I'm find jellyfish curious creatures and have previously written about giant jellyfish taking over the oceans. Today I learnt on wikipedia the jellyfish's mouth and anus are one and the same.
This is because it has a simple digestive cavity which acts as a gullet, stomach and intestine all in one, with one opening for both the mouth and anus.
Jellyfish are fascinating.
"Their bodies have radial symmetry, which means that the body parts extend from a central point like the spokes on a wheel. If you cut a jellyfish in half at any point, you'll always get equal halves."(From how stuff works).
They are also about 98 percent water which is why when you see a jellyfish washed up on the beach, it will have mostly disappeared, as the water evaporates. Jellyfish do not have a brain, heart or bones.