The search may be over, the goal of immortality attained – by a hydrozoan jellyfish. The Turritopsis nutricula species of jellyfish may be the only animal in the world to have truly discovered the fountain of youth.
Jellyfish usually die after propagating but Turritopsis reverts to a sexually immature stage after reaching adulthood and is capable of rejuvenating itself.
The 4-5mm diameter creature, technically known as a hydrozoan, is the only known animal that is capable of reverting to its juvenile polyp state.
Since it is capable of cycling from a mature adult stage to an immature polyp stage and back again. Theoretically, this cycle can repeat indefinitely, rendering it potentially immortal. Scientists say the hydrozoan jellyfish is the only known animal that can repeatedly turn back the hands of time and revert to its polyp state (its first stage of life).
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. The jellyfish and its reversal of the ageing process is now the focus of research by marine biologists and geneticists. It is thought to achieve the feat through the cell development process of transdifferentiation, in which cells transform from one type to another.
The switching of cell roles is usually seen only when parts of an organ regenerate. However, it appears to occur normally in the Turritopsis life cycle.
Because they are able to bypass death, the number of individuals is spiking. They’re now found in oceans around the globe rather than just in their native Caribbean waters. “We are looking at a worldwide silent invasion,” says Dr. Maria Miglietta of the Smithsonian Tropical Marine Institute.