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.

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

Besides causing fiscal and environmental disasters there are other reasons you should keep that goldfish in its tank. More from Science Goldfish may look small and cute in your home, but in the ...

Having active goldfish and poor swimmers in the same tank can be problematic. Park officials said they made it possible by adjusting water currents and providing hiding spots for the fish.