Jellyfish Over 200 different species of jellyfish are found throughout the world's oceans and seas. They come in many shapes and sizes, ranging from the tiny, spherical thimble jellyfish of the Caribbean to the largest jellyfish of them all, the Arctic lion's mane, whose tentacles may stretch over 100 feet in length. The bell, or body of a jelly fish has one or more mouths on its central oral surface.
Some jellyfish have frilly oral arms around the mouth.
Jellyfish feed on small, drifting animals called zooplankton - which includes other jellyfish, juvenile fish and larval crustaceans. Tentacles, long string-like structures that surround the bell rim, trap food. These tentacles can be longer or shorter than the diameter of the jellyfish's bell. Despite limited sense organs, jellyfish can smell, taste and remain balanced in the water. Special sacs, located on the bell rim, help jellyfish maintain balance.