was highest in cages illuminated at 180 lx (mean: 124 individuals l⁻¹) and at 300 lx (mean: 405 individuals l⁻¹) and peaked at 0400. High prey densities subsequently resulted in increased fish feeding as evidenced by the greatest number of prey (mean: 416–462 individuals fish⁻¹) found in their guts between 0400 and 0800. Feeding incidence (range: 84–89%) was generally higher among fish held in illuminated cages than those reared in dark cages (67%). Low feeding of fish held in dark cages eventually led to starvation and mass mortality. The present results indicate that a light intensity of at least 300 lx attracts the highest number of zooplankton and promotes the best weight specific growth rate (10% day⁻¹) and survival (40%) in sea bass juveniles reared in illuminated nursery cages.