PlanetCatfish.com

Hi everyone,

I'm hoping someone can help. I have a cory catfish who I've had for well over 2 years now. He lives in a 30 gallon tank with 6 black skirt tetras. Saturday night we discovered a blister like bubble on his back. Doing some emergency research online at 2 am led to us removing a large assortment of plants from the tank, as we believed he might have gas bubble disease caused by too much oxygen generated from the plants. I should say that some of these plants are newer thus our worry that we might have too many, etc. We also switched off the tank light and have left it off, along with closing the shades in the tank room to ensure reasonable darkness as recommended online. Melafix was also added to protect in case a bubble popped. Yesterday and today or maybe just on closer examination, it seems like he has more bubbles. (see picture attached from today.) In addition to these odd bubble growths, he has also been breathing rapidly and making little indentations in the sand. He's obviously not happy. He doesn't really seem to be eating. After more research today, I've begun to suspect maybe the filter (a HOT Magnum) is intermixing air or something (I noticed one gasket had been deteriorating last time I cleaned it) and I have switched it off, leaving the air stone working.

Can anyone advise what else if anything can be done for gas bubble disease? Is there any hope of a recovery? I should add that the tetras seem fine.

I do not think that this is gas bubble disease. I may be wrong but I thought that that referred to a condition similar to the bends in divers. It means that gas bubbles form in the blood due to supersaturation with gasses. With divers this happens because nitrogen dissolved in the blood at depth 'gasses out' when the pressure reduces as the diver returns to the surface. With fish it is sudden changes in temperature that are the most likely cause. Cold water (and blood) can contain higher concentrations of dissolved gases than warm water which means that when a fish is suddenly moved from well aerated cold water into warmer water its blood will contain higher concentration of gases than can remain dissolved (it is supersaturated). The result is that gas bubbles form. Unless your tank experiences large and rapid swings in temperature this seems very unlikely to me. The swellings look horrible and I have to admit I have never seen anything like it but to me it looks much more likely to be due to an infection, either bacterial or viral. The fins also look in poor condition. Switching off the filter is a very bad idea. Your fish needs clean well oxygenated water to have any chance of recovery.

I've only seen gas bubble disease once, but it was literally air bubbles under the skin and I don't think that's what your fish has.
I've seen cases like yours reported several times, and AFAI remember it's always been Corydoras.
In short, I have no idea what that is, but it is something which seems to afflict Corydoras. My recollection is that the previous reports said the fish recovered on its own. However, your fish is in extremely poor condition (pop-eye, fins are rotted away, and possibly ich). You could try treating it for external parasites and bacteria, but frankly I suspect euthanizing it might be the best option.

The problem in my opinion has nothing to do with oxygen. Looking at the general shape of the fish I would say that your fish is suffering from to much high protein food. These jelly looking growth often appear when Corys have been fed high protein for prolonged periods. My suggestion would be to change the diet and feed natural foods either live or frozen.

Because the fish is covered in bony scutes when the gel is secreted through the skin, it is channeled to the areas where there is the least resistance and gathers as blobs. Basically your fish is obese.

It may be possible to pull the fish round, but it does look pretty bad.

Ian

I have a Cory with similar looking bubbles on her skin as well... Did you had any luck with treating yours? If so, what did you do?