Half-light size (semi-major axis lengths) versus stellar mass for LTGs and ETGs in the Virgo and Fornax clusters. Each panel with data points shows one highlighted sub-sample (see the label in the panel), and all other galaxies are shown with grey symbols (pluses – Virgo, crosses – Fornax). Rightmost panel: running mean relations as curves. The size–mass relations are consistent for both clusters, and at low galaxy masses the sizes of LTGs and ETGs become comparable in both clusters.