The Turritopsis dohrnii was first discovered in the Mediterranean Sea in the 1880s and has since left the world in awe at its remarkable skill of immortality. Life for the Turritopsis dohrnii begins as a simple planula - a type of larva - developed from a fertilised egg. The planula initially swims around, before settling on the sea floor and transforming into a group of polyps, maturing to adulthood in a matter of weeks.
A fully grown Turritopsis dohrnii is a mere 4.5mm across - so good luck ever trying to find one in its planula form. However, this species of jellyfish has a luminous red stomach, sheltered by its transparent body, with up to 90 tentacles attached to it, which may make spotting one a bit easier.
These incredible invertebrates have an astonishing, unique talent, making them mightier than any other animal out there despite their size. If they sense imminent threat or starvation, they can simply revert back to the polyp stage of their developmental process. These polyps bud after some time and produce medusae that are genetically identical to the original Turritopsis dohrnii.
So is it immortality? Or something else?
The phenomenon was first observed in the 1990s, and since then the species has been crowned “the immortal jellyfish”. There is some serious science that goes into this. A rare process known as transdifferentiation is the mechanism behind it all. This process consists of a specialised adult cell for a particular tissue having the ability to transform into a completely different type of specialised cell. Scientists are incredibly intrigued by this way of cell recycling, as its an important area of stem cell research which could benefit scientists, and help to replace cells that have been damaged by disease.
There is the question of - if all of the cells are replaced, is it still the same organism? But biology claims that the genes are the same, and therefore it is, in fact, the same organism.
