One Out Of 43 Fish Gasping At Surface, Intermittently

[eduller]

Hello,
 
One of my gouramis keeps going up to the surface and doing what looks like gasping over and over for air. I have never seen him do this before. I just did my usual weekly water change a couple of hours ago. None of the other fish appear to be having any problems. The tank is long established, I test once a week, and I have never had any ammonia or nitrite readings. Nitrate reads about 5-10 when I test on Wednesdays, and I always do water change on Saturday.
 
I did have a problem with lack of surface agitation leading to low oxygen in the tank several weeks ago, but I fixed the problem and haven't had any issues in weeks. And when that was happening, the neon tetras were the first to show signs. I wouldn't expect a gourami to be the first to react to low oxygen. Plus I just did the water change. 
 
54 gallon tank
77 degrees
11 neon tetras, 10 rummynose tetras, 10 harlequin rasboras, 3 honey gourami, 3 peacock gudgeon, 6 peppered cories, some shrimp and snails
50-70% weekly water change
I use aquavitro premier water conditioner
Just did a water test just in case - 0 ammonia, 0 nitrite, <5 nitrate
 
Any ideas? He will do this for maybe 30 seconds to a minute, then go swim around for several minutes, then return to the surface and do it again. I watched closely, and it's definitely the same one each time doing this. When he's swimming around and not at the surface, he's behaving normally, no rapid gill movement or anything.
 
http/s977.photobucket.com/user/eduller/media/20140531_203604_zps8ce8c304.mp4.html
 
 

 

[Ninjouzata]

Could he be attempting to build a bubblenest? I could be very wrong..have never watched one build one. That's the only thing I can think of. Hopefully someone more experienced comes along soon.

 

[betta fish]

My honey gouramis do this too I think it is normal the behaviour fits yours exactly and I do believe it is because they are trying to build a bubble nest, the surface agitation doesn't seem to let them though but they still try!

 

[eduller]

Oooh I never thought of that! I am a total alarmist, so I always assume the fish are dying whenever they even look at me funny. That makes total sense though - thank you. My little guy is growing up lol!

 

[TwoTankAmin]

Also, do not forget these are Anabantoids which means they have a lung-like labyrinth organ which enables them to breathe air.

 

[eduller]

Yeah I know. I have bettas too. I had just never seen any of them do that before. I guess because there isn't much surface disturbance in any of my betta tanks, it's obvious when they're making a bubble nest because, you know, they actually make bubbles. I guess the one male gourami wasnt old enough to try to make one until now!