Projected phase-space diagram of the cluster members in Hydra I inside the VST mosaic, i.e. ∼0.4 R_vir. The giants and brightest galaxies (m_B < 16 mag) and the dwarf galaxy population by Christlein & Zabludoff (2003) are marked with filled black circles and blue triangles, respectively. The newly confirmed UDGs in the cluster by Iodice et al. (2023) are marked with red asterisks. The solid black line corresponds to the cluster escape velocity. The shaded regions of the diagram indicate the infall times as predicted by Rhee et al. (2017), and reported in the legend on the right. The brightest members of the sub-groups of galaxies identified in the clusters (i.e. north group, SE group, and HCG48 group) are also marked with coloured circles, as listed on the right side of the figure.