Comparison of the distributions of the CALIFA mother sample (empty bars) and the 107 galaxies analyzed here (filled bars). From bottom up, and from left to right, we show the distributions of: u − r color, the ratio between the semi-minor and semi-major axis, the absolute magnitude, the Petrosian 50% radius, , and the concentration index (measured at the SDSS r band). The histograms are normalized to form a probability density, i.e. each bar scales with the ratio of the number of galaxies in each bin and the total number of galaxies × bin width, so that we can directly compare the two distributions. The upper-right panel shows the CMD where galaxies of the mother sample are the gray points and the 107 galaxies analyzed here are marked as black points.