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Moon jellyfish

Aurelia aurita

Britain's most common jellyfish: a see-through saucer with four pale purple rings in the middle.

Size
Up to 40cm across
Look for it
April to September
Where
Calm bays and harbours, and washed up on beaches

My spotter's list

Drifts after you, squeezing itself along one pulse at a time. Move your pointer and see.

When to look

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Moon jellyfish

Good to know

Six things about the moon jellyfish

Rings

Four rings

The four rings you can see through the top are where it makes its eggs. They make a moon jellyfish easy to recognise.

Water

Mostly water

A jellyfish is about 95 per cent water. It has no brain, no heart and no bones.

Sting

A very mild sting

Its sting is too weak for most people to feel, but it's still best not to touch any jellyfish, even one on the beach.

Moving

Pulsing along

It swims by squeezing its bell, but it mostly goes wherever the tides and currents take it.

Food

A sticky net

Tiny animals stick to the slime on its bell and are passed along to its mouth underneath.

Eaten

Turtle food

Leatherback turtles visit British seas in summer to eat jellyfish.

The real thing

Photos of the moon jellyfish

Moon jellyfish, photo 1
Photo: Luc Viatour, CC BY-SA 3.0, Wikimedia Commons
Moon jellyfish, photo 2
Photo: Hans Hillewaert, CC BY-SA 4.0, Wikimedia Commons
Moon jellyfish, photo 3
Photo: A.Savin, CC BY-SA 3.0, Wikimedia Commons
Out and about

How to spot one

Look down from a harbour wall or pier on a calm summer day, or along the tideline after an onshore wind. Look for the four purple rings.

Lend a hand

How to help

Never drop balloons or plastic bags: turtles and seabirds mistake them for jellyfish. Look, but do not touch.

Keep going

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