Koi behaviour

[agardner09]

This is a question for any koi experts out there. This morning for many days was the first time I could see through the melting ice on my deep pond. I noticed one of my larger koi (about a foot long) lying belly up on the bottom of the pond, apparently a goner. It was still there about half an hour later when I was going to chip a hole in the ice to recover the corpse. However I then noticed slight movement of the fins and within a few seconds it had righted itself and was swimming normally. A while later I again noticed it belly up and again after some time it righted itself and swam normally.This is the only fish to be affected. Is it usual or should I start worrying?

[wildwood]

I am no expert but even I know that a fish belly-up is not usual. There is obviously something wrong, maybe an infection that prevents the swim bladder from holding the fish's equilibrium. There are heaps of specialist fish club sites on the net and, unless you get a quick answer, it may be advisable to visit them and ask your question on several sites. Good luck.