Science Main Index
There are about 1,500 species of jellyfish and they are found in all oceans of the world. They can also be found at every depth, from floating near the surface to the deepest depths of the ocean. Despite their name, jellyfish are not fish. They are actually a cnidarian. They are called jellyfish because they feel like jelly when touched. Jellyfish look at lot like an umbrella floating under the surface of the water. Jellyfish do not have a brain, heart or blood, but they still manage to live, eat and swim like other marine animals. They move forward by expanding and contracting their bell-shaped body. Jellyfish tend to travel in large groups or swarms carried by the ocean currents. Some jellyfish have a green fluorescent protein that causes them to glow in the water. Some jellyfish tentacles have a toxin capable of stinging and even killing its prey. Play the following videos to learn more about the jellyfish.