Goldfish possess genetic traits that allow them to swell up to four pounds—the size of a Chihuahua. Experts say that's why ...

But in your home tank, there's no bacteria to be found. You have to introduce it, and that's where a lot of goldfish owners slip up because you can't just buy a fish the same day you get your tank.

The USFWS asks goldfish owners who can no longer keep their pets to rehome them or return them to a pet store — or even ...