Lions Mane Jellyfish The Lion’s Mane Jellyfish lives in the depths of the ocean and is considered a large species that may vary in size from ½ inch in diameter to 8 feet, the largest type of jellyfish. They have over 100 tentacles that are divided into 8 groups that can reach up to 98 feet long or even longer. The largest recorded Lion’s mane jellyfish had tentacles that reached 120 feet long. They also vary in color, which may be purple or bright red, tan or orange, with red or yellow tentacles. It uses tentacles to grab and eat small fish and other sea creatures. The Lions Mane Jellyfish moves by contracting its muscles and propelling forward.