Thanks, all...
...for your support. The fish was aquired at a SWIMMING POOL in a small town about three or four years ago. The last day of summer, a pool in Washington, MO puts goldfish in the pool and the children catch them, take them home, the parents put them in small bowls and accidentally kill them. That's the way I see it. Our fish had anchor worm, so probably a lot of those fish were sick. In other words, I had no plans to keep fish in the first place; I just wanted to do a good job once I was stuck with the task. Turns out that I really like having a couple of planted tanks and a goldfish, but you get the idea.
AquaticAustin,
I am flattered at your offer, but I am exhausted from my efforts; one fish is enough for now. We may eventually get a tankmate if the fish fully recovers (it still has some fungus on its gill cover and head). I know that you will find a good home for those fish.
Platytudes,
Yes, I am in the medical field; I am an MD. Just hope that my descriptions will help people avoid my mistakes.
Yes, the fish is alone.
I'm going to keep a sort of fish pharmacy from now on. Angel flakes will be part of it. Thanks for the suggestion.
To answer your question about the parasites: I don't know where they came from. The signs were, however, consistent with Spironucleus (I called it Hexamita, but this link suggests that Hex has never been identified in fish:
http://www.cichlid-forum.com/articles/spironucleus.php
So, maybe it was Spironucleus.
Two possible sources of the parasites:
1) I decided not to treat (with alum or permanganate) the last batch of plants I bought. They introduced snails and damselfly eggs/larvae to my small planted tank. These have been delightful to watch, and the snails have been really good cleaners. But the snails may have brought an unwanted organism with them. I think of snails as worm vectors, so maybe the organism was a worm and my diagnosis was wrong. Or maybe there were Spironucleus cysts in the water and they were transferred from the small tank to the main tank with plants. I have been shuttling plants back and forth so the snails can clean them. No problems since the plants arrived in May.
2) The second explanation is more chicken-and-egg. We bought and quarantined a prospective goldfish tankmate about a year ago. That goldfish went into the original tank that our pet had previously lived in. While in quarantine, that fish developed stringy feces and black fins and died! At the time I was clueless and just did frequent water changes. Wish I had known about Spironucleus and treating with Flagyl then. We were grateful that we didn't introduce that fish to the main tank. But, did we buy a sick fish with Spironucleus? Or was our original fish a Spironucleus carrier, and left Spironucleus cysts in the quarantine tank? Did those cysts infect the new quarantined fish?
Our fish may have been a carrier, had Spironucleus from day one, and got sick because the stress of the injury. Now I'm leaving all my tubing and tank paraphernalia in the sun, hoping that it will kill the cysts, but I doubt it. As I type this, I think that it may be time to get out the potassium permanganate...
