What are my guppies doing?

[Cjbear087]

I did a PWC about an hour ago, and some of my guppies seem to be hovering at the surface, and they look like they are opening and closing their mouths. They have never done this before. Sometimes they come back down for about 5 seconds and then they dart back up again. My gourami is fine, my corydoras and a few of they guppies. Whats wrong? Sorry for the low fps, I can only upload as a gif.

[mynameisnobody]

Did you add water conditioner/dechlor? 

[Cjbear087]

On 4/8/2024 at 9:39 PM, mynameisnobody said:

Did you add water conditioner/dechlor? 

Yep, very strange

[jwcarlson]

Did you stir up something they're trying to eat?

[Cjbear087]

On 4/8/2024 at 9:50 PM, jwcarlson said:

Did you stir up something they're trying to eat?

Nope, normal feeding routine and everything. This started so suddenly and I don’t know whu

[jwcarlson]

It's tough to tell from the gif, but were they acting upset or lethargic or anything?  Seems like they're moving normally to me?  Maybe they were happy?  Some fish really seem to like water changes.

[Cjbear087]

On 4/8/2024 at 10:00 PM, jwcarlson said:

It's tough to tell from the gif, but were they acting upset or lethargic or anything?  Seems like they're moving normally to me?  Maybe they were happy?  Some fish really seem to like water changes.

They werent acting lethargic, but they sometimes moved quite sporadically and were very jumpy. They were basically staying at surface and mouths were opening and closing. Although ive just turned my light off and they seemed to have stopped which is very strange

[AtomicSunfish]

If I had to guess, I'd say they were performing aquatic surface respiration (ASR). This is something that livebearers and cichlids, which do not have an air-breathing organ, will do when oxygen levels get very low. Even if oxygen levels are low below the surface, there is still a thin layer of highly oxygenated water right at the surface that's only about a millimeter thick. These tropical fish know how to breathe in just that thin film of water, so they can get enough oxygen.

It makes sense if the gouramis and cory cats are not in distress, since they can both breathe atmospheric oxygen (gouramis have a labyrinth organ, and cory cats can breathe with their stomach if they need to).

Is there reason to believe your tank is currently suffering from hypoxic water? You say you added water conditioner after your water change. If you accidentally added too much, that could bring the oxygen levels down in the water. Might want to consider doing another water change, this time using less conditioner if you did indeed accidentally overdose.

Edited April 8 by AtomicSunfish

[Cjbear087]

On 4/8/2024 at 10:46 PM, AtomicSunfish said:

If I had to guess, I'd say they were performing aquatic surface respiration (ASR). This is something that livebearers and cichlids, which do not have an air-breathing organ, will do when oxygen levels get very low. Even if oxygen levels are low below the surface, there is still a thin layer of highly oxygenated water right at the surface that's only about a millimeter thick. These tropical fish know how to breathe in just that thin film of water, so they can get enough oxygen.

It makes sense if the gouramis and cory cats are not in distress, since they can both breathe atmospheric oxygen (gouramis have a labyrinth organ, and cory cats can breathe with their stomach if they need to).

Is there reason to believe your tank is currently suffering from hypoxic water?

I am currently dosing my tank with Fritz Expel P (levamisole) for camallanus worms. I treated it yesterday so could be that, although when I dosed last week they weren’t doing this. I also have an air stone in the tank, so really the o2 levels should be low.