When it comes to jellyfish, there are a few things that everyone probably knows. Most people know that they’re gelatinous looking creatures and that they sting, but beyond that, jellyfish are quite a mystery. In fact, jellyfish are one of the oldest creatures on the planet. Here are some interesting facts that you probably never knew about these gooey creatures of the sea.
Jellyfish are old. In fact, they’re older than dinosaurs by hundreds of millions of years. Experts believe that jellyfish are at least half a billion years old! Some estimates put the first jellyfish species as 700 million years old or even older. That’s more than three times the age of dinosaurs.
“Jelly-zooplankton” would be more accurate.
The truth is, jellyfish aren’t actually “fish” at all. They’re invertebrates that scientists call “gelatinous zooplankton.”
Their biological makeup is pretty wild.
Jellyfish have no heart or brain, only a basic set of nerves that run through their body. Their bodies are so thin that diffusion alone can completely oxygenate them. That’s also because their bodies are made up of 98% water. That’s why they seem to just float effortlessly with the ocean’s currents and practically disappear a few hours after washing ashore. Their bodies literally evaporate into thin air!
At least one species might live forever.
One species of jellyfish, called Turritopsis nutricula, is capable of completely regenerating new cells in a process called cellular transdifferation. Essentially, that means if it’s threatened, it just starts its existence all over again.
Some do have eyes.
Even though they don’t have a heart or brain, some jellyfish do have eyes. In fact, the box jellyfish has 24 eyes in total. Some scientists believe that this makes the box jellyfish one of the few animals on earth that can see 360 degrees around it at any given time.
They’re one of the deadliest creatures in the world.
Staring at a gently bobbing jellyfish might not conjure up any images of danger, but the truth is that the jellyfish is among the world’s deadliest animals. The aforementioned box jellyfish is so venomous that a single sting is enough to kill a human in minutes. And each individual animal has enough venom to kill 60 human beings. To top it off, the stings also generate some of the most excruciating pain of any animal on the planet, too.