Seven Interesting Facts about Jellyfish

Ready to be amazed by these jelly-like ocean dwellers? Jellyfish have been floating around in our oceans for at least 500 million years, which only adds to their mystery. While there is still a lot to learn about the jellyfish, let’s dive into some fun facts about these ancient creatures.

Jellyfish are resilient.

Unlike many other marine creatures, jellyfish are doing just fine in our changing oceans. They’re thriving despite marine heat waves, ocean acidification, and overfishing, to name a few challenges. Experts expect to see changes in jellyfish populations as the climate crisis worsens, but for now, they’re hanging in there.

Jellyfish are older than dinosaurs.

These ancient creatures are tough to study since they don’t have bones, but scientists believe that jellyfish have been around for at least 500 million years and could go back even further – up to 700 million years!

Photo Credit: Ainsley Ashby

Jellyfish are invertebrates with a twist.

Jellyfish are not your average fish. In fact, they aren’t fish at all. They are invertebrates, but unlike many of their relatives, they don’t have fins, gills or even a heart. What they do have is a simple nervous system and the ability to swim by opening and closing their bells.

Jellyfish have a sense of sight.

Despite not having a heart or other seemingly necessary organs, some species of jellyfish do have eyes. The box jellyfish has 24 eyes that allow them to have a 360 degree view of their environment.

Jellyfish are immortal.

Ok, not all jellyfish are immortal, but there is one species that has a very unique trait that allows it to cheat death. When the Turritopsis nutricula is threatened, it can undergo cellular transdifferentiation to essentially become new again. Researchers are studying this unique ability in the hopes of understanding how to turn cancerous cells into noncancerous cells.

Photo Credit: jcomp on Freepik

Jellyfish are deadly.

All jellyfish have stinging structures, but their power can vary greatly depending on the species. The most venomous jellyfish is the box jellyfish, capable of killing an adult human in just a few minutes. While most aren’t nearly as dangerous, it is a good idea to give any jellyfish that crosses your path some space!

Jellyfish come in all sizes.

Some jellyfish are so tiny they’re almost invisible while others can be massive. The smallest jellyfish have bell disks just 0.5 millimeters wide, while the largest have bells that can be over six feet wide, have tentacles that span 120 feet and weigh as much as 440 pounds.

Photo Credit: bearfotos on Freepik

Jellyfish are weird, fascinating, and a little bit frightening, but that’s what makes them so intriguing. Next time you’re near the ocean, take a moment to appreciate these ancient and unique creatures that share the ocean.