Aurelia is a genus of jellyfish that are commonly called moon jellies, which are in the class Scyphozoa.

[1][2][3] The genus was first described in 1816 by Jean-Baptiste Lamarck in his book Histoire Naturelle des Animaux sans Vertèbres (Natural History of Invertebrates).

More recently, studies have highlighted the morphological variability[2] (including the potential for phenotypic plasticity[8][9]) in this genus, emphasizing the difficulty of identifying cryptic species.

[10] Species of Aurelia can be found in the Atlantic, Arctic, Pacific and Indian Oceans, and seem to be more common in temperate regions, such as in the waters off northern China, Japan, Korea, New Zealand, the northeastern and northwestern coasts of the United States, and those of northern Europe.

[12] After many tests on frogs, it was determined that A. aurita has a proteinaceous venom that causes muscle twitching by inducing the irreversible depolarization of the muscle membrane that is believed to be caused by an increase in the membrane's permeability to sodium ions.