I don't quite know about exploding as in KABOOM and then little fishy pieces all over your tank but if you feed them too much they are dumb enough to try and eat it all and die.
That is what Ryunkin Goldfish look like. If however, the fishes scales are sticking out like a file or rasp, the fish is suffering from a fatal disease called Dropsy. There is no known reliable cure...
There ancestors are gold... different colored traits over time dominated the classic gold color, while in some breeds, the gold color will dominate during the trait selecting process
Because it will be matingg season for your goldfish'swich means one of them is a boy and the other a girl.the girl will be the one with the mostly wided V tail, butremember goldfish lay from 15-20...