Consumption rate and feeding success of newly hatched paralarvae of the cephalopod Octopus vulgaris preying on Artemia larvae were investigated in relation to visual conditions and prey density. Each paralarva was tested individually using a small-scale experimental setup; consumption over one day was measured at 20°C. A factorial experiment was designed to investigate the effects on the consumption rate of two predictor variables: illumination/background (three levels: 7.5 Wm−2 white light + white background, 7.5 Wm−2 white light + blue background, darkness) and prey density (four levels: 2.35, 4.70, 9.40 and 14.10 Artemia metanauplii ml−1). Consumption rate varied significantly between different conditions of illumination and prey density. Light enhanced consumption rate, but different backgrounds yielded similar rates. The maximal consumption rate under illumination was close to 16 Artemia paralarva−1 day−1, and it was around 5 Artemia paralarva−1 day−1 for assays in darkness. The predatory efficiency, measured as the proportion of prey consumed, was significantly affected by prey density, pointing to a type III functional response. The number of nonfeeding paralarvae was significantly higher in darkness and at low prey density.