Fig. 6

Barcharts showing the average extension rates (±SD) during and between the labeling events for four selected microstructural areas in three examined species. Results of the Wilcoxon tests indicate no statistically significant differences. a longitudinal extension rates measured during the first labeling event and subsequent recovery period in Paracentrotus lividus (spine illustrated on Fig. 2a), b extension rates of test plate in meridional direction during the first labeling event and subsequent recovery period in Paracentrotus lividus (plate illustrated on Fig. 3j), c longitudinal extension rates of regenerating spine measured during the first labeling event and subsequent recovery period in Echinometra sp. (spine illustrated on Fig. 2c), d lateral extension rates of inner cortex measured during the first labeling event and subsequent recovery period in Prionocidaris baculosa (spine illustrated on Fig. 5m)