How long do jellyfish live?
Most jellyfish probably live no more than a year, and many may only live a few months. In captivity, jellies like the purple-stripe jelly, moon jelly and sea nettle can live for 2 to 3 years. In their natural habitat it’s generally thought these and other larger types may live about a year, and maybe up to a year and a half. Small jellies, like crystal and umbrella jellies, probably live for 4 to 6 months at most. Generally the smaller jellies are pretty short-lived and may only be around for part of the year. It’s difficult to know for sure how old jellies are since they can’t be tagged and tracked like fish, and they don’t have any kind of growth rings that indicate age. For comb jellies, the sea gooseberry may live 4 to 6 months, and in captivity, lobate comb jellies can live for over a year (probably a lot less than this in natural habitats).
