Immortal Jellyfish?

There’s a particular species of jellyfish named Turritopsis dohrnii I would like to draw your attention to today. This jellyfish does a pretty neat trick, to wildly understate the case.

Like other jellyfish, T. dohrnii begin life as larvae, develop into polyps on the seafloor, and then bud off into free-swimming medusae (the familiar jellyfish form).

Unlike other jellyfish, if a Turritopsis dohrnii medusa gets injured or faces imminent death, it can do something truly incredible. Instead of dying, it reverts back to the polyp stage. This allows the jellyfish to survive virtually any undersea conditions, and it can “heal” itself by simply re-forming every cell.

This is called transdifferentiation—taking a cell and transforming it into a different type of cell—and it’s a hot topic of research in human stem cells right now. For jellyfish, it means they theoretically have the ability to repeat this cycle indefinitely, just hitting the biological reset button on occasion, watching the eons …