Relationship between the total gas-to-stellar mass (panels a), d)), the molecular-to-stellar mass (panels b), e)), and the molecular-to-atomic gas ratios (panels c), f)) and morphological type. The molecular gas mass is determined using a constant (X_CO = 2.3 × 10²⁰ cm^-2/(K km s^-1); left panels) or the H-band luminosity dependent (right panels) conversion factor of Boselli et al. (2002). Circles indicate detected galaxies, triangles upper limits. Black symbols are for late-type, red symbols for early-type HRS galaxies. For late-type systems, filled symbols indicate galaxies with a normal Hi gas content (Hi − def < 0.4), empty symbols Hi-deficient objects (Hi − def ≥ 0.4). The big symbols give the mean values and the standard deviation (in log scale) in each bin of morphological type considering only Hi detected objects with Hi − def ≤ 0.4 and CO upper limits as detections. The typical error bar on the data is given in each panel.