Relation between the Hα luminosity and the size of the identified Hα complexes in our sample (black dots), extremely luminous Hα complexes in the Antennae (blue plusses; Bastian et al. 2006), different samples of isolated giant HII regions in spirals and minor mergers (red symbols; Terlevich & Melnick 1981; Ferreiro & Pastoriza 2004; Rozas et al. 2006a), TDG candidates in CG J1720-67.8 (green diamonds; Temporin et al. 2003) and nearby dwarf amorphous (yellow crosses; Marlowe et al. 1997). None on the luminosities on the plot are corrected for internal extinction.