Moon jellyfish Facts for Kids
Aurelia aurita · aw-REE-lee-uh aw-RY-tuh
A jellyfish with no brain, no heart and no bones at all.
- 🏃 speed: not yet checked
- ⚖️ weight: not yet checked
- 📏 12 in30 cm1 long
- 🎂 lifespan: not yet checked
- 🍽️ tiny sea life
- Not on the Red List (Not assessed)
The moon jellyfish is a soft, clear bell that floats in the sea. It pulses to move along. It has four pale rings in the middle, like little moons.
A moon jelly mostly drifts with the currents, pulsing its bell to push itself along. Food sticks to the slime on its bell, and tiny hairs sweep it toward its mouth. Its stinging cells are weak, so a moon jelly's sting is very mild, but it is still best not to touch any jellyfish.
A jellyfish is not a fish. It is related to sea anemones and corals, and it is almost all water. A moon jelly starts life as a tiny polyp stuck to a rock, and the polyp makes little jellies that swim away. Tiny spots around the edge of the bell sense light and tell the jelly which way is up.
How big is a moon jellyfish?
Moon jellyfish in numbers
| Length | 12 in30 cm1bell width |
|---|---|
| Height at the shoulder | no checked number yet |
| Weight | no checked number yet |
| Top speed | no checked number yet |
| How long it lives | no checked number yet |
| What it eats | plankton, tiny animals and fish eggs |
| Where it lives | coastal waters all over the world |
| What kind | Bugs and other animals without backbones |
| Is it in danger? | Not on the Red List (Not assessed) |
A number we couldn’t find on a page we trust says so, instead of guessing.
Wow!
- It is not a fish: its closest relatives are sea anemones and corals.
- It starts life as a tiny polyp stuck on a rock.
- Tiny spots on its bell sense light and tell it which way is up.
Compare the moon jellyfish
Friends and neighbours
Ocean sunfish
Leatherback sea turtle
ClownfishThree questions
Books about the moon jellyfish, free at the library
Ask a grown-up to tap the button: it shows where to borrow a book about the moon jellyfish for free.
Where these numbers come from
- National Park Service, Fort Matanzas National Monument, checked 30 October 2026.
- Wikidata, Moon jellyfish (Q26864), checked 30 October 2026.