A peculiar type of jellyfish native to the Carribean is believed to have a theoretically limitless life span. The turritopsis nutricula jellyfish is able to cycle from a mature adult back to an immature polyp stage a limitless number of times meaning that it appears to be impossible for it to die of old age.

The key lies in a process called transdifferentiation, where one type of cell is transformed into another type of cell. Some animals can undergo limited transdifferentiation and regenerate organs, such as salamanders, which can regrow limbs. Turritopsi nutricula, on the other hand, can regenerate its entire body over and over again. Researchers are studying the jellyfish to discover how it is able to reverse its aging process.

Native to the Caribbean oceans, Turritopsi have now been identified in waters near Spain, Italy, Japan, and the Atlantic side of Panama. Even though specimens from different locations have different numbers of tentacles (from 8 to 24), genetic tests confirm that they are of the same species.