Did you know?
No bones, no brains, no teeth, fins or even blood – in fact, jellies are mostly water. But they survive in oceans all over the world, and are mesmerizingly beautiful as well.
Drift with Jellies
Meet our jellies
Jellies use stinging cells to sting and immobilize prey. The long oral arms begin to digest the prey and bring it to the jelly’s mouth, found under the bell.
Most jellies eat plankton, plus young shrimps, crabs, fish and other jellies. They’re eaten by other fish, and leatherback turtles travel for miles to eat Pacific sea nettles.
Adult jellies (‘medusa’ form) release sperm and eggs, which combine into free-swimming larvae. These settle onto rocks and grow into a polyp.
Polyps catch zooplankton with their tentacles, developing stacks of frilled discs that break off, drift and grow into adult medusae.
Watch that sting
and give a squeeze
Most jellies have mild toxins that don't bother humans. But some can be as painful as bee stings, and a few, like the sea wasp, can be extremely dangerous.
Giving their transparent muscles a synchronized squeeze, a jelly throws its body into a wave to move outward from the bell and push it through the water.
THE THREAT: Jellyfish play a vital role in the ocean food chain, eating plankton and giving food to turtles and fish. Their populations are stable – but recently they’ve been “blooming” in unusual places.
TAKE ACTION: Scientists are still studying how human activity and climate change affects jellies. Meanwhile, it is threatening many other ocean animals. Find out how you can help.