Dependences of stellar masses M_⋆ ((a), (c), (e)) and of SFR^−0.9M_⋆ ((b), (d), (f)) on the equivalent widths of the [O II] λ3727, [O III] λ5007 and Hαλ6563 emission lines, respectively, for samples of CSFGs and high-z SFGs. The solid lines in (b), (d), (f) are the maximum likelihood relations, whereas green lines in (a), (c), (e) are relations for z ∼ 1.4–3.8 SFGs (Reddy et al. 2018). Galaxies denoted in (c) and (d) by black-filled circles are z ∼ 3.5 LBGs (Holden et al. 2016), z ∼ 2 SFGs (Hagen et al. 2016), z ∼ 1.3–3.7 galaxies with high EW([O III] + Hβ) (Tang et al. 2021), z ∼ 7 SFGs with high EW([O III] + Hβ) (Endsley et al. 2021), z ∼ 6.6 SFGs with Lyα emission (Endsley et al. 2020) and z ∼ 8 galaxies (De Barros et al. 2019). Galaxies represented in (e) and (f) by black-filled circles are z ∼ 5 SFGs by Rasappu et al. (2016). The meanings of symbols for our SDSS CSFGs are the same as in Fig. 1.