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Barrel Jellyfish

Rhizostoma pulmo

Barrel Jellyfish
Photo by Juraj Ahel · CC BY

About

The barrel jellyfish is one of the biggest jellyfish divers meet in the northeast Atlantic and the Mediterranean. It grows up to 90 cm long, though most reach around 60 cm. Its big, round bell has earned it the nickname "dustbin-lid jellyfish."

Also known as: barrel jelly, mediterranean barrel jelly

Length
60 cm · max 90 cm
Depth
up to 40 m

How to tell it apart

Unlike stinging jellyfish with long, trailing tentacles, this species has no tentacles hanging from its bell. Instead, look for the big, dome-shaped bell with thick, ruffled mouth-arms hanging beneath it.

Appearance

Its other common name, the frilly-mouthed jellyfish, tells you what to look for. Thick, ruffled mouth-arms hang below a large, solid, dome-shaped bell, instead of long trailing tentacles.

Behaviour

Barrel jellyfish gather in large groups, called blooms, in late summer and early autumn, when warm water and wind suit them. Their sting is only mild. It can cause a slight burning feeling or skin irritation, but it is not dangerous to people. Leatherback turtles love to eat them.

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