The life cycle of all animals are similar, following the cycle of birth, growth, degeneration and finally death. All, except for one creature. Turritopsis dohrnii is a jellyfish that lives in the waters of the Mediterranean and Japan. It is tiny, measuring just 4.5 millimetres wide and tall, making it smaller than the nail on your little finger. But size can deceive. Turritopsis can pull off the amazing feat of reversing its life cycle, and so been dubbed the “immortal jellyfish.”

Jellyfish belong to a group called Cnidaria, which also includes sea anemones and corals. The adult jellyfish is called a medusa. When the medusa of Turritopsis is physically damaged or experiences stresses such as starvation, instead of dying it shrinks in on itself, reabsorbing its tentacles and losing the ability to swim. It then settles on the seafloor as a blob-like cyst. Then over the next 2 to 3 days, this blob develops into a new polyp – the jellyfish’s previous life stage – and after maturing, medusae would bud off. This extremely rare phenomenon has been likened to that of a butterfly which, instead of dying, transforms back into a caterpillar and then metamorphose into an adult butterfly once again. Most remarkably, Turritopsis can do this over and over again, allowing it to life forever (unless of course, it comes lunch to a predator).

Watch a video of this sublime creature here.