Written by Michelle Reeves, Four Green Steps

In the Mediterranean Ocean, there is a jellyfish named Turritopsis nutricula that can regenerate its cells indefinitely to go back to its immature stage, and therefore live forever.

The basic life cycle of jellyfish start off with a larva, which morphs into a polyp, asexual and colonial stage, and finally moves to the medusa stage, the typical bell-shaped jellyfish. These stages are usually irreversible, but according to a study in The Biological Bulletin, Turritopsis is the exception to that rule.

These jellyfish were discovered as early as the 1880s, but its regenerating properties were not known until the mid-1990s. If an adult is threatened, injured or starving for example, it attaches itself to a surface in the warm waters, such as a rock or coral. Its cells can then undergo transdifferentiation; cells are altered and transformed into completely new cells. Muscle cells can become egg cells, nerve cells can become muscle cells, and any other change is possible.

The medusa falls apart to create a new polyp colony, and this can be done an infinite number of times, “thus escaping death and achieving potential immortality,” explains study co-author Stefano Piraino. Many genetically identical jellyfish have been found in oceans around Japan, Spain and the Atlantic side of Panama. Polyps may have gotten sucked onto the hulls of ships and carried around the globe. Though genetically identical, the jellyfish do seem to have adapted to their new environments. For example, specimens living in warm tropical waters have eight tentacles, whereas those in temperate regions have 24 or more tentacles.

However, Turritopsis can, and do, die. The cell transformation can only take place after sexual maturation, so in their early life stages, the larva and polyps can succumb to predation or disease.

Image courtesy of Creative Commons.

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