to be totaly honest i think he fed them small bit of metal or somethin and has a magnet moving around under the table, that is why the fish are barely moving there fins and moving that fast and it also explains why they stay in that perfect diamond shape the whole time...
One frame at a time, 30 FPS. That's exactly why the ONE goldfish starring in that video was filmed on a plain white background...much easier to isolate him in photoshop when combining multiple takes into one finished video.