This fishy fact is about Jelly fish. The fish that sounds like you should be able to eat it but in a cruel twist of irony is the only one that you probably shouldn't eat, well not alive anyway, it may sting a bit.
Jelly fish are more or less all water, 96% to be exact. They don't have any skeletal structure to them at all, and they aren't the smartest fish either because they don't even have a brain. You could punch one in the face all day and it wouldn't bruise or even feel the pain as they don't have any blood nor do they have a nervous system.
Jelly fish eat and excrete through the same hole. It doesn't bare thinking about if humans did the same thing. Sounds like something from the human centipede. They do however look really really cool. Have a look at this video:
So thats jelly fish. Strange things.