Comparison of the observed main-sequence relation with the predictions of ram-pressure-stripping models for galaxies with a spin parameter λ = 0.05 and rotational velocities of 40, 70, 130, and 220 km s⁻¹. Unperturbed models are indicated with filled green squares, starvation models by the magenta lines, and ram-pressure-stripping models by the cyan lines. Different symbols for the models indicate the position of the model galaxies at a given look-back time from the beginning of the interaction. Black (red) filled circles show late-type (early-type) galaxies with a normal HI content (HI-def ≤ 0.4), and black (red) empty circles show HI-deficient (HI-def >  0.4) late-type (early-type) systems. The typical uncertainty on the data is shown in the lower left corner.