Jellyfish
Are some jellyfish immortal?
Some jellyfish, such as Turritopsis dohrnii, have the ability to regenerate.
- 1mn read

The jellyfish is a very ancient marine animal that has been around for 600 million years and is still fairly primitive, having no heart, lungs or brain.
But despite this, jellyfish can be immortal!
The Turritopsis dohrnii jellyfish has the unique ability to reverse the ageing process, even after reaching sexual maturity.
This small jellyfish, measuring just one centimetre in diameter, can reverse its life cycle and pass from the jellyfish stage to the polyp stage in the event of a threat or environmental stress. And this process can be repeated indefinitely.
This rare characteristic makes it "theoretically immortal", at least in biological terms.
The study of its genome revealed its ability to repair and protect its DNA and to maintain a high number of stem cells that can renew any other cell.
These capabilities are of interest to biologists and geneticists, inspiring research into stem cells to repair human tissue and halt the ageing process.
So will we all be immortal tomorrow?