Are Jellyfish Immortal?

The “immortal jellyfish” Turritopsis dohrnii (formerly known as Turritopsis nutricula) [1]

The “immortal jellyfish” Turritopsis dohrnii (formerly known as Turritopsis nutricula) [1]

A species of jelly, Turritopsis dohrnii, is able to cheat death, curling into a ball (signaling the end for most species), only to grow from its own shriveled remains into an immature juveniles once more. “ Escaping death and achieving potential immortality” writes the first scientists to describe this phenomenon [2], but is this just a neat trick, or can some species really live forever? This jelly is now known as the “immortal jelly”, and its infamy has grown with the years. But no one has published a report that this  jelly can truly withstand the test of time; in fact, only one paper has been published suggesting some jelly relatives could live forever.

Like many jelly species, members of the group Hydra have a polyp stage that reproduces asexually by budding off little clones, and people have speculated this could last for thousands of years. So Daniel E. Martínez closely watched members of one species, Hydra vulgarisfor 4 years, and in that time very few animals died [3]. Dr. Martínez suggests that since animals that start reproducing only a few days after birth, such as Hydra, tend to kick the bucket earlier than animals that wait, 4 years is a pretty long time. But does that really mean they’re immortal?

More information is needed about Hydrabut it’s not the only species people keep for decades, nor the only species that could help us understand if some jellies may last forever. So, to get to the bottom of this I polled the experts.  I sent emails to some of the top jelly aquarists asking: do polyp clone populations change over time?

Most public aquaria display jellyfish, and to do this they take advantage of the peculiar jelly life cycle.  The life of jellies is broken into two parts: the polyp-type stage, which looks like Hydra and divides asexually, and the jelly stage, which grows from polyps and gets on with the busy act of sexual reproduction. To keep the number of exhibit jellies constant, aquarists use polyps as a literal clone bank, cueing them to produce more jellies as needed.

Small green Hydra, no more than a few millimeters tall, on a stick. Source: Wikipedia

Small green Hydra, no more than a few millimeters tall, on a stick. Source: Wikipedia

And do these clone banks ever change or grow old? The answer was a unanimous “yeah, kinda.” According to aquarists at both the Monterey Bay Aquarium and the New England Aquarium, over about six years clonal populations do get “tired.” They become more fragile, don’t produce healthy jellies, and stop responding to environmental signals. Many aquarists replace their polyp stocks with new baby polyps quite regularly, so that none of this fickleness gets in the way of jelly production. The whole colony may continue to kick, but it gets more and more fragile over time. To me, this sounds a lot like aging.

When humans die it’s not because a special gene turns on that shouts: “YOUR TIME IS UP!” Rather, little things start breaking all over, cells stop dividing and those that do accumulate mutations, this is why getting older is often accompanied by all sorts of biological issues. The truth is, accumulating mutations and cell gunk isn’t something special about aging people, even clone lines of E. coli bacteria accumulate harmful cellular products over time [4]. This is just the cost of being alive. So does the “immortal jellyfish” Turritopsis dohrnii really last forever, even with all this gunk slowly working its way into its cells and genomes?

I’m not convinced. Just because you can reverse your life cycle or clone yourself doesn’t mean you’ve got a get out of jail free card for all the consequences that come with being a living thing in the first place. You are still subject to that nasty gunk build up.  Some species like Hydra vulvaris may have evolved ways to clean this gunk and beat the system, but the jury is still out on how, and for how long. While the “immortal” jellyfish Turritopsis dohrnii may be able to turn back its life cycle, it may not escape the inevitable slowing down that comes with age. In other words, while reversing your fate and escaping death for a short while may be a neat trick, it doesn’t guarantee immortality.

Work Cited

[1] Stefano Piraino, Ferdinando Boero, Brigitte Aeschbach and Volker Schmid (1996). Reversing the Life Cycle: Medusae Transforming into Polyps and Cell Transdifferentiation in Turritopsis nutricula (Cnidaria, Hydrozoa). Biological Bulletin , Vol. 190, No. 3 (Jun., 1996), pp. 302-312

[2] Stefano Piraino, Ferdinando Boero, Brigitte Aeschbach and Volker Schmid (1996). Reversing the Life Cycle: Medusae Transforming into Polyps and Cell Transdifferentiation in Turritopsis nutricula (Cnidaria, Hydrozoa)Biological Bulletin vol. 190, no. 3  pp 302-312

[3] Martínez DE (1998). Mortality patterns suggest lack of senescence in hydraExp Gerontol. vol 33 no 3 pp 217-25.

[4] Ariel B. Lindner, Richard Madden, Alice Demarez, Eric J. Stewart and François Taddei (2008). Asymmetric segregation of protein aggregates is associated with cellular aging and rejuvenationPNAS vol. 105 no. 8 pp 3076-3081 doi: 10.1073/pnas.0708931105

RR Helm (31 Posts)

I am a PhD candidate studying jellyfish development and evolution at Brown University. I've participated in numerous research expeditions, studying jellies all over the world, from Africa to the abyss. I am currently studying the beautiful mauve stinger jellies, found in the Mediterranean, and the ghostly Atlantic stinging nettles found on the US east coast.





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31 comments on “Are Jellyfish Immortal?
  1. Pingback: Are jellyfish immortal? | JellyBiologist

  2. The theoretical prediction for immortality revolves around whether a species reproduces via truly symmetrical binary fission. In this scenario it is impossible for senescent causing mutations to accumulate within a lineage. In the case of bacteria, we now realize that one pole gets the good stuff, while the other gets the bad (the bad pole undergoes replicative senescence.). So if these jellyfish could be immortal one would have demonstrate the absence of asymmetric reproduction…no evidence of that is presented.

  3. Joseph Graves Jr– Really great point! Yes, as far as I know no one has looked at the distribution of cellular components during cell division in cnidarians.

    When prepping this post, I spoke with Dr. Marc Tatar at my home institution, who researches life history and senescence, and he brought up another point (which I decided to save for its own post). If an organism becomes less able to tolerate stress over time, this is an indication of aging. From what I know, this also has not been looked at. So both symmetric division and homeostatic range need to be looked at in the group.

    Thanks for bringing this up!

    • Kris– good question. Hydra has interstitial cells (i-cells for short) that can give rise to other cell types. Presumably other species have cells similar to i-cells, but with so many species out there it’s hard to say.

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  5. On a side note, has anyone seen photos of Csiromedusa medeopolis, showing the jellyfish from the side? Google is filled with variations of one photo, but little else.

  6. Do you think we can use the DNA of this organism to combine in our DNA to produce long life?..

    • The likelihood is pretty small. They are very very different form us in many ways, and it’s still not clear if they really are immortal. However, I’m constantly surprised by innovation’s strange inspiration. You never know… in the meantime, I’m sticking to exercise and eating healthy foods ;)

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  9. Lol I love the way scientists go about these things. You see if someone was watching you in a bucket for four years you would get stressed too. So what I am trying to say is that often watching behaviour of species in a false environment is not always going to yield results. It just means you can back up your own theory because obviously you would be looking for evidence to support your own theory, or hopefully in the true tradition of science you would also be looking for the opposite. Still fascinating that as a set of species ourselves we are determined to discover any signs of immortality.

    Viva curiosity

    • Well, you gotta work with what you’ve got. These animals are nearly impossible to work with in the wild, because they clone themselves and make it difficult to keep track of who is who. None of these results are conclusive, but they do lend clues. And these clues are a nice way to start. While you think 4 years of being watched may be stressful, the opposite could also be true. Being fed regularly and living in clean water may mask signs of aging. In the same way that leaving a human in a perfectly comfortable condition will prevent any broken bones or signs of stress and fatigue. Young animals are often better able to tolerate stress by comparison to older ones. So maybe the animals find this environment really relaxing, and therefore live longer. Who knows? We have to keep plugging along just the same. Looking into what we have. The alternative is to not looking at all, and it’s not nearly as fun ;)

  10. CAN YOU LIVE FOREVER..

    For thousands of years, thinking people have wrestled with that question.

    Is there a logical, satisfying explanation—one that harmonizes with both our physical makeup and our natural desire to live forever? Millions of people would answer with a resounding yes! Why? In the Bible, they have found the most satisfying answers about human nature.

    From the outset, the Bible plainly states that humans, while having some things in common with other creatures, are fundamentally different. For example, at Genesis 1:27, we read that God created humans in his image. How so? He gave us the capacity to display love, justice, and wisdom. And as the One who lives forever, God implanted in us the desire to live forever. He “planted eternity in men’s hearts and minds,” says Ecclesiastes 3:11.—The Amplified Bible.

    Physical evidence that humans were originally designed to live much longer than we do can be seen in the power of the brain, especially in its potential to learn. The Encyclopedia of the Brain and Brain Disorders states that the long-term memory capacity of the human brain “is virtually unlimited.” Why have this capacity if it were not meant to be used? Yes, in fundamental ways, humans reflect God’s original purpose for mankind.

    http://www.jw.org/en/publications/magazines/g201308/how-long-can-you-live/

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  12. The question and desire off and for immortality. Biblical and legend tales and writings since the epic of Gilgamesh whom searched for immortality which led him to the ocean where he found a plant that only rejuvenated him a bit like a snake shedding skin as it has outgrown its old one.
    We have known that certain ocean creatures have had long life spans if not killed by predators.
    The Jelly fish actually clones it self and as it is a lot more simple that mammals are it is an easier process. It is part of the same but not exactly the same as the parent dies when it reaches adult development stage.
    However, not immortal even the Biblical accounts of the men of old have ended in some 800 to 1,000 years but not immortal. (Questioned by some studies as men and women married earlier and had children earlier so if the family had offspring at 16 and their children again at 16 by the time the original father was 80 that would have given that family five generations). The Gods of certain legends had life spans that were in the thousand year span but not eternal. The current climate, pollutants and our foods as well as what we wear, drink, breathe, may have in certain aspects shortened our natural life spans of approximately 120 years and modern medicine although claiming it helps is only a band aid solution. Genetics and changes in our DNA over the years since the Industrial Revolution have created as many if not more problems that modern Medicine claims to have solved. The introduction of the chemical agents we consumed may have impeded our brain functions and the way we are taught and educated since birth not in holistic and natural but a technological and financial focus has been designed to separate us from learning to fulfil our potential.
    We have to realise that our physical form as it is, has been designed or re engineered to fail at a certain time. Some say that we have been genetically altered after the biblical garden of Eden. The important thing we have to keep in mind is that the human soul was stated as having the capacity to be immortal not the temple which is our body. The soul has found its home in the physical form of the body. Biologically trying to extend our life span may be possible but (Scientists are working on this) if we lived 350 years our human population would have reached 4 to 5 times what it is now. Imagine the world with over 28 billion people. We already have population control Agendas (like Agenda 21 since 1992) claiming sustainability impacts.
    Our Science is not developed enough to take us off world, we can not exist under water for extended periods, the economics are controlled by the few in the minority and we are not yet ready to move in the right direction due to various reasons that we have either had created for us or have allowed to happen due to ignorance and apathy.

    • what are you saying? Everybody knows that biblic years were not 365 days.
      Even if you haven’t heard of this, at least you might be aware that Gregorian calendars is pretty modern. Going back in the years… December, for ancient Romans was the last month of the year but, as the name suggests (at least to me that I’m Italian), it was the 10th month (dieci), November was the 9th (nove), October the 8th (otto), September the 7th (sette)…. where did you find that people were living 1000 years?
      Of course, the year for Jews was not 12 months and 365 days.
      Furthermore.
      At beginning of XX century, the pollution was much less, and the food 100% natural, but the average life in Europe was 42. Now the average life is near to 80.
      If you see the average life of all famous people living in the middle age, there is evidence that little was shorter.
      Dante Alighieri, who was death at around 70, wrote around the year 1260: nel mezzo del cammin di nostra vita ….. (approximated translation: in the middle of the walk of our life ….) and it was sentenced as 30 or 35 years.

  13. Basically clones it self. Not a true definition of immortality as the original adult dies but leaves a copy of itself in an infant stage. So it recycles its lifespan cheating total death.
    However, the oceans may have held secrets to long life spans as per legendary tales such as The Epic of Gilgamesh. After years of searching he found out there was a plant in the ocean that was believed to be able to make one immortal. To his dismay he found a plant that only rejuvenated him but it did not make him immortal.
    Some of the ocean life used to grow to extremely large sizes and as such lived a very long time. There was a crab that weighed 44.6 pounds when caught and their age is determined by their weight. One pound equals 4 years. So 44.6 Lbs or pounds would have made the crab 178 years old.

  14. In response to the email I received,

    Author: Nate
    Comment:
    But is it possible to combine the DNA of jellys with human DNA to produce longer life at all?

    At this stage as far as 99% of the people know NO it is not. Personal opininon as we would not be told and if it did leak out it would have been censored and made out to be a small medical story wit the addition that it is still in its early stages and needs another 8 to 12 years of research. Just like soeme Cancer or other medical break throughs.

    If we have a look at some magazines like “TIME” and Medical Science websites we find that genetic al engineering has progressed nicely. However, for the better or worse is the moral, ethical and troubling question. Some years ago I was in a Doctors surgery waiting for a family member to get some scans. I started to read the magazines and noticed a TIME magazine. As I have been interested in Science and new developments I had to read a particular article. The scientists were cloning and combining a Goat with a Spider? Why? To produce stronger spider web from the goats milk or breasts. Spider web is flexible and stronger that steel and could be used in building and military applications. Now we are talking. The Military Industrial Complex wanted kevlar like light weight material that is bullet proof, can have electrical sensors woven in and is extremely strong they were also working on an Invisibility suit that worked on light reflection or bending principles. Alien technology people. However, there was very little mentioned about human health improvements in this article,Lets examine some of the recent news ALEX Jones website and he had a You Tube combining animal with human foetus DNA, GMO Crops and other SCIENTIFIC advancements and research. Doctors studying humans that have genetic abilities to out live normal people to find the holy grail of immortality. Yes it has all been done and is still being done. Since Adolph Hitler and Germany believed that blonde hair and blue eyed people were superior to others. Interesting how much research actually went into this and how many people were made to suffer by the medical and scientific extreme lunatics that had the Do WHAT EVER IT TAKES mentality. If we do fine the genes that can turn of the ageing process or slow it down. Who will it be tried on? Who will it be perfected on? Who will get it?
    The simple answer is NOT THE AVREAGE person and not every one. The select few that have financed and pushed the research are more that likely to be in the exclusive group along with the wealthy and important.

  15. In response to the email I received,

    Author: Nate
    Comment:
    But is it possible to combine the DNA of jellys with human DNA to produce longer life at all?

    At this stage as far as 99% of the people know NO it is not. Personal opininon as we would not be told and if it did leak out it would have been censored and made out to be a small medical story wit the addition that it is still in its early stages and needs another 8 to 12 years of research. Just like soeme Cancer or other medical break throughs.

    If we have a look at some magazines like “TIME” and Medical Science websites we find that genetic al engineering has progressed nicely. However, for the better or worse is the moral, ethical and troubling question. Some years ago I was in a Doctors surgery waiting for a family member to get some scans. I started to read the magazines and noticed a TIME magazine. As I have been interested in Science and new developments I had to read a particular article. The scientists were cloning and combining a Goat with a Spider? Why? To produce stronger spider web from the goats milk or breasts. Spider web is flexible and stronger that steel and could be used in building and military applications. Now we are talking. The Military Industrial Complex wanted kevlar like light weight material that is bullet proof, can have electrical sensors woven in and is extremely strong they were also working on an Invisibility suit that worked on light reflection or bending principles. Alien technology people. However, there was very little mentioned about human health improvements in this article,Lets examine some of the recent news ALEX Jones website and he had a You Tube combining animal with human foetus DNA.
    GMO Crops and other SCIENTIFIC advancements and research. Doctors studying humans that have genetic abilities to out live normal people to find the holy grail of immortality. Yes it has all been done and is still being done. Since Adolph Hitler and Germany believed that blonde hair and blue eyed people were superior to others. Interesting how much research actually went into this and how many people were made to suffer by the medical and scientific extreme lunatics that had the Do WHAT EVER IT TAKES mentality.
    Children were locked up and used for experiments as were prosoners, girls that were seen as Jewish or that had the wrong coloured hair, eyes and ither feathres in child rescue or parentless children in institutions were sterilised and experimented on.
    If we do find the genes that can turn of the ageing process or slow it down. Who will it be tried on? Who will it be perfected on? Who will get it?
    The simple answer is NOT THE AVREAGE person and not every one. The select few that have financed and pushed the research are more that likely to be in the exclusive group along with the wealthy and important.

  16. For that matter, why is a supplement promoted to boost brain activity made from jellyfish… which have no brains to speak of? ;)

    And I still want a glowing jellyfish protein tattoo.

    • Hey, I’ve been doing glowing jellyfish proteins tattoos on flies, do you want red or green fluorescence?

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