Jellyfish
Jellyfish live in oceans all over the world. Some live near the surface where there is a lot of light. Others live deep under the surface where there is no light at all.
Jellyfish don't have a skeleton. Their bodies are just like jelly. This is because their bodies are made up mostly of water.
There are about 200 species of jellyfish. Most look like floating umbrellas. Their body is shaped like a bell. Their tentacles hang beneath.
One of the biggest jellyfish is the lion's mane. It lives in the Arctic, northern Pacific and northern Atlantic. Its body is 2.3 metres across and its tentacles are 36.5 metres long. If it stood up on its tentacles, it could look into the window of a 12th-storey apartment!
One of the smallest jellyfish is the Irukandji (eer-uh-CON-jee), from Australia. It is just 1cm long.
Jellyfish can be dangerous because their tentacles are covered in stinging cells. These can stun and kill shrimps, fish and other ocean animals.