Immortal Jellyfish
Known as the Turritopsis dohrnii species by scientists, the species is commonly referred to by everyone else as the “Immortal Jellyfish.” However, it should be known that they are not technically immortal based on what one would normally associate with the term. Rather, they are “biologically” immortal. This means that from a physical standpoint, they will not die from “natural causes” essentially. Therefore, they can die if perhaps a predator decides to eat them. They can also die from severe injuries, yet this is not as common. Biologically, they are able to be immortal in some really interesting ways.
If they are exposed to anything such as environmental stress, sickness, old age, or even physical assault…they can revert back to the polyp stage of life. In fact, the species even forms an entirely new polyp colony. All of this is thanks to transdifferentiation, which alters the differentiated state of cells and effectively transforms them into new cell types. From a theoretical standpoint, this can go on forever. Due to the species changing so well, scientists have no idea how to age any of these jellyfish for certain. Making them some of the most mysterious animals in the wild today.