Turritopsis dohrnii is a so-called biologically immortal jellyfish. This means that it can not die from old age. First discovered in the Mediterranean Sea in the 1880s, researchers have found that this amazing creature has the ability to reverse its life cycle, or in other words, age backwards.

The life cycle of this jellyfish is the same as any other. It begins life as a larva, otherwise known as a planula, which is created from a fertilized egg. It then settles on the sea floor and undergoes a polyp phase, which is sort of like the cocoon of a caterpillar. After a while, the polyp releases genetically identical medusae, which are what we call jellyfish, and are fully grown in a matter of weeks.

However, while most jellyfish life for only a few months, or 2-3 years in captivity, the Turritopsis dohrnii can turn back the hands of time when in physical danger or even suffering from starvation, returning themselves to the polyp stage and emerging again as a medusae.