My old Cory stopped eating a long time ago, Help

[EllenAliciaJordanScusa]

Hello everyone,
I wasn't actually going to come here but instead immediately put some of the medication I have left in the tank but stopped. So, I have a corydora that is about 7 years old or so. Very healthy all her life. I have two other corydoras with her that remain healthy and are fine. O.K. so my cory stopped eating over 10 days ago! She is normally very active and a pig. I watched her this whole time after feeding not move around and consume no food. I don't know how she is still alive. So, of course I figure she is sick. However, she absolutely no disease symptoms on her body. The only thing different is she is not eating or moving around. When I put her in the hospital tank yesterday she fought me but pretty weakened. I know her usual fight. I was so worried the stress alone would finish her off but she is still alive. Since there are no symptoms I have no idea what medication to give her. Does anyone here have any ideas?
I did have an angel fish die about one week before she stopped eating. The thing is, I don't know what my angel fish had either. But there was one symptom. One of his eyes was bulging out. Only one though. He stopped eating and died only a few days later with no other symptoms.
I have API Fin and Body Cure and also Maracyn two. Oh, something else that might be important. I began treatment of aquarium salt when my angel fish when he got the eye problem. A very little starting dosage. He died before I could raise it. Maybe that is the problem since I have read corydoras don't like salt. But my other two corydoras are perfectly fine and active. Totally unaffected by it. I began taking the salt out a while ago and had most out when I swapped tanks yesterday. She wasn't getting any better with less salt. And I never had a problem before with my cory's and salt. I don't know. Anyway, I was thinking of starting with one of those bacteria medications. I don't want to lose her although I know I probably will. What else can I do? Suggestions? She is living in the same tank with water quality and all that the exact way for years and years. So, its not that. I am running out of time. thx
p.s. I put this in a different forum 2 days ago but didn't get any responses and I am worried. so, I put it here where I have been a member also.

 

[Byron]

First comment, never, never add some medication/treatment/salt unless you have a very good idea of the issue, and if that product is safe and effective for that problem. I have no idea what the issue/issues are here, and won't guess. But do water changes, more of them cannot hurt if parameters (these are GH, pH and temperature) arethe same basically. How often and what volume are normal water changes?

What are you feeding the fish? How do you know the cory stopped eating? I have never been able to observe this myself, other than by seeing bug bites or shrimp being taken up and not come flying out the gills.

I will say that one, two, three cory are going to be stressed. This is a shoaling fish, it must have 10 or preferably more. And over time, fewer will increase stress and this weakens the fish including the immune system making other problems easier. Don/tbuy more fish of any kind until this is sorted out, but keep this in mind. What is the tank size (volume and dimensions)?

 

[seangee]

What @Byron says is correct, but at 7 years it could just be old age and maybe not something that you can do anything about.

 

[GaryE]

A Corydoras can live 10 to 12 years. Not all do, and it could be age related. But 7 isn't an old Cory.

You've left out what to me is the biggest clue. How often have you been doing water changes, and how much do you change each time? An angel with a bulging eye says bacterial infection, and unless you had just gotten the fish, that suggests a water quality issue. Your test kits can read within the range you want, but with no regular week to 10 days water changes, that's the kind of thing that happens. Test kits are just indicators to be used along with regular water maintenance.

Corys and other armoured cats can be hard to diagnose, because they have that hard body armour that hides an awful lot. But if you think you had a rise in ammonia from the dead fish, that means you didn't do a water change after you found it. In a situation like yours, experience tells me I should start changing water more regularly this week, and at least 25-30% weekly after..

 

[Byron]

Ian Fuller on lifespan from his FB page Corydoras World when asked this question:

20 years plus. 20 to 25 years in not unusual. I have has several long lived groups the first C. pygmaeus 14 years, C. sterbai 20+ these were adults when I first bought them. CW009 I had a group fo 14 years before passing them on an d they are still going. Given god conditions and care these guys will live a very long time. I knew of a female C. aeneus that was over 40 when she died.