The biggest jellyfish in the world has long thought to be the lion’s mane jellyfish, based on the description of an animal caught off western North America by a geologist in 1856:
“I measured myself a specimen at Nahant, the disk of which had attained a diameter of 7.5 feet [2.3m], the tentacles extending to a length of more than 120 feet [37m].”
That’s longer than a blue whale, though today biologists aren’t entirely convinced by the story and now rate Nomura’s jellyfish as the biggest jellyfish in the world, thanks to more reliable measurements. Its tentacles are not quite as impressive as the lion’s mane jellyfish, but it can reach a massive 2m in diameter and can weigh an impressive 200kg - making it also the heaviest jellyfish in the world.
The Nomura’s jellyfish favour coastal regions and warm waters and live in the Yellow Sea and East China Sea