Regeneration and Musculature in Halved Cassiopea xamachana Ephyrae

Adult Cassiopea medusae and their polyps have been known to regenerate tissue in uncontrolled and controlled conditions; however, the regeneration capabilities of Cassiopea xamachana ephyrae 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 complete 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 C. xamachana, when cut in halves, undergo both regeneration and re-symmetrization, generating, in about 2 weeks, two functional smaller ephyrae with fewer rhopalia and normal behavior. We also show that regeneration is slower in older ephyra.