15 Interesting Jellyfish Facts That Are Fascinating

Jellyfish are, without any doubt, one of the weirdest animals on planet Earth. They look and act like aliens, and if humans never discovered them earlier, we might have thought they came from another civilization. 

Jellyfish have a strange reputation among scientists and enthusiasts because of the various processes they undergo that no normal animal should experience; these biological activities would irk many people out and could even confuse anyone unfamiliar with jellyfish. 

So, in today’s article, we’ll dive into the weirdness and quirkiness of jellyfish with 15 fun facts about them. So, get your tentacles ready and hop on the ride.

Flash Facts

They Can Clone Themselves 

That’s right, you aren’t in a sci-fi movie where there are interplanetary lasers and warships. Jellyfish can clone themselves naturally. They do this in what we call their teenage state, known as polyp. 

When a polyp reaches a particular maturity, it can begin splitting segments of its body off; this results in the development of new jellyfish that live distinctly from the original. The process is called strobilation. What a peculiar way to reproduce. Imagine if your fingers could create an entirely new human.

They Have No Brains

Just when you thought we’d go easy on you, here’s another bombshell. Jellyfish are one of the few animals to have no brains. Yes, they perform every single task, like hunting for prey and reproduction, through feeling the world around them and responding accordingly with the help of a decentralized nervous system.

Jellyfish Have No Heart

Did you think having brains was the least of a jellyfish’s problems? How about having no heart? These animals keep looking more like aliens with their odd anatomy. They don’t need a heart and have more efficient ways to get and store oxygen. The most prominent is their epidermis, which absorbs oxygen and ensures it spreads through their body.

They Have No Bones

Wouldn’t it be weird if we named an animal jellyfish, and it had bones? Good thing no one thought about that. Because they already have an epidermis that absorbs oxygen and helps maintain their structural integrity, they never developed bones since they came into existence.

They Have Been Around For Up To 700 Million Years

Imagine a creature that never had bones for 700 million years. Well, now you’ve met the jellyfish. According to scientists, these animals existed as far back as 700 million years ago. 

Fossil evidence shows they were already on Earth about 505 million years ago; this means they started existing more than 250 million years before the dinosaurs.

How many catastrophes do you think they survived? Guess in the comments.

Jellyfish Are 95% Water

Don’t tell me you thought it was jelly. Jellyfish are 95% water. What’s the other 5% made of, you might ask. Well, muscles, nerve cells, and proteins that enable them to respond to stimuli, move, eat, and reproduce.

The Biggest

Though they have some of the weirdest anatomy, like having no brains, hearts, and bones, jellyfish can get even more bizarre with humongous sizes that defy logic. The lion’s mane jellyfish is the largest known species.

It can reach a whopping length of 210 centimeters (7 feet) and with tentacles three times longer than a school bus at 36 meters (120 feet).

The Smallest

You’ve learned about the behemoth, but do you know that they can be almost microscopic? That’s right, the Irukandji jellyfish is the smallest known species.

Its bell disk can be as small as 0.5 millimeters and is only visible with a microscope or lens. Another unusual thing about the Irukandji jellyfish is their remarkable cloning ability through fission.

It’s only fair for a microscopic organism to have atomic powers.

Some Can Have 24 Eyes

Imagine having 24 eyes and no brain. That doesn’t sound possible because how would a living organism control its response to light if there’s no brain? Luckily, there’s one organism in that situation. 

Box jellyfish are famous for their unique anatomy. They have 24 eyes that work in unison. Two can detect colors, while four can process visual information in parallel; this gives them a full 360-degree vision.  How do they process visual information without a brain? They do so with a network of neurons called rhopalia.

They Are Efficient Swimmers

Imagine having no brain and still outperforming creatures with large fins at swimming. That’s how good jellyfish are at sea. They are so efficient that they use about 50% less energy than most sea creatures like whales, sharks, and dolphins.

With their efficiency, they travel farther than other creatures, about 80% more, on the same energy use. That’s amazing.

Some May Be Immortal

Just when you thought it couldn’t get weirder, it does. Some jellyfish, like the Turritopsis dohrnii, are virtually immortal. They can live forever because of their unique ability to reverse their developmental process. 

The immortal jellyfish can devolve from an adult to a lower sexually immature stage, and it can do this for as long as it wants. The only causes of death it can face are predators, disease, and accidents.

Wow, imagine if people could revert to being teenagers again. We doubt many of you would want to return to that stage.

Humans Eat Them

When you thought humans couldn’t possibly find a way to add jellyfish into their diet, they’d utterly surprise you. They are delicacies in some parts of the world, like Asia and the United States. It makes you wonder what the first person who caught, cooked, and ate one was thinking.

They Can Be Poisonous

Most jellyfish can unleash a painful sting on anyone close enough; this is even scarier because their tentacles can be virtually invincible inside the water.

However, it can be worse as some, particularly box jellyfish, are so dangerous that they are ranked the number one most venomous animals in the ocean. So, it’s best to read signs warning about dangerous ones and avoid them.

They Can Have Humongous Blooms

Jellyfish blooms are a sudden spike in population due to immensely favorable conditions; these blooms can severely impact the environment. Some blooms in Japan can have up to 500 million of the creatures, each reaching 6.5 feet.

A Group Name

If you’ve ever been curious about jellyfish, you must have wondered what a group is collectively called. Besides bloom, the terms swarm, smuck, and smack can refer to a group.

Conclusion

We hope you enjoyed reading our 15 fun facts about jellyfish. Don’t forget to leave us a comment and share. You can also check out our Axolotl Facts article or search our Facts Database.