There have been 2 or 3 "for tv" movies about snakeheads... frankenfish or something like that was one of 'em. Also, fish played a part in one of the Hannibal Lecter books (3rd one I think), don't know if it made it into the movie or how it was done if it was...
the movie Blood Surf was hilarious!!!!
Zoo Diver I think the idea of creating a shoal of pirahna in an exibit would be awesome. I think you should do red bellies as they have a bad reputation but are actually not as bad as everyone thinks. I also think a snakehead exhibit with bleheri or some other smaller pretty snakeheads would be educational and show that not all snakeheads grow to be 4 ft monsters.