Barrel jellyfish

Barrel jellyfish ©

Barrel Jellyfish

Scientific name: Rhizostoma pulmo
The largest jellyfish found in UK seas, most people's first encounter with them is when they wash ashore in early summer. No need to be afraid though, their sting is harmless to humans.

Species information


Bell: Up to 90cm across Weight: Up to 35kg

Conservation status


When to see

May to October


This large jellyfish swarm in warmer coastal waters in late Spring and often wash up on our beaches in May or June, sometimes in their hundreds. They are the size of dustbin lids - giving them their other common name: Dustbin-lid Jellyfish! They are attracted inshore by plankton blooms which provide a plentiful supply of food. They have 8 arms, each frilly in appearance. These frills actually contain their small stinging tentacles which surround hundreds of little mouths!

How to identify

A large translucent jellyfish with a huge mushroom shaped bell and a bunch of 8 frilly tentacles below. They don't have marginal tentacles, but do have a violet fringe around the bell which contains sense organs. They are often found washed up on beaches in May and June.


Common off Southern and Western coasts of Britain in summer months.

Did you know?

Barrel Jellyfish are the favourite food of Leatherback Turtles, the world's largest sea turtle.

How people can help

Report your Barrel Jellyfish sightings to your local Wildlife Trust. The Wildlife Trusts are working with sea users, scientists, politicians and local people towards a vision of 'Living Seas', where marine wildlife thrives. Do your bit for our Living Seas by supporting your local Wildlife Trust or checking out our Action Pages.