Structural parameters for UDGs in the Hydra I cluster. Left panel: Colour-magnitude relation (CMR) for the full sample of dwarf galaxies (black points) detected in the VST Hydra I mosaic (Iodice et al. 2020) and from Misgeld et al. (2008). Red filled circles indicate the UDG candidates found by Iodice et al. (2020). The solid black line is the CMR for the Hydra I cluster early-type galaxies derived by (dashed lines indicate the 1σ scatter Misgeld et al. 2008). The magenta filled circles are the new UDGs detected in the cluster. The green point indicates UDG 32. Right panels: Structural and photometric parameters for the newly discovered UDGs (filled magenta circles) and for UDG 32 in the filament of NGC 3314A (filled green circles) as a function of the effective radius. The UDGs previously presented by Iodice et al. (2020) are marked with red circles. The UDG definition criteria, R_e ≥ 1.5 kpc and μ₀ ≥ 24 mag/arcsec² (van Dokkum et al. 2015), are shown by the dashed lines. The black points are the dwarf galaxies in Hydra I from Misgeld et al. (2008) and Iodice et al. (2020). The vertical shaded region indicates the range of uncertainty on R_e.