Synchronised goldfish

One thing that bugs me about the internet (yet it's something I like in equal measure) is that I can spend days researching an article on fish behaviour - the sort of thing I do for a living - and then in a click of a button I can come across something like this film of synchronised fish that says more than I can write in 2,000 words, or does it? If it's some kind of Photoshop stunt then it's very good. If it's the genuine article it confirms what I've always suspected: there is a direct link between fish behaviour and Strictly Come Dancing. Then again, fish do this in their natural environment all the time.