Putting them in bowls is like keeping a large plant in an itty bitty pot. Their growth gets stunted and it's cruel like Pikey said, and they become unhappy so they get more and more stressed and pollute the water more and more and it's just a vicious cycle.

As for air, yeah, they need a filter for circulation.

pikey how do you feel about the fact that we have extensive knowledge about goldfish handling and care