Ten female (mean 179 g wet mass (WM) and 25.3 cm standard length (SL) and ten male (182 g WM, 24.5 cm SL) Atlantic herring (Clupea harengus L.) were obtained from Kiel Bight (54°22'N, 010°09'E) and strip-spawned. Their offspring were subjected to feeding and growth experiments using different prey size spectra in controlled laboratory settings at different temperatures. In 4- (13°C) or 7-day (7°C) experiments, the effect of prey size on larval foraging behaviour, specific growth rate (SGR) and biochemical condition (RNA:DNA, RD) was tested. On a daily basis, the swimming behaviour and foraging activity of these larvae was recorded.