Corydoras catfish

[Sicj]

i just bought 6 corydoras catfish and some of them seem to be swimming to to the top of the tank like they are trying to get air then darting bak down to the bottom. They were doing this as soon as i bought them.There is plenty of air in the tank so i dont really know why they are doing this any answers.

[Cichlids_Rule]

Corys do this, I am not compleately sure why, but it is noting to be worried about.

[Sicj]

oh thank god i thought there was something wrong thankyou very much

[flukes]

This is a most common thing with corry's mine even give the discus a bit of a bump on the dart back down, the discus dont seem to mind though

[Jeff]

That is normal behavior.

[luvfishies]

Cories "eat" air, and then the bubble is "digested" in the digestive tract. Totally normal, and nothing to worry about.

[DiscusMad]

mine just plow straight past them when going left to right in the tank if the discus are in the way lol

[lighter]

I notice that if your water is not so good they tend to do this more.

[clothahump]

I notice that if your water is not so good they tend to do this more.

Good point Lighter, poor water conditions will tend to make the Cory's "Gut Breath" more often than normal.
They are capable of this due to the natural environment they come from, some of the ditches and ponds they are found in are very nearly devoid of oxygen at the height of the dry season.