M_H2 vs. L_B for a) spiral galaxies (T ≥ 1) and b) elliptical (circles) and S0 galaxies (triangles). L_FIR vs. L_B for c) spiral galaxies (T ≥ 1) and d) elliptical (circles) and S0 galaxies (triangles). The full green line corresponds to the bisector fit found for HCG galaxies (fit parameters are given in Table 4), while the blue dashed-dotted line corresponds to the bisector fit found for the AMIGA isolated galaxies. Both fits are done for the entire range of morphological types. The dashed black lines are offset by the standard deviation of the correlation for the isolated galaxies, which is  ± 0.35 for the M_H2 and  ± 0.4 for L_FIR. Black symbols denote detections and red symbols upper limits.