Jellyfish are among the most intimidating and intriguing creatures in the marine world, so it’s no surprise that both children and adults find them fascinating.
Below, I have prepared ten things you did not know about these wonderful and strange creatures. You may be surprised at what you don’t know about them.
1. Jellyfish are the oldest multicellular animals on the planet
Scientists have discovered jellyfish fossils in rocks believed to be more than 500 million years old. That makes them even older than dinosaurs!
2. Jellyfish have no brain
They don’t have a heart, a lung or a brain either! So how does a jellyfish live without these vital organs? Their skin is so thin that they can absorb oxygen directly through it, so they don’t need lungs. They don’t have blood, so they don’t need a heart to pump it. And they respond to changes in the environment around them by using signals from a nerve network just below the epidermis – the outer layer of the skin – which is sensitive to touch, so they don’t need a brain to process complex thoughts.
3. A jellyfish is called a Medusa
Jellyfish often look like a bell with tentacles all around. The shape of this bell is called the jellyfish because it resembles the evil Medusa from Greek mythology – a woman who offended the goddess Athena who then turned her hair into snakes and made her face so hideous that it turned people into stone. Jellyfish is also the word for jellyfish in many other languages, including Greek, Hebrew, and French.
4. Jellyfish can clone themselves
Imagine if you could split it in half and create a second version of yourself? If you cut a jellyfish in half, the jellyfish pieces can regenerate and turn into two new jellies.
5. Some jellyfish have teeth
Jellyfish have teeth. The beroid comb jellyfish has hundreds of rows of “teeth” made up of tiny hairs that can pierce, break and pull prey into the stomach.
6. The jellyfish went into space
In 1991, moonfish jellyfish traveled into space with the Columbia space shuttle so that scientists could examine how microgravity affects them. Jellyfish have multiplied in space. When they returned to Earth, scientists discovered that jellyfish born in space could not figure out how to cope with gravity.
7. Jellyfish never get tangled
Even if some jellyfish have very long tentacles, they never tangle or sting. That’s because the tentacles are very slippery and only sting other species of jellyfish.
8. Jellyfish can have super long tentacles
The lion’s mane jellyfish is the largest species of jellyfish in the world. It can have tentacles that are over 27 meters long – longer than the size of the blue whale, which is the largest mammal in the world!
9. Jellyfish groups have a really wonderful name
You might think that a flock of geese, a pack of wolves or a pack of cats sounds interesting, but groups of jellyfish have even better names. A group of jellyfish – which can include up to 300,000 specimens – is called a “flower”, “swarm” or “smack”.
10. No big deal with a jellyfish
Jellyfish are between 85% and 98% water. If they reach the beach, they will almost disappear as their water evaporates.