Barrel Jellyfish Rhizostoma pulmo

The Barrel Jellyfish is native to temperate coasts of the eastern Atlantic from the UK to the Mediterranean and Black Seas and off southwestern Africa. It is one of the two largest jellyfish native to UK waters (the other being the Lion's Mane Jellyfish).

It is mushroom-shaped, whitish-coloured with a narrow violet edge to the bell and eight frilly tentacles. Sometimes washed up on beaches, the tentacles have a moderately venomous sting, even when dead.

They can exceed 90cm (3 feet) across and live in large swarms. Diet is zooplankton. Like other jellyfish, they consist of 90% water.