Can not having an air pump kill your aquarium fish?

if you have 1 or 2, then no. just dont put a tight cover on the cage because the fish use our oxygen from the top of the water to breathe. if you have a bunch of fish,you might need one. :)

It is possible your fish will not survive without the pump. It depends on what you are using to induce air into the water.

There are some varieties of fish that do not need a pump such as gold fish and bettas. Call your local Pet store for more information when in doubt. Most fish tank kits come with a pump included.

Technically, the "air pump" is not necessary at all; oxygen does not get into the water from the bubbles. What the bubbles really do is cause the water to circulate, bringing water up from the bottom of the tank to the top of the tank where it can pick up oxygen from the air. Any other method of circulating the water in the tank would work just as well.