12 Reasons the Lion's Mane Jellyfish Is One of the Ocean's Weirdest Creatures

Why are humans interested in going into outer space when the weirdest things already exist on earth? Specifically, under the sea. You’ve heard of jellyfish before, but you’re about to meet your new favorite jellyfish - the lion’s mane jellyfish. Not only is it massive, but it looks like something that would befriend a child in a Disney movie about the importance of friendship.

People have known about this incredible sea creature for years, one famous author even wrote them into one of his short stories as a villain. But people don’t really think about lion’s mane jellyfish until they wash up on the shore and freak everyone out. These facts about lion's mane jellyfish are going to take you on a deep dive into an ocean of information.


  • A Lion's Mane Jellyfish Is SO Big

    A Lion's Mane Jellyfish Is SO Big
    Photo: nurpax / flickr / CC-BY 2.0

    HOW BIG IS IT? Well, a belly of these particular jellyfish grow to be eight feet wide, and its tentacles reach out to be 120 feet long. Impressive. That's longer than the entire length of a blue whale, one of the largest creatures in the ocean

  • Très European

    Très European
    Photo: Maritime Aquarium at Norwalk / flickr / CC-BY-ND 2.0

    The lion's mane jellyfish isn't something you're going to run into while you're snorkeling in the Bahamas, instead you have to find yourself in the chilly waters of the Arctic, northern Atlantic, and northern Pacific Oceans. So throw on your water goggles and dive into the English Channel or the Scandinavian waters of Kattegat and Øresund. 

  • They've Got Some Very Grabby Tentacles

    They've Got Some Very Grabby Tentacles
    Photo: opacity / flickr / CC-BY-NC-ND 2.0

    If you've got tentacles that reach out to 120 feet, then it's likely you'll use them for something. The lion's mane jellyfish can reach out with each individual tentacle - of which it has many - and grab its prey for a nice little snack. But what's an LMJ snacking on? This underwater dynamo has a diet of small fish, sea creatures, and other jelly fish. 

  • Their Greatest Enemy Is a Big Leathery Turtle

    Their Greatest Enemy Is a Big Leathery Turtle
    Photo: Travis S. / flickr / CC-BY-NC 2.0

    Every animal needs a nemesis, and the lion's mane jellyfish has a mortal enemy in the leatherback sea turtle that feeds almost exclusively on jelly. Obviously not just any jelly, specifically they need to eat jellyfish. Because the lion's mane isn't very dense the turtles have to eat gobs of it. Lion's mane jellyfish have no hope of outrunning a leatherback turtle, all the turtles have to do is find the balloon like jellyfish and slurp them up. 

  • Let's Talk About Sex (Jelly) Baby

    Let's Talk About Sex (Jelly) Baby
    Photo: lyng883 / flickr / CC-BY 2.0

    Lion's mane jellyfish have pushed aside the entire need for a mate to help with procreation. This mammoth of a sea creature carries both eggs and sperm. Once an egg is fertilized, the female of the species carries it on its tentacles until they develop into larvae. At maturation the larvae are deposited onto a hard surface and become polyps, then the polyps transform into stacks of smaller creatures - which is insane - and grow into a living jellyfish. That's incredibly unsettling.  

  • One of These Bad Boys Might Have Stung 150 People

    One of These Bad Boys Might Have Stung 150 People
    Photo: Derek Keats / flickr / CC-BY 2.0

    First of all, if you're going to be stung by a jellyfish it should be a lion's mane jellyfish - they might be big but they don't pack much of a bite. Although if you get tangled up in multiple tentacles, you should probably seek immediate medical attention. On July 21, 2010, more than 150 people were stung by the remains of a lion's mane jellyfish that had broken apart off the coast of Rye, NH. Its tentacles were still full of venom and filled the surf.