Did you know?
Jellyfish have fish in their name, but they are not fish. They live in every ocean in the world, even in freshwater lakes too.
Jellyfish are made up mostly of water. They have no heart, no blood, no eyes, no bones, and even no brain.
Jellyfish are shaped like a bell or like an umbrella. Some of them can glow in the dark.
Jellyfish may be tiny or quite large. The smallest are the size of peas. The largest are 20 m in a diameter.
Jellyfish feed on small plankton animals. If there is not a lot of food around, they can shrink in size, so they need less food.
Jellyfish are extremely harmful creatures of the deep. They can sting and cause pain, and some of them can kill people.
Jellyfish are ancient creatures. They first appeared about 650 million years ago.