This is what YouTube persistently advertised to me. Hope you don't get the same "targeted advertisement", but chances are if all of your YouTube subscriptions are about aquariums you will. Because someone paid for that to happen.
A movie about Freshwater fish traders, discus, arowanas, piranhas... and more. Ugliness. The stuff that hardly leaves an impression on anyone but people like me that do not watch TV:
http://www.youtube.com/watch?v=HmQPIBNPFBE
01:51 - "...My idea of it is that it's a chunk of rocks..."
If you find yourself actualy paying to see that movie you have just learned something ugly about yourself.
Cheers! (Except I do not drink either.)