The Lion's Mane jellyfish has tentacles longer than a blue whale.

The Lion's Mane jellyfish (Cyanea capillata) is a giant of the ocean found primarily in the cold waters of the Arctic, North Atlantic, and North Pacific Oceans. In 1870, a specimen washed up on the shores of Massachusetts Bay with a bell measuring 7.5 feet across and tentacles stretching 120 feet long. This record makes it significantly longer than the largest recorded blue whale, which typically reaches around 98 to 100 feet in length.The jellyfish's anatomy consists of eight clusters of tentacles, with each cluster containing up to 150 individual strands. These tentacles are coated in nematocysts, which are specialized stinging cells used to paralyze small fish, crustaceans, and even other jellyfish. Because the tentacles are so thin and fragile, they rely on the buoyancy of the seawater to maintain their incredible length without breaking.Research published in journals like 'Nature' highlights how these creatures thrive in colder temperatures, which allow for larger body sizes due to higher oxygen levels in the water. Despite their intimidating size, their lifespan is relatively short, usually lasting only about 12 months. They serve as a vital part of the marine ecosystem, providing both a predator for smaller species and a food source for leatherback sea turtles.