5 things you didn’t know about jellyfish

Jellyfish are among the most fascinating ocean creatures that the marine ecosystem has. They have evolved to survive in all parts of oceans and some can even glow in the dark. Read on to know about some of the most amazing facts about jellyfish that you probably didn’t know about.  

More than 600 million years old 
It is believed that jellyfish existed on the planet Earth even before dinosaurs, plants, or fungus. They are the world's oldest multi-organ animal, having survived all five great extinction events that we are aware of. This includes the Great Dying, often known as the Permian-Triassic extinction event, which wiped off 70% of our planet's life. Well, jellyfish have no bones and hence, no fossils. Thus, scientists have dated them by hunting for "soft fossils". Some studies have even claimed that jellyfish could even be 700 million years old!  

Hair jelly is one of the giant jellyfish varieties 
The lion's mane jellyfish or Cyanea capillata, often known as the giant jellyfish or the hair jelly, is the world's largest known jellyfish species. In fact, it was discovered washed up on the shores of Massachusetts Bay in 1870. It had a bell that was 7 feet 6 inches in diameter and tentacles that were 121.4 feet long. It was longer than a blue whale and is regarded one of the world's longest known animals! 

Made up of 98% water 
The capacity of jellyfish to blend in with the ocean can be attributed to the fact that their bodies are made up of 98% water, which is critical to their existence. Moreover, jellyfish lack blood, bones, and a heart. They do, however, have a basic neurological system with receptors that detect light, vibrations, and chemicals in the water. Jellyfish can orient and navigate in the water, thanks to these qualities plus their sense of gravity. They have no need for lungs, hearts, or blood because they absorb oxygen via their thin gelatinous skin. Some jellyfish have eyes and ‘teeth’ or tiny hair that help them with their meals.  

Jellyfish can clone themselves! 
According to scientists, a species of jellyfish, the ‘Turritopsis Dohrnii’ may be able to avoid death. This species, which can be found in the Mediterranean Sea and Japan, is capable of cellular transdifferentiation. This is an artificial process in which one mature cell is transformed into another mature cell without further division. When threatened, sick, or old, it initiates a process through which its cells return to a polyp or adolescent stage before forming a new polyp colony. This is how it creates younger replicas of itself, that when mature, will be identical to the mature adult form. Basically, jellyfish can clone themselves! Isn’t that fascinating? Well, other jellyfish species, however, are not so fortunate. Most jellyfish survive for around a year, and some barely a handful of days. 

Powerful predators 
Jellyfish have long been considered a critical prey for sea anemones, tuna, swordfish, sharks, sea turtles, and penguins. They are powerful predators, eating fish, prawns, crabs, and microscopic plants. They immobilise their victims with stinging cells in their tentacles before eating them. They have little chambers, known as nematocysts, which contain a tiny needle-like stinger. When the chamber is triggered, ocean water rushes in, causing the stinger to shoot out and the poison to be discharged into the prey. 

We bet you didn’t know the jellyfish can be this dangerous, did you?