Japanese Sea Nettle Chrysaora pacifica

The Japanese Sea Nettle is a jellyfish native to waters of the western Pacific coast off Japan and the Koreas.

Despite its Latin name pacifica, the Pacific Sea Nettle is a different, related species of the eastern Pacific. (The Northern Sea Nettle, C. melanaster, of the northwestern Pacific and Arctic is/was also sometimes referred to as the Japanese and the Pacific.)

The bell of the jelly looks like that of its northern counterpart but is much smaller at only some 20-30cm across rather than 60cm of the Northern. The shorter, frilly feeding tentacles and longer, stringy stinging tentacles can extend for around 1 metre (rather than 3m) and cause a very painful sting to humans. Diet is zooplankton and other jellyfish.

Like other jellyfish, they have a multiform life cycle of egg, planktonic larva, polyp, ephyra and medusa. Its polyps were discovered in the wild only in 2009 on some shells while searching for those of another jellyfish.