First Aquarium to Breed the Largest Jellyfish Found in UK Waters

To mark World Jellyfish Day today, SEA LIFE London is debuting its brand-new species, the Barrel jellyfish, becoming the only aquarium in the UK to have bred the species from polyps in its specialist breeding laboratory. 

Known as the giants of the jellyfish world, these incredible creatures are the UK’s largest jellyfish, can grow up to one metre wide in the wild and have eight thick ‘arms’ on which tiny tentacles are arranged, giving them a bulky, frilly appearance. We only see adults of this harmless jellyfish in UK waters in the spring and summer.

It’s the first time the massive mushroom-shaped species will go on display at SEA LIFE London Aquarium where, in a UK first, the expert team of aquarists have raised these wonderful creatures from juveniles and are excited to see how large they can grow.

Jack Willans, Senior Aquarist and Lead Jellyologist at SEA LIFE London Aquarium, said: “It’s pretty special to be the only aquarium in the UK to have reared Barrel jellyfish and put them on display. It’s the perfect way to celebrate World Jellyfish Day.

 “It’s not been an easy feat to raise the Barrels as we’ve needed to ensure the water and feed remain consistent to allow them to grow, however I’m proud to say here at SEA LIFE London Aquarium we’ve managed to do just that. Barrel jellyfish can grow up to 50cms in diameter, so watch this space to see how big ours get!”

Ocean Invaders is home to approximately 11 jellyfish exhibits, with more being bred behind the scenes. Current species on display alongside the Barrel jellyfish include Moon jellyfish (Aurelia aurita), Rocket jellyfish (Leuckartiara octona), Upside-down jellyfish (Cassiopea sp.), Pacific Sea Nettle (Chrysaora fuscescens) and Marble jellyfish (Lychnorhiza lucerna).