One of the wonderful inhabitants of the marine world is the “immortal jellyfish”, so named because of its potential for eternal life. According to scientists, some of these tiny translucent creatures were swimming long before the dinosaurs went extinct, about 66 million years ago.

It may seem like fiction, but the ability to live this many years has to do with biology – at least this interesting species. When the “immortal jellyfish” (Turritopsis dohrnii) gets old or injured, the baby can avoid death by reverting to the polyp stage. To do this, it sucks its tentacles and turns into an undifferentiated cluster of cells on the seafloor.

Thus, new adult forms can grow from these young polyps, each smaller than a human finger. And even more surprising, these mature offspring are genetically exactly the same as polyps. Its reverse life cycle has earned the hydrozoa the nickname “Jelly Benjamin Button” after Francis Scott Fitzgerald’s fictional character, who was born old and died young.

This creature was first described by scientists in 1883, but only a century later, experts accidentally discovered its endless life cycle and held it in captivity. Research since then has shown that colonies of “immortal jellyfish” found in the lab can repeat the cycle of transformation into polyps and regenerate up to 10 times within two years.

The immortal jelly is the only known species that can rejuvenate after sexual reproduction, making it “biologically immortal”.

Although the homeland of this species is thought to be the Mediterranean, it actually lives in all the world’s oceans. Despite its widespread distribution, experts still do not fully understand how this creature lived so long. In 2022, genetic research revealed more than a thousand genes associated with aging and DNA repair.

If scientists can find out what genes are present in “immortal jellyfish” compared to other species, this could shed light on the cellular mechanisms underlying their eternal life. In 2019, scientists compared the genetic activity of “immortal jellyfish” cells to adult “jellyfish” cells for the first time.

Differences were found in the functioning of some cells, suggesting that specific cells were somehow reprogrammed, for example, time was turned back. This does not mean that the “immortal jellyfish” will never die; they can still die from injury or starvation. But they are capable of preserving life like no other.