Jellyfish have tiny stinging cells in their tentacles to stun or paralyze their prey before they eat them. Inside their bell-shaped body is an opening that is its mouth. They eat and discard waste from this opening.
As jellyfish squirt water from their mouths they are propelled forward. Tentacles hang down from the smooth baglike body and sting their prey.
Jellyfish stings can be painful to humans and sometimes very dangerous. But jellyfish don't purposely attack humans. Most stings occur when people accidentally touch a jellyfish, but if the sting is from a dangerous species, it can be deadly. Jellyfish digest their food very quickly. They wouldn't be able to float if they had to carry a large, undigested meal around.
They dine on fish, shrimp, crabs and tiny plants. Sea turtles relish the taste of jellyfish. Some jellyfish are clear, but others are in vibrant colors such as pink, yellow, blue, and purple, and often are luminescent. The Chinese have fished jellyfish for 1,700 years. They are considered a delicacy and are used in Chinese medicine.