What is the largest known jellyfish species?

One of the largest recognized species of jellyfish is the lion's mane jellyfish, sometimes referred to as the giant jellyfish, arctic red jellyfish, or hair jelly. Its reach is restricted to the cold, boreal waters of the Arctic, the North Atlantic, and the Pacific Oceans of the North. It is prevalent in the English Channel, the Irish Sea, the North Sea, and south to Kattegat and "Øresund" in western Scandinavian waters.

It may also drift into the southwestern part of the Baltic Sea (where it cannot breed due to the low salinity). Similar jellyfish – which may be the same species – are known to inhabit seas near Australia and New Zealand.

In 1865, Alexander Agassiz off the coast of Massachusetts weighed the largest known specimen and had a bell with a diameter of 210 centimeters (7 feet) and tentacles about 36.6 m (120 ft) long. For some time, in the larger bays of the eastern coast of the United States, Lion's mane jellyfish were found below 42 ° N latitude.

Using its stinging tentacles, the lion's mane jellyfish captures, draws in, and eats prey such as fish, zooplankton, sea creatures, and smaller jellyfish.