Stellar (top) and gas (bottom) mass-weighted average metallicity, Z_stellar and Z_gas, respectively, in dependence of the stellar mass, M_stellar, and gas mass, M_gas. The stellar and gas mass-weighted average metallicities, Z_stellar and Z_gas, are defined by Eq. (B.1). Blue bins are DMC stellar objects, green dots are DM-rich DGs (M_dm/M_baryonic ≥ 1), magenta squares are DM-poor DGs (M_dm/M_baryonic <  1), and red triangles are TDGCs of sample A.