Fish Bowl???

[ILoveReptiles]

About the only fish that I know of which can live comfortably in a goldfish bowl is a Betta. And that's only because they frequently come to the surface and gulp a breath of air.

In the natural world, they stake out very small territories in flooded rice fields. The water gets pretty stagnant, so they've developed a sort of "book lung" (halfway between gills and lungs).

Goldfish need a filtered tank.

[IRescue452]

http://www.bettadreams.com/ricepaddies.html

This small territory you speak of can be twenty gallons or more. The heavy load of live plants also keeps the water very freshlike and keeps nitrates down.

[Christmas_Hamster]

You were very smart to ask first. Goldfish need lots of room. A good rule is 2.5 gallons per inch of full grown goldfish.

Bettas are okay in goldfish bowls though