Spectral peak absorbance (λ
) of single and double cones determined by weighting the peak absorbance of each gene by its relative expression level at each developmental stage. (a) Single and (b) double cones. Curves shown for tilapia (Oreochromis niloticus, Figure 3), Metriaclima zebra (Figure 4), M. benetos (n = 11), and Labeotropheus fuelleborni (n = 13) are taken from least squares fits to developmental data. Points for Dimidiochromis compressiceps, Tramitichromis intermedius, and M. zebra 'gold' are averages for each developmental age.