How do they breathe when asleep?

[MissFutureVet]

Well I know that bettas have the ability to breathe surface air. But when they sleep(in a tank with poor air quality,) how do they breathe. do they continually surface to get air, does it disturb their sleeping if they do continually go up for air during the night
.....just curious.

[1fish2fish]

They'll periodically wake up and go to the surface for air. Most of my fish sleep near the surface so all they have to do is raise their head above the water.

[thekoimaiden]

Fish don't sleep like mammals do. In fact, scientists really don't know much about "fish sleep" in general. The theories I've read say it's a resting state where they aren't actively looking for food and therefore don't burn calories. Apply this to aquarium life, and you can surmise that your fish is sleeping whenever he isn't moving much. I've seen my goldfish sleep, but rarely ever see my bettas sleep. I try to provide my bettas resting spots near the surface, so they don't have to move too much to get air.

[MissFutureVet]

Interesting! thanks for the info =)