The jellyfish is a sea creature most people would recognize. Whether from fanciful images in picture books or from finding them washed up on the seashore. Their transparent, undulating bodies are always a point of interest
But did you know of the immortal jellyfish? Is it really immortal? How is that possible? And why would nature create a seemingly indestructible being? These are some of the questions you may have about this strange creature.
SHARE THIS IMAGE ON YOUR SITE
<a href="https://outforia.com/immortal-jellyfish/"><img style="width:100%;" src="https://outforia.com/wp-content/uploads/2022/08/immortal-jellyfish-infographic-2-683x1024.jpg"></a><br>IMMORTAL JELLYFISH <a href="https://outforia.com">Outforia</a>
The immortal jellyfish (Turritopsis dohrnii) was named after Felix Anton Dohrn. He was known as a respected naturalist in the late 1800s.
This species is also known as the Benjamin Button jellyfish. This name comes from the F. Scott Fitzgerald story, “The Curious Case of Benjamin Button.” This story is about a man that ages in reverse.
The immortal jellyfish and 50 other species are part of the family Oceaniidae. Additionally, ten other jellyfish species belong to the genus Turritopsis.
It belongs to the Anthoathecata order, where all creatures have a polyp stage. This is the stage after the larval stage where the jellyfish attach to surfaces to mature.
We’ll go over more details about the immortal jellyfish’s polyp stages later.
The immortal jellyfish is a tiny, square-shaped jellyfish. It is only about 0.18 inches (4.5 mm), with transparent bodies and bright red stomachs.
They resemble miniature jiggly ice cubes with 80 to 90 hair-like tentacles. Like other jellyfish, they begin their lives as eggs, then moonlight as planula larvae.
Planula larvae are flat, symmetrical, free-swimming larvae. They have hair-like cilia that line the outside of the larva.
In its polyp stage, the larvae attach themselves to a hard surface. They then develop a cylindrical structure. In this stage, they have digestive systems and spend most of their time feeding.
As they continue to develop, they form buds that grow off the main polyp, forming a type of colony. These buds mature into ephyra larvae, which detach and swim away from the polyp colony.
Eventually, the ephyrae enter the last stage of maturity, called medusas.
What Makes It Immortal?
Immortal jellyfish were first discovered in 1883 in the Mediterranean Sea. But their unique ability to evade death wasn’t discovered until 100 years later, by a lab accident in Italy.
Two marine biology students were observing the tiny jellyfish. They forgot to put it away when they finished for the weekend. When they returned, the medusa was gone, and in its place was a polyp.
Confused, the students deduced what seemed like an impossible explanation. The jellyfish was able to reverse its aging process to protect itself from a fatal situation.
In the mid-1990s, a skeptical professor led a workshop about jellyfish. Students observed that immortal jellyfish could reverse their lifecycle when starving or wounded. Under adverse conditions, immortal jellyfish return to the polyp stage.
It was then further studied by another student, Stefano Piraino. Through repeated experiments, he proved that jellyfish reverse into polyps when stressed. And that they could do it over and over again.
This process is called “transdifferentiation.” What’s more, this was never observed in the animal kingdom before.
This process is described as “wherein cells turn into different kinds of cells.” The fully mature medusa can return to a fixated polyp stage and start life over again. Since the polyp stage feeds on different food than the medusa stage, this is a handy skill.
There are instances when even their immortality cannot save them, though.
Suppose they are infected by a parasite or disease. If this occurs, age reversal can’t rid them of parasites or diseases, and they eventually die. And, if predators eat them, they can’t resurrect from the dead. So, even immortal jellyfish have their limits.
Are Jellyfish Alive?
While jellyfish don’t have brains, spines, etc., they are definitely living creatures. Many creatures don’t have brains, skeletons, or animal-like behaviors. However, 8 main characteristics make an animal, well, an animal.
You may also like: 15 Different Types of Jellyfish You Need to Know
Geography and Distribution
It was first discovered in the Mediterranean Sea and the Sea of Japan. But now, the immortal jellyfish can be found in oceans worldwide.
This is because they can attach themselves to ships in the polyp stage. They then hitch a ride to the farthest reaches of the seas.
They’ve also been found in ballast water: the water ships take on to maintain stability in long voyages.
Ballast water is taken in at the beginning of the journey and is often released at the end. Any creatures in the water are released as well.
Many non-native and invasive species have been transported unknowingly through ballast water. Talk about sneaky stowaways!
You may also like: How Long Do Jellyfish Live? Sweet & Simple Lives
The immortal jellyfish lives in saltwater. They’re mostly found in warm water but less frequently in colder waters. They also tend to group along the coastline.
These groups can combine with other groups to form a bloom. Because of their small size, you may not even notice these jellyfish unless they’re in bloom.
Jellyfish in tropical waters have fewer tentacles than those in temperate waters. This is likely due to each region’s feeding habits and food variations.
Diet and Food Habits
In the polyp stage, they feed on plankton and zooplankton. They expand their diet to include fish eggs, sea larvae, and other tiny sea creatures in the medusa stage.
Remember, the immortal jellyfish is teeny! So, its prey is very small as well.
Their tentacles contain toxic venom that stuns and kills their prey. However, immortal jellyfish are not active predators.
They do not hunt for food but rather eat whatever floats into their tentacles. They feed like this whether they are mobile in the medusa stage or fixed in the polyp stage.
Like most other types of jellyfish, they have an incomplete digestive tract. The food enters and exits the jellyfish through the same opening. It comes into the stomach and is broken down by enzymes. The stomach then absorbs the nutrients it needs, and the waste is expelled.
You may also like: 22 Incredible Types Of Octopus (Names, Photos & Interesting Facts)
Like other jellyfish, the immortal jellyfish has no brain, spine, or skeleton. These simple creatures appear to do nothing aside from bobbing around.
However, jellyfish have been observed to have daily sleep cycles. These sleep cycles are surprisingly similar to that of humans!
These jellyfish are not exactly social creatures. They don’t form familial bonds or have communities, per se.
However, they do often group up in areas where food is prevalent. These large groups are called blooms and may be the only way to observe these tiny creatures with the naked eye.
You may also like: What Do Jellyfish Eat? Just About Anything They Can!
Jellyfish don’t communicate with each other in the traditional sense. This is largely because they can’t speak or make noise.
Like many other deep-sea creatures, our human understanding of them is limited. It’s likely that if it did communicate, it was through chemical means. They may also use bioluminescence to “speak” to others around them.
You may also like: How Long Do Lobsters Live: Immortal Or Just Long-Lived?
How Do Jellyfish Reproduce?
Immortal jellyfish reproduce in two ways, depending on the stage of life they’re in. This is a convenient trait when your life stage changes back and forth.
The ability to reproduce in more than one way is very sustainable. It has allowed jellyfish to survive for several million years.
Unlike other species, the immortal jellyfish don’t have courting rituals or mating dances. Instead, the females spawn eggs, and the males release sperm. If the two intermingle in the ocean, the life cycle continues. It is all a supreme game of chance.
In the medusa stage, the jellyfish reproduce sexually, spawning eggs and sperm. However, this reproduction method is not as successful. This is because sperm and eggs are just released into the ocean willy-nilly.
When the jellyfish is in the polyp stage, they reproduce asexually. This means jellyfish can create new jellies from this stage without a mate. The polyps grow into ephyra larvae, which pull off and swim away to grow into medusas.
Population & Endangerment Status
It is unknown how many immortal jellyfish exist in the vast ocean waters. Scientists have only known of them for less than 150 years.
During that time, they haven’t been able to study them in their natural habitats. All the information we have about them is from captive observation.
Due to our limited knowledge of them in the wild, it’s difficult to determine how many there are. Their ideal population numbers and endangerment status is also hard to ascertain.
They do seem adaptable to varying water temperatures and environments. This adaptability may be what helps them sustain their population.
At this time, the immortal jellyfish is not considered extinct or endangered. This is because these jellyfish are immortal and have survived millions of years.
In fact, they’ve been around since before the dinosaurs. With that in mind, they’re likely to remain long after humans, too.
You may also like: 19+ Different Types Of Eels: Classification, Facts, & Photos
Threats and Predators
The immortal jellyfish has few natural predators. They are such small creatures that they’re mainly ignored in the vast expanse of the ocean.
The only thing threatening them is the imminent danger of sea temperature change. The pollution of ocean waters is another significant threat.
However, when faced with these threats, the jellyfish can reverse its life cycle. Then, all that’s left is for it to wait out the danger.
Jellyfish have an important role in the ocean biome. Their main role is to eat the tiny plankton and zooplankton. These planktons make up the deep sea’s largest population.
Moreover, they may contribute by eating tiny predators of larger sea creatures. By doing so, they are also indirectly protecting them.
Scientists are also studying the transdifferentiation process. This is to learn if it could be replicated or simulated in human cells.
This knowledge could be particularly useful in battling cancer or other terminal illnesses. Imagine the possibilities if this was ever accomplished!
Immortal Jellyfish Fun Facts
How old is the oldest immortal jellyfish?
No one knows for sure. We do know that jellyfish have existed since before the dinosaurs. With their abilities, there are likely jellyfish millions of years old today.
Can immortal jellyfish help cure diseases?
Possibly. Scientists are studying how they can trigger its transdifferentiation process. This could be helpful in cancer research and cures for diseases in the future.
How long do jellyfish live?
The average jellyfish only lives 12 to 15 months. The immortal jellyfish can live indefinitely.
How poisonous is the immortal jellyfish?
Immortal jellyfish can sting but are not poisonous or, more accurately, venomous. Its cousin, the box jelly, is an even smaller jelly with a toxic sting.
Can the immortal jellyfish be killed?
Yes. If an immortal jellyfish is eaten or infected, it will die. Even immortality has limits when it comes to predators, parasites, and diseases. Luckily, they have no natural predators and few parasites or disease threats.