The Immortal Jellyfish: Facts & Photos
Immortal. It's a word that's tossed around a lot, and at some point almost everyone has thought about what it would mean to live forever. Perhaps immortality is meant for simpler beings, as we might over-complicate the process of "just being us forever."
In human terms, sometimes immortality would appear almost nightmarish in a way. But less complicated beings live each moment in the now anyway, and they don't have the drama that we do, or the baggage.
They float along with the tide, following the flow of life infinitely. They live for the sun shining down on them, the flow of the waters around them, the tide pushing them along indefinitely through open infinite space.
If you had the chance, would you want to live forever?
- Doesn't that appeal to you on some level?
There are beings on this Earth that do live forever, and one of those beings is the amazing immortal jellyfish (aka Turritopsis dohrnii.) Every day they live is another dance with infinity, the infinite spirit of life, and the wonderful chance of infinitude that so many wish for every day.
So if you could live forever on Earth, or at least more infinitely than we get to, what would that be like? To answer that, we need to learn more about this immortal jellyfish. How do they function, what is their secret, and how do they spend their time in infinity?
Where Immortal Jellyfish Are Found
Just like any other type of jellyfish floating in Earth's enormous oceans, the immortal jellyfishes (Turritopsis dohrnii) live interesting and beautiful lives.
Scientists believe the immortal jellyfishes originated in the Pacific Ocean. But over time they've spread through trans-Arctic migrations as well as from the ballast waters of large ships. They now populate all the world's oceans (in the temperate and tropical regions.)
And just like other types of jellyfish, they go through various stages of development before reaching their mature stage.
But unlike other types, they have the ability to revert back to earlier stages of development and start over again.
Basic Jellyfish Stages:
- Eggs are produced in the female and released into the ocean waters
- Males fertilize the eggs in the water with their sperm
- Fertilized eggs turn into planula larva which are free-swimming, flattened, ciliated, and symmetrical
- Planula larvae settle to the ocean floor and develop into polyp colonies, also known as hydroids
- Hydroids bud new tiny jellyfishes, about 1 mm in size and sporting 8 tentacles
- The tiny jellyfishes feed on plankton and begin to grow
- They become sexually mature (called a medusa) after a few weeks, where they are around 4.5 mm and sport up to 90 tentacles
What Makes This Type of Jellyfish Immortal?
Video: Immortal Jellyfish
While they reproduce and mature like many other common jellyfish types, the immortal jellyfishes (Turritopsis dohrnii) have the amazing ability to revert back to the polyp stage anywhere in their medusa stages of development.
The process, called cellular transdifferentiation, allows one type of cell to transform into another type of cell. When the immortal jellyfish reaches the hydroid, immature, maturing, or mature medusa stages, it can revert all the way back to the polyp stage at any point and start all over again. This happens either because of trauma or because it's aging and needs to renew itself again.
When reverting back to the polyp stage, first their bell and tentacles begin to deteriorate. Then they develop a protective chitin layer called a persarc and begin to break apart into separate polyps joined by stolons.
Stolons are basically connections between one polyp and another. Each of these polyps does the same thing, eventually creating a network of polyps (hydroids) where they can again bud off and move through the stages of maturity.
This ability makes immortal jellyfishes biologically immortal, having the ability to live forever in the same body/bodies. However, they are not truly immortal since they can be killed and eaten by predators. That said, scientists have identifiedTurritopsis dohrnii as the only known species of animal with the ability to physically live forever via transdifferentiation.
Amazing Facts About the Immortal Jellyfish
- They were discovered in the Mediterranean Sea in 1883 by Christian Sommer, a German marine biology student in his early 20s
- Their ability to revert to earlier stages wasn't discovered until 1996. It was first published in a paper called "Reversing The Life Cycle"
- They are thought to have originated from the Pacific Ocean
- Their ability to revert to earlier stages of development is called cellular transdifferentiation
- Transdifferentiation means that one specialized cell type can turn into a different type of specialized cell. For example, muscle cells can turn into sperm or eggs, nerve cells can turn into muscle cells, and so on (much like human stem cells)
- Though immortal jellyfishes found in various seas and oceans are genetically identical, they've adapted to their particular environments. Tropical varieties have about 30% less tentacles than those living in more temperate waters
- Turritopsis dohrnii are described by scientists as "great hitchhikers," often hitching a lift in the ballast waters of large ships and clinging to the bottoms of ships while still in the polyp stage
There’s a shocking amount of genetic similarity between jellyfish and human beings— Kevin J. Peterson, molecular paleobiologist
- For a long time the nutricula and rubra varieties of jellyfish were mistakenly referred to as the immortal jellyfish. However, transdifferentiation of nutricula or rubra was never observed
- Turritopsis dohrnii are notoriously difficult to culture in a lab environment. Because of this, very few scientists have successfully been able to study them in detail
- The immortal jellyfishes are very tiny. Fully grown, they're about the size of a pinkie fingernail
- Studying the immortal jellyfish may one day have implications for medicine, particularly in the fields of cancer research and longevity
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