Rapidly breathing Cories

[davemill]

Hi, all,

I have a mature (10 years since setup) 72 gallon, heavily-planted community tank. Occupants include angels, apistos, rummynose tetras, ancistrus, plus three corydoras species (Corydoras trilineatus and two species resembling Corydoras paleatus). Three of the cories were purchased at adult size nine years ago, and the rest of the cories were obtained as adults 3+ years ago. The ancistrus frequently breed in the tank. Soft water, pH 6.3, CO2 injection, and 50% water changes 1-2 times per month.

Here's the question: When I observe the C. paleatus-type cories, about half seem to breathe very quickly, four or more times per second. The others breathe more slowly, approximately 2 times per second. I can't be certain, but it also seems that these faster-breathing cories spend less time hunting and more time resting than the others. These fish are otherwise healthy, showing up with the others during feeding time.

The situation has been stable for a long time. I first noticed this a year or more ago, but my daughter noticed it and pointed it out to me again this weekend. I am wondering whether this could be caused by something like gill flukes? Should I leave well enough alone, or attempt treatment?

Please note that any treatment must treat the entire tank plus occupants, as it is essentially impossible to catch any gravel dwellers among the plants and driftwood.

[crkinney]

Do they smoke?

[Bwhiskered]

Gill flukes are a good possibility. The whole tank could be treated with Life Bearer. It won't harm anything and may help the problem.

[Coryman]

If it was gill flukes then it is a safe bet that the whole tank would be infected and if this problem was noted a year ago then it would have been a major problem long before this.

The problem could be a combination of temperature and or CO2 (you don't say what it is). C. paleatus prefer a cooler range than the so called tropical 24ºC - 26ºC,the would be happier at 21ºC - 22ºC. is the CO2 on 24/7 or is it turned off at night?

There could be a number of other contributory factors, such as nitrite. Have the fish been subjected to high nitrites at any time, this can certainly have an effect on breathing.

Ian