This site uses cookies. View our Cookie Policy to learn more about how and why.

Regular hours: 9:30 am – 6 pm
Last entry at 5 pm

A white wave shape.

Moon jelly

Learn more about these ancient drifters of the sea!

Jellies have been around for hundreds of millions of years—since before dinosaurs roamed the earth. They’re members of the phylum cnidaria, pronounced NYE-daria, from the Greek word for “stinging nettle.” This group of invertebrates is made up of animals that have stinging capsules in the tentacles surrounding their mouths. Puget Sound is home to well over 340 species of cnidarians, including the moon jellies at the Seattle Aquarium.

At the Aquarium

About those stings

All jellies carry a sting—it’s what defines them as cnidarians. But the severity of that sting varies greatly from species to species. For instance, the sting of a box jelly, found in the waters around eastern Australia, can kill an adult human in less than three minutes! Lucky for us, the jellies found in Puget Sound aren’t very dangerous—but their stings can still cause plenty of pain and irritation. It’s best to stay on the safe side and not touch them. Be careful: even dead jellies that have washed up on the beach can sting!

Quick facts

Jellies have been around since before dinosaurs roamed the earth!

Jellies are the largest form of plankton.

These invertebrates have stinging capsules in the tentacles surrounding their mouths.

Explore More Invertebrates

Website maintenance

Please note: Our ticketing and membership systems will be offline for approximately two hours starting at 9pm Pacific on Tuesday, February 20. During the maintenance window, online ticketing and membership will not be available.

Thank you for understanding.

Support the Seattle Aquarium

Two sea otters at the Seattle Aquarium floating on the water in their habitat, holding onto each other demonstrating a rafting behavior.

With your help, the Seattle Aquarium builds connections with our community to inspire conservation and curiosity for marine life. When you make an end-of-year gift by December 31, you'll be joining us in protecting our shared marine environment—now and for generations to come. Thank you!

An adult sea otter at the Seattle Aquarium looking upwards with its front paws resting on its front.

Giving Tuesday

Make a tax-deductible donation to the non-profit Seattle Aquarium

Your donation will be matched dollar-for-dollar up to $10,000 thanks to a very generous anonymous donor!

Sea otter at the Seattle Aquarium laying on its back, raising its head and front paws.

Cyber weekend

Get 15% OFF all memberships!