In the face of danger, this species hits the reset button on life

The jellyfish Turritopsis dohrnii has a mostly normal lifecycle: Fertilized eggs become larvae, larvae become polyps, polyps spawn baby jellyfish, baby jellyfish grow up and eventually have about 100 tentacles. But then things get interesting: the species can also age backwards.

Whenever it’s hungry or stressed, T. dohrnii uses a process called ‘transdifferentiation’ to survive. Essentially, the jellyfish flips a mysterious, internal switch that restarts its cells. It morphs into a ball of tissue and stem-cells, sinks to the seafloor, and in just days becomes a genetically identical polyp—which will soon produce more jellyfish. Repeat.

Because of transdifferentiation, this “Immortal Jellyfish” can regenerate over and over again, allowing it to live indefinitely in tough environments where food is scarce. Researchers don’t yet completely understand how this adaptation works, but they now think other Cnidaria (jellyfish, corals, and sponges) might also hold the key to immortality. Indeed, living forever could be relatively common among organisms.

Only a few scientists around the world specialize in T. dohrnii, but they are working hard to uncover its secrets. If we can isolate the genes that switch on reverse aging in jellyfish, it’s possible that we could find and activate comparable genes in ourselves. Some believe that decoding The Immortal Jellyfish could help us fight cancer, master stem-cells, and, yes, maybe even live longer.