Thanks for the help, everyone. Yesterday's weather was much better, and the Tiger Barbs were much calmer. They were a bit off-colour again this morning, but the rain is bucketing it down outside once more.
The only one that showed no signs of improvement was one of my Panda Garras, who was still pale and completely off his food. This morning, I found him dead in the tank, so removed him to have a better look. he had a chunk or two missing from his dorsal fin, and also from one of his pectorals; and down one side, there was blood at the root of his pectoral and pelvic fins. His eye that side was also sunken in.
From that, it looked like the poor thing was bullied to death; from what little I've been able to find out about Pandas, it seems that they can be quite territorial at times, and I must admit that I've seen them both squabbling over algae flakes at feeding time, but I put that down to healthy competition. I guess was wrong as far as Pandas go. The tank volume is plenty enough for them, but size-wise, I guess there wasn't enough room for them both to feel comfortable with their own territory. On other fish forums I had a look at, some keepers bought as many as 10 Pandas for a tank, which all fought with each other until a handful were left, so territoriality is an issue with these animals.
Another thing I've found is that they both looked different. The surviving one has the pronounced slope from the head to the dorsal as described for that species, but the other one was a little longer just aft of the head, with less of a slope. I put that down to being possible sex differences, but again, as far as I know, that might have been a birth defect, and also a factor in his demise. I'm still at loss to explain what happened, but if I find out more about Pandas, or if anyone here has any advice, I'll gladly pass it on.
It's a terrible shame, Pandas are beautiful animals.
