We’ve compiled a list of facts you probably didn’t know about these invertebrates.
Lethal encounters
That jellyfish stings are painful is no secret. But there’s one kind of jellyfish capable of killing an adult human. The box jellyfish is regarded as the world’s most venomous marine animal and swims in the Indo-Pacific and Australian waters. Anyone who gets stung can die within minutes or suffer a heart attack.
Made primarily of water
Jellyfish are comprised of 95% water. The remaining 5% of their bodies are muscle, proteins, and nerve cells.
They’re not fish
Technically, fish are vertebrates that breathe through gills. Jellyfish are invertebrates, which means they don’t have backbones. What’s more, they absorb oxygen through membranes, not gills.
Jellyfish have survived and thrived in space
In 1991, scientists sent 2000 jellyfish polyps (individual organisms) into space to study the impact of zero gravity. Not only did the jellyfish survive, but they also reproduced! Picture more than 60,000 jellyfish bred in space. Once back on earth, however, the jellyfish were unable to function.
Some never die
The Turritopsis dohrnii jellyfish transforms back into a polyp colony as it ages. These polyps, in turn, create new jellyfish with genetic similarities. Should the jellyfish suffer physical harm or injury, it can morph into a polyp on demand. And so, the reproduction cycle continues.
Jellyfish live in all waters
Jellyfish thrive anywhere – from the dark depths of the ocean floor and freezing Arctic waters to warm tropical seas. They follow the ocean currents and can live anywhere, regardless of how hot or cold the waters are.
Does urinating on a jellyfish sting relieve pain?
Unfortunately (or fortunately), this is not true. People stung by jellyfish should carefully remove tentacles with tweezers, followed by a hot water soak. Always seek medical attention no matter how minor the sting.