Symmetry in Cassiopea Images

Adult Cassiopea medusae and their polyps have been known to regenerate tissue in uncontrolled and controlled conditions; however, the regeneration capabilities of Cassiopea xamachana ephyra are largely unexplored. Here, we detail the development and regeneration of ephyrae under known laboratory conditions. Ephyrae were cut in two and then followed as they regenerated back to fully-formed individuals. We visually document all the developmental stages of the medusa leading up to the trauma and the complete regeneration process of the two halves. We show how ephyrae of Cassiopea, when cut in halves, undergo both regeneration and re-symmetrization, generating, in about two weeks, two functional smaller ephyrae with fewer rhopalia and normal behavior. We also show that regenerative capabilities diminish slowly with age of ephyra.