They're deformed and caused by extensive inbreeding... look around long enough on the net and you'll see the ones that didn't make the cut, they truly are hideous. They also generally don't well at all, the majoity of them die pretty quickly or have SEVERE swimming and swim bladder problems. With things like this, it's only a matter of time until we have double-tailed, bubble-eyed and finless Asian arros selling just like goldfish. It's a shame that such a magnificent fish has been reduced to this. 
