We explore the behaviour of [C II] λ157.74 μm forbidden fine-structure line observed in a sample of 28 galaxies selected from ∼ 50 deg 2 of the Herschel-Astrophysical Terahertz Large Area Survey survey. The sample is restricted to galaxies with flux densities higher than S 160μm > 150 mJy and optical spectra from the Galaxy and Mass Assembly survey at 0.02 2.5×10 −3 with respect to those showing lower ratios. In particular, those with high ratios tend to have: (1) L IR