The lion’s mane jellyfish, also known as the giant jellyfish or the hair jelly, is the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern Atlantic, and northern Pacific Oceans. It is common in the English Channel, Irish Sea, North Sea, and in western Scandinavian waters south to Kattegat and Øresund.
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.
Lion’s mane jellyfish have been observed below 42°N latitude for some time in the larger bays of the east coast of the United States. The lion’s mane jellyfish uses its stinging tentacles to capture, pull in, and eat prey such as fish, sea creatures, and smaller jellyfish.