Science Illustrator: Meghan Rocktopus
The immortal jellyfish starts its life cycle as a planula, a mobile larva that actively swims and settles on a surface. The settled planula will then develop into a single polyp, which will grow into a colony by asexual reproduction. Once large enough, the colony will produce and release many identical newborn jellyfish (also known as the medusa). The newborn jellyfish will become adults, release their eggs or sperm into the water column, allowing external fertilization to produce more planula. Jellyfish of T. dohrnii, when faced with unfavorable conditions (starvation, or physical damage, for example) will, instead of dying, settle onto a surface and metamorphose back into a single polyp, passing through an intermediate stage, the cyst. This process is called reverse metamorphosis. During T. dohrnii’s reverse metamorphosis, cellular transdifferentiation occurs.