Sérsic indices of all investigated objects versus apparent V-Band magnitude. Black circles: spectroscopically confirmed Virgo members, black triangles: VCC members without redshift information, red triangles: spectroscopically confirmed background objects, red circles: as background considered objects due to their large Sérsic index, black asterisks: as Virgo member considered objects due to their small Sérsic index, red crosses: objects with small Sérsic index but extreme red colour (see Sect. 5.1), dashed line: Virgo cluster membership dividing Sérsic index of 1.5 (for magnitudes fainter than m_V ≈ 18 mag).