85 Fun Facts about Jellyfish [Free Fact Cards]

Have you ever seen a creature resembling a floating umbrella with trailing strings in the water? That’s a jellyfish! These fascinating sea drifters might look like simple, fun creatures, but they’re packed with surprises. They dance gracefully in the water; some even light up like fireworks. Ready to dive deep and uncover the secrets of the jellyfish world? Let’s explore more with these facts about jellyfish!

Do you love swimming in the ocean? What if you suddenly see a jellyfish that’s BIGGER than you! Some jellyfish, like the lion’s mane jellyfish, can grow super large with tentacles longer than a blue whale! But don’t worry; most jellyfish are much smaller and prefer to float around, minding their own jelly-business.

Now, here’s a glowing fact: some jellyfish can light up in the dark. These special jellyfish have something called “bioluminescence,” which lets them glow and shine underwater. It’s like they have a built-in nightlight. How cool is that?

But wait, there’s more. Even though jellyfish look soft and squishy, we need to be careful around them because many have tentacles with tiny stingers. These stingers can give a zap if touched, which is their way of catching tiny food or keeping themselves safe from bigger animals.

Are you excited to learn more about jellyfish? From their mysterious life cycles to their role in the ocean’s big picture, jellyfish have lots to share. So, let’s set sail and uncover more facts about jellyfish! Don’t forget to get your jellyfish fact cards below so you always have these facts with you no matter where you go and so you can share them with your friends! 

Want a whole collection of fact cards? Don’t forget to get your Blizzard fact cards or Oinktastic Facts About Pigs.

Best Facts about Jellyfish

1. Jellyfish are important in medical research, as they have a simple nervous system and can be used to study basic biological processes.
2. Despite their simple body design, some jellyfish have vision.
3. They Eat Where They Poop.
4. They Rarely Travel in Groups.
5. All jellyfish have nematocysts, or stinging structures, but the power of their stings can vary widely depending on the species. 

6. The most venomous jellyfish in the world is probably the box jellyfish, capable of killing an adult human in just a few minutes with a single sting.
7. The oldest known jellyfish fossil is called Eoredlichia and is estimated to be around 500 million years old.
8. They can be bioluminescent, too, which means they produce their own light!
9. The venom of different jellyfish species can range from mild to highly potent and can cause a variety of symptoms in humans, including pain, swelling, and even death in some cases.
10. The smallest are those in the genera Staurocladia and Eleutheria, which have bell disks from just 0.5 millimeters to a few millimeters in diameter. 

11. Box jellyfish are found in the waters of the Pacific and Indian Oceans and can be deadly to humans.
12. Some species of jellyfish are able to regenerate their entire body from a small piece of their original body.
13. The movement of jellyfish can be influenced by ocean currents and winds.
14. They’ve got a lot of nerve.
15. They are also an important source of food for many marine animals, including sea turtles, sunfish, and some species of birds.

16. Each box jellyfish reportedly carries enough venom to kill more than 60 humans.
17. They have very short lifespans.
18. There could be 300,000 species of jellyfish.
19. Jellyfish range from a few centimeters to over two meters in size.
20. Jellyfish are 95% water.

21. Some jellyfish species can weigh up to 440 pounds (200 kg).
22. The umbrella-shaped body of a jellyfish is called a bell.
23. Jellyfish have been around for millions of years, even before dinosaurs lived on the Earth. 
24. Box jellyfish are highly advanced.
25. They’re Adapting Well to Climate Change

26. Some jellyfish trap their prey, while others trawl.
27. They Aren’t Really Fish
28. In China, they are considered a delicacy, and are also used in Chinese medicine.
29. They don’t have brains, hearts, or lungs.
30. Some jellyfish are clear, but others are vibrant colors of pink, yellow, blue and purple.

31. Jellyfish are a type of ‘cnidarian’, which is named after the Greek word for “sea nettle”
32. Some jellyfish are able to swim continuously without stopping, while others pulse their bell in a more rhythmic manner.
33. Some species of jellyfish are able to enter a dormant state called diapause, where they can survive for extended periods of time without food or water.
34. The moon jellyfish is one of the most common jellyfish species found in coastal waters.
35. They’re Named After a Greek Monster

36. The word jellyfish has been used since 1976. It is usually applied to medusae and all similar animals including the comb jellies.
37. Stygiomedusa is a rarely seen jellyfish species.
38. Jellyfish wiped out a salmon farm in Northern Ireland.
39. The lion’s mane jellyfish has long, flowing tentacles and can be found in the waters of the North Atlantic and Arctic Oceans.
40. Jellyfish extract is sometimes used in skincare products for its anti-inflammatory and anti-aging properties.

41. Jellyfish can feel.
42. Jellyfish sting thousands of swimmers every year.
43. Jellyfish sleep.
44. Vinegar and salt may help lessen the severity of a jellyfish sting.
45. They are invertebrates and have no backbone.

46. Jellyfish are more closely related to corals and sea anemones than they are to fish.
47. Some species of jellyfish are able to survive in low oxygen environments, such as hypoxic zones in the ocean.
48. Jellyfish are often preyed upon by sea turtles, sunfish, and some species of birds.
49. Some jellyfish blooms can be harmful to humans and other marine life, causing large fish kills or even closing down beaches.
50. Jellyfish have hydrostatic skeletons.

51. Jellyfish are able to release both eggs and sperm into the water, where fertilization occurs.
52. Jellyfish are able to clone themselves by producing genetically identical offspring through asexual reproduction.
53. One species may be immortal.
54. Jellyfish are capable of swimming against the current and can move at speeds of up to 8 miles per hour.
55. A large quantity of jellyfish can tear fishing nets.

56. Jellyfish eat almost anything in the water.
57. Jellyfish have thousands of stinging cells.
58. Crystal jellyfish are totally colorless.
59. Lion’s mane jellyfish is one of the biggest known types.
60. Dead jellyfish can still sting.

61. Jellyfish have high nutritional content.
62. Jellyfish have a short lifespan, typically living only a few months to a year.
63. The bell of a jellyfish is made up of a soft, jelly-like substance called mesoglea.
64. Moon jellyfish have a mild sting and are not harmful to humans.
65. Some jellyfish can turn back their biological clock.

66. In their ecosystem, jellyfish are effective predators.
67. They are also able to move vertically in the water column, using their bell to propel themselves up and down.
68. Turritopsis dohrnii is an immortal jellyfish.
69. Jellyfish have just one opening for eating and pooping.
70. Jellyfish lifespan varies.

71. Even without eyes, jellies can still sense their environment.
72. Jellyfish blooms can consist of thousands or even millions of individuals and can have a significant impact on marine ecosystems.
73. Jellyfish kill more humans than sharks.
74. Jellyfish shoot its sting as fast as 700 nanoseconds.
75. Jellyfish don’t sting out of spite.

76. The bioluminescence of jellyfish is used for communication, camouflage, and attracting prey.
77. Cnidocytes contain a harpoon-like structure called a nematocyst, which can be fired to deliver a venomous sting.
78. Females then release fertilized eggs into the water, which develop into tiny larvae.
79. A group of jellyfish is called a “smack.”
80. Some jellyfish perform a “mating dance.”

81. Jellyfish do not intentionally attack humans, they only attack if they are touched.
82. Moon jellyfish have a translucent bell and short, frilly tentacles.
83. Box jellyfish have 24 eyes.
84. The lion’s mane jellyfish is the largest jellyfish species in the world, with some individuals reaching a diameter of over 2 meters.
85. Jellyfish can shut down nuclear power plants

Do you have even more interesting facts about jellyfish? Share them with us in the comments! Also, don’t forget to grab your free jellyfish fact cards to add to your collection! 

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