Regression-regeneration cycle. HubotNathan H. LucasCathy PirainoStefano 2017 <p>Regression-regeneration cycle of <i>Aurelia relicta</i> polyp. (A) fully active polyp, (B) polyp in transition, (C) unattached, drifting non-feeding stage. (o), oral side. Arabic numbers indicate the progression of the process. Scale bars: 1 mm.</p>