Also from the Hoax Forum (January 25, 2006): http://www.post-gazette.com/pg/06024/643104.stm

I don't think I'd have the patience...

CUUUUUTE!! Even if it's not real, I think the clip is fun.

And it's a Chinese variety show.

It's probably real, though it may not be the hand motions that are really signalling the fish to turn. Training fish is nothing new (to the chagrin of people who'd rather believe fish have no memory!). I've seen goldfish trained to ring bells and jump through hoops. And I personally once trained my Oscar to jump in the air and take food from my fingers, swim to either end of the tank on command, or swim in circles.

It's a Japanese TV show, but apparently it has been edited by a Chinese TV channel -- there's a different voice-over at the end, that's Chinese, not Japanese.
I also didn't know fish could be trained. Adorable.

I think it's done with magnets under the table.

^^ You think magnets? Like they poured buckshot or something similar into the poor little things and have a magnet dragging them around in formation? Would make sense but could you put enough metallic substance in a goldfish for a magnet to affect enough to move them around... and not kill them? Maybe they're using those "Super Magnets" the neodymium AKA rare earth magnets.... hmmm

Possibly ingested or the magnet could be attached to their bellies. You don't really see beneath them and there isn't an obviouse shadow underneath. Looks like they're stuck to the bottom. The propulsion from their fins doesn't look like it would be able to move them like that. I'd expect more wiggle of the tail fin. Around second 43 they back up the two fish on the left and, to me, it looks like their movement indicates a stressful reaction rather than a fish reversing itself. If this was originally presented as a magic effect I'm sorry for exposing it.

Magnets?
You've been smoking too much of that Arkansas Polio Weed.
As I said, it's really not all that hard to train fish to do simple things. Mostly, it requires a lot of patience.

I've trained my betta to come to one corner of the tank when I tap on it.

I don't doubt someone could train four fish to swim in formation. Odd hobbies are legion.

But what's with that peculiar white hat?

"It's a Japanese TV show, but apparently it has been edited by a Chinese TV channel"
You're on the money. JET is a Taiwanese channel that regularly carry voiced over Japanese programming. I believe their redubs are also regularly sold to other TV networks. The channel is available over cable in Singapore, and some of their programming is available over another channel over here in Malaysia.

I'm going to agree with the magnet crowd here, or something along those lines. I have a goldfish almost identical to these, except it has the pop eyes, and if it was swimming at those speeds there'd need to be a lot more tail action going on.

I think there's not even sufficient water in the tank for them to swim in! Near the end a goldfish looks like it's beeing dragged and touching on the bottom of the tank. Magnets here too

God, I hate to say it, but is it possible that the little critters are hungry?
Perhaps they've been fed by hand & its natural to follow that hand looking for food...

This is anything but real, take it from someone who breeds fish and has 8 tanks between 5 and 80 gallons (plus countless smaller betta tanks). Their movement is very unnatural, you'd expect fancy goldfish like these to be putting forth more effort to be moving at those speeds. Just watch in the last 3 seconds or so and you'll see the fish on the far right struggling unsuccessfully to swim out of formation. No animal, no matter how clever and well trained, is going to be capable of performing as perfectly as those goldfish did in the video. I don't know exactly how they did it, but like others mentioned, my bet is magnets.

Now if you want videos of REAL trained fish doing their thing, go here:
http://www.fish-school.com/gallery.htm

Although magicians aren't supposed to reveal secrets, I've spent a number of years making a living through the art of illusion and I can say, that although I can't be sure of the vid clip version, I can be sure that it can be duplicated using strong pinhead sized neo magnets. A single magnet is glued (using one of the ever popular super glues) on one side of each fish just below the mouth and gill. The trick "operator" is under the table dragging two sticks embedded with magnets on each end (covered with padding to prevent noise and water ripples) in a pattern know to the "trainer".

I would bet that the vid clip being discussed is performed in exactly the same manor because:
1) Goldfish normally swim perpendicular to the ground, and not flat like flounder or stingray.
2) The amount of water used will not allow the fish to swim perpendicular to the ground, or flip over, therefore only allowing the magnetic side to always remain close to the bottom of the shallow tank. This position and the amount of water also assures that the fish can't get a full "tail-swing" to enable enough force to break free from the magnetic pull.

I suspect that the reason we don't see this much outside of Japan or Singapore (or other fish "friendly" countries), is because our animal rights laws (here in the United States) would destroy the act before anyone could turn a profit.

Most likely, animal rights activists would close down any demonstration of animal (fishes included) cruelty, much the way they have done in the past, (I.E.: "The Tap Dancing Chicken")

Hope this helps, and also hope this doesn't become the next craze for kids, like the mentos and soda experiment which has no doubt caused a few extra paint jobs here and there.

PS: Love your site!

Animal rights laws here in the US actually don't protect fish, nor reptiles I don't think... A big fuss would be made about this sort of happening in this country, but legally there's nothing that can be done without putting new laws on the books or changing up the current ones to include fish.

Thanks for the comment on animal rights laws in the US. (Perhaps I should have used the word "activists" instead of "laws".) I did use the words "I suspect that" and "Most likely" so I wasn't sure if it was a law or not.
I do know that the exploitation of any living species seems to always have some sort of group waiting in the wings, ready to slam down some sort of "morality" issue. I could easily see how "modifying a goldfish with glue and magnets for personal gain" could end up on the evening news here in New York.

Oh absolutely, no argument there -- the ASPCA will sometimes step in in such situations, but legally speaking there's nothing they can do. In pet shop situations, usually the threat of their presence is enough to make a shop clean up its act... most places aren't too happy about having an animal welfare group show up in front of customers ya know

Oh you dis-believers you! I had a Sturgeon (normally a bottom only feeder) that I had trained to come to the surface and take food from my hand (his nose would stick out from the water). He would also swim across the top of the water either upright or on his back (a bit like a trained dolphin). It would take the sound of food for him to come to the surface but once he was there he would do his tricks. Chances are these goldfish have been trained the same way. They are following the trainers hands waiting/expecting to find food.