02/02/2026
Who wants to live forever?
The Immortal jellyfish, that’s who!
The immortal jellyfish, known as Turritopsis dohrnii, has the ability to reverse age and theoretically live an eternal life. Because of its ability to regrow its cells, it could theoretically escape death over and over again.
The life cycle of the immortal jellyfish is what makes it extraordinary. Like most jellyfish species, it begins life as a larva, which settles on a surface and grows into a polyp, which is a blob-like cyst. This is the stage where the jellyfish is still attached to the sea floor.
This polyp then transforms into a medusa, which is the free-swimming stage of an adult jellyfish. And the medusa is generally the final stage of a typical jellyfish's life before it dies.
But immortal jellyfish — when faced with stress, injury or starvation — have the ability to revert back into a polyp. Through a process known as transdifferentiation, they are essentially resetting their biological clocks to cheat death.
The reincarnated polyp eventually produces new medusae that are genetically identical to the previous version of the immortal jellyfish. This process is called transdifferentiation, where mature cells transform back into stem-like cells or polyp cells, allowing for regeneration of a whole new body.
The immortal jellyfish can repeat this life cycle reversal indefinitely, which helps it survive in changing environments and unfavorable conditions.
In reality, because the immortal jellyfish is tiny and easily preyed upon, the immortal jellyfish is frequently eaten by fish, sea turtles, slugs and other sea creatures — so they are perfectly capable of dying.
But even if they do regenerate forever, this begs a question of science fiction and philosophy: If all of an immortal jellyfish's cells are replaced but perfectly duplicated, is it technically the same jellyfish?
Scientists have been studying the immortal jellyfish to see if they can learn anything about extending the lives of people.
Though human beings may not be able to magically revert to a youthful state in the same way, the research may give new insights into stem cell research, as scientists discover new ways to replace cells that have been damaged by disease.