This is for students who would rather print out The Immortal Jellyfish, rather than complete it on the website Formative. Turn in your answers to your English teacher by September 15th. An online device will still bed needed to view the videos.  If you'd rather complete the reading online, go to Formative assignment here.

Question 2) What grade are you in?
Question 1) What is your name?


Before reading, watch the video below about  Dr. Shin Kobuta and the Immortal Jellyfish:

Turritopsis Dohrnii (The Immortal Jellyfish)

Turritopsis Dohrnii, also known as the Immortal Jellyfish (Credit: Takashi Murai, New York Times)

Turritopsis Dohrnii, also known as the Immortal Jellyfish (Credit: Takashi Murai, New York Times)

The Turritopsis Dohrnii was discovered not that long ago, by scientists in 1988. It used to be called the Turritopsis Nutricula. It is a very small jellyfish; at their largest, they grow to 4.5 mm. That's about the same size as your pinkie nail! The Immortal Jellyfish eats plankton, fish eggs and small mollusks. Like other jellyfish, the Turritopsis dohrnii moves around in the water either by floating with the current, or by opening and closing its bell to push itself forward. ( 

The Immortal Jellyfish is native to the waters of the Mediterranean Sea. However, they also can attach themselves to the bottoms of ships and are found in other areas of the world. The Immortal Jellyfish seems able to survive in every ocean in the world. Studies have shown that in recent decades, the immortal jellyfish has rapidly spread throughout the world’s oceans in what Maria Pia Miglietta, a biology professor at Notre Dame, calls “a silent invasion.” (Rich, 2012)

To learn more about how jellyfish move, watch the video below:

Question 3) How big is an Immortal Jellyfish?
  • One foot long
  • 4.5 millimeters long

How is Turritopsis Dohrnii Immortal?

It’s not, as one would expect, living for a long, long time. It turns out that this immortality has more to do with returning back to the basics. (

The Immortal Jellyfish has three main stages of life: a planula, a polyp, and then a medusa.

1) A planula is like a larvae, that is floating around in the water.
2) It sinks to the bottom of the sea-floor and grows into a polyp, which looks like a branch with tiny twigs attached.
3) Lastly, the polyp then grows into a medusa. The medusa stage is when the jellyfish grows its bell shape and dangling tentacles. (New World Encyclopedia, 2017)

The Immortal Jellyfish is immortal because of its ability to lose its maturity, and go back to the second phase of its life. When an adult T. dohrnii gets injured, sick or old, instead dying like the rest of the living creatures, it goes back to the polyp stage:

"It sinks to the bottom of the ocean floor, where its body folds in on itself — assuming the jellyfish equivalent of the fetal position. The bell reabsorbs the tentacles, and then it degenerates further until it becomes a gelatinous blob. Over the course of several days, this blob forms an outer shell. Next it shoots out stolons, which resemble roots. The stolons lengthen and become a polyp. The new polyp produces new medusas, and the process begins again." (Rich, 2012)

The jellyfish the starts the life cycle over again! A researcher named Ferdinando Boero, likened the Immortal Jellyfish to a butterfly that, instead of dying, turns back into a caterpillar. Another metaphor is a chicken that transforms into an egg, which gives birth to another chicken. (Rich, 2012)

See the infographic below to get a better understanding. Watch the jellyfish go through its life cycle!

Question 4) What is the correct order of the Immortal Jellyfish's life cycle?
  • Medusa, polyp, planula the back to medusa
  • Planula, polyp, medusa then back to polyp
Question 5) How long does transdifferentiation for an Immortal Jellyfish take?
  • 10 Minutes
  • 1 Day
  • Several Days
  • 3 Months

Does the Immortal Jellyfish really live forever?

While the Immortal Jellyfish is able to start life over again and again, there are some important differences between the Turritopsis Dohrnii and from someone being immortal.

For one thing, just because Immortal Jellyfish can start their life over again doesn't mean they can survive anything. They do not survive when they are eaten. Because they are so tiny, the Turritopsis Dohrnii get eaten a lot but larger sea creatures. They also do not survive for long when taken out of water.

Also, when an Immortal Jellyfish turns back into a polyp, it is almost like a birth of a completely new jellyfish. It is not the same jellyfish as before. Imagine if humans could do the same thing: when an adult human would become sick, old or injured, it would turn back into a teenager. However, it would not be the same person as before, or have any memories of the past; it would be a completely new version, like a clone. Immortal jellyfish can live forever, but they would not be the same jellyfish.

Question 6) Why does an Immortal Jellyfish not always live forever?
  • They can be eaten by larger animals.
  • When a jellyfish turns back into a polyp, it becomes different jellyfish than before.
  • They are allergic to seaweed.
  • Both A & B.

What are the possibilities that the Immortal Jellyfish could give us?

Shin Kubota at Kyoto University’s Seto Marine Biological Laboratory (Credit: Yoshihiko Ueda, New York Times)

Shin Kubota at Kyoto University’s Seto Marine Biological Laboratory (Credit: Yoshihiko Ueda, New York Times)

Believe it or not, humans and the Immortal Jellyfish have a lot in common. “There’s a shocking amount of genetic similarity between jellyfish and human beings,” said Kevin J. Peterson, a molecular paleobiologist. (Rich, 2012). Studying the Immortal Jellyfish may help us learn how to fight cancer, old age and death.

In Japan, there is a scientist named Shin Kubota, who studies Immortal Jellyfish for a living. He is very passionate about Turritopsis Dohrnii, and studying them to unlock the secret to immortality. “Turritopsis application for human beings is the most wonderful dream of mankind. Once we determine how the jellyfish rejuvenates itself, we should achieve very great things. My opinion is that we will evolve and become immortal ourselves.” (Rich, 2012)



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