We tend to associate being immortal as some form of science fiction. Like Dracula and The Doctor from Doctor Who.
Pretty much something that’s actually not real.
But as it turns out, there is an animal that can live forever. This animal is known as the Turritopsis dohrnii, or the immortal jellyfish.
![File:Turritopsis nutricula Kamo.jpg File:Turritopsis nutricula Kamo.jpg](https://substackcdn.com/image/fetch/w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2F5fcd4b17-7462-4fab-be20-11da717f3e28_800x600.jpeg)
The immortal jellyfish is a small jellyfish found around the world in temperate to tropic waters. And it’s famous of course, for its regenerative abilities.
The immortal jellyfish starts off their live as a free-swimming larva looking for a rock or hard substance to attach itself to. Once the larvae settle down, it metamorphoses into a tiny polyp.
The polyp then clones itself, creating a colony of polyps attached to the sea floor. When the conditions are right, the polyps bloom and baby jellyfish bubs off from the polyp.
Eventually these baby jellyfish develop into adult jellyfish known as medusa.
![File:PSM V33 D765 Turritopsis.jpg File:PSM V33 D765 Turritopsis.jpg](https://substackcdn.com/image/fetch/w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fsubstack-post-media.s3.amazonaws.com%2Fpublic%2Fimages%2Fdf6a8610-60c4-4820-9c41-cd8376e7290e_441x599.jpeg)
Pretty interesting, isn’t it?
But this is where it gets even more interesting.
When the medusa experiences physiological stress such as starvation or injuries from predators, rather than dying, the medusa shrinks in on itself. The medusa reabsorbs its tentacles, losing its ability to swim. It then sinks to the seafloor, forming some kind of blob.
Then in the next 24 - 36hrs, this blob develops in a polyp. And the whole process repeats.
The poly develops into a colony, and eventually baby jellyfish bub off, forming more medusas.
This extremely rare process is known as transdifferentiation. And it technically can go on forever, making the jellyfish immortal.
But the immortal jellyfish is not the only jellyfish that can do this.
A few species of jellyfish such as the moon jellyfish also have these immortal abilities.
While transdifferentiation does mean that the immortal jellyfish can live forever, in nature, the jellyfish mostly succumbs to disease or predation in their medusa stage without reverting to polyp form.
Regardless, given their immortality abilities, it’s not surprise that the jellyfish is the target of pharmaceutical and anti-aging research.
Who knows, once we unlock the jellyfish’s secret, maybe we can become immortal ourselves.
Do they keep their memories from previous medusas or do they factory reset each time