Jellyfish always much greater than the Lion's Mane, whose bell diameter can reach . The rarely encountered deep-sea jellyfish "Stygiomedusa gigantea" is another candidate for "largest jellyfish", with its thick, massive bell up to wide, and four thick, "strap-like" oral arms extending up to in length, very different from the typical fine, threadlike tentacles that rim the umbrella of more-typical-looking jellyfish, including the Lion's Mane. Jellyfish have a complex life cycle which includes both sexual and asexual phases, with the medusa being the sexual stage in most instances. Sperm fertilize eggs, which develop into larval planulae, become polyps, bud into ephyrae
Blue jellyfish a similar way to the life cycle of the moon jellyfish. Blue jellyfish Cyanea lamarckii, also known as the blue jellyfish or bluefire jellyfish, is a species of jellyfish in the family Cyaneidae. Populations in the western Pacific around Japan are sometimes distinguished as "Cyanea nozakii" or "Cyanea capillata nozakii". This species is found in the pelagic zone off the west coast of Scotland, the North Sea and the Irish Sea, sometimes with the more common Lion's Mane Jellyfish, ("Cyanea capillata"). "C. lamarckii" has a blue or yellow tone and grows to approximately 10 to 20 cm across, but specimens