Immortal jellyfish: Does it really live forever?
The Turritopsis nutricula jellyfish has
displayed a remarkable ability to regenerate its cells in times of
crisis.
While it is often joked that cats have nine lives, a certain
species of jellyfish has been deemed “immortal” by scientists who have
observed its ability to, when in crisis, revert its cells to their
earliest form and grow anew. That means that these tiny creatures, 4 mm
to 5 mm long, potentially have infinite lives.
The creature, known scientifically as Turritopsis nutricula,
was discovered in the Mediterranean Sea in 1883, but its unique
regeneration was not known until the mid-1990s. How does the process
work? If a mature Turritopsis is threatened — injured or starving, for
example — it attaches itself to a surface in warm ocean waters and
converts into a blob. From that state, its cells undergo
transdifferentiation, in which the cells essentially transform into
different types of cells. Muscle cells can become sperm or eggs, or
nerve cells can change into muscle cells, “revealing a transformation
potential unparalleled in the animal kingdom,” according to the original study of the species published in 1996.
Since the Turritopsis’ virtual immortality was discovered, so have
swarms of genetically identical jellyfish far from their original
habitat, including in Japan, Spain and the Atlantic Ocean side of
Panama. Researchers have concluded that these multiplying creatures are
getting caught in ballast waters, water that is sucked into and pumped
out of the long distance cargo ships. Polyps also could be growing on
the ship’s hulls. Though genetically identical, these jellyfish seem to
have adapted to their new environments. For example, specimens from
swarms living in tropical waters have been found to have eight
tentacles, while those discovered in temperate regions have 24 or more
tentacles.
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Today marks the 54th birthday of the inimitable 
