Fig. 2. Intensity—response electroretinograms (ERGs) of weakfish, spotted seatrout, red drum, Atlantic croaker and spot. Each species' intensity—response curve is an average of six individuals. Responses were normalized to the maximal response voltage (V_max) for each individual. Shaded boxes represent each species' dynamic range (5—95% V_max), numbers at the top indicate its breadth (in log units). Dashed vertical lines and adjacent numbers indicate K₅₀ points (illumination at 50% V_max). Open symbols and white text are results of day experiments, filled symbols and black text are of night experiments. Light intensities are in log candela m^—2. Error bars indicate ± 1 s.e.m.