Morphological color change in the Midas cichlid. A representative individual from each of the three groups (N, T and G) is shown in A. The groups are ordered along the X axis according to the melanophore density. The percentage of the scale area that is dark is shown in the box-and-whiskers plot. Plotted values represent the median (bar) and interquartile range (box) for the percentage of scale area covered by dark pigment in Normal, Transitional and Gold fish (n = 4 for each group). An ontogenetic series of a single individual is shown in B. Viable melanophores in dispersed and aggregated states are shown in C and D, respectively. Melanophores of transitional fish showing a mixture of aggregated, dispersed and dead melanophores are shown in E. Scale of a gold fish completely lacking melanophores (F). (B). A decrease in the number of melanophores can be readily noted both from the total amount of dark pigment in the body (A) or individual scales (D-F).