on the fish that lost equilibrium. I had it isolated in the fry box (you will see that in the corner of the tank in some upcoming pictures) so I could easily catch it for epsom salt baths. It had been ill for a week, and isolated for five days. I don't know what this could have been, other than swim bladder disease- I fasted the whole tank for two days when I first noticed it, then fed them all peas. No change, the affected fish looked a bit worse. It was struggling to swim upright with a kind of rocking motion. Caught the fish and started giving it epsom salt baths twice a day. It did look a bit swollen or bloated at first, and that symptom went away. But the trouble with balance only got worse. For three days it kept batting its nose on the mesh side of the fry box trying to get out into the tank, any pause in paddling its pectoral fins and it would start to sink tail first. Last two days it wasn't even trying to get out of the box, just padding around nose up tail down, gasping occasionally at the surface. I offered pea bites again and it was not interested. I did water tests and partial wc on the tank, nothing seemed amiss, no other fish affected. In all that time it hadn't pooped once, so if there was a blockage it wasn't coming out.
Maybe I didn't do strong enough epsom salt baths? Knowing tetras are sensitive I started out doing them for ten minutes before re-equalizing the water, using 1 tsp per gallon. Then I used a teaspoon and a half, and the final time, 2 tsp, keeping the fish in the bath 15 min. It didn't seem to make a difference. The strangest thing was something I saw of its behavior. During the last bath the fish was aimlessly paddling around the bucket keeping itself upright like usual. Normally it flees in a panic from the net, but this time when I eased the net into the water and slowly moved it towards the fish to corner it, the tetra turned and swam straight into the net, and laid down on its side as I lifted it out. I thought at first it was just exhausted or disorientated, but the instant I dipped the net into the fry box it calmly turned and swam out of the net, and went back to batting its nose against the mesh wall. Its motions in and out of the net could have been coincidence? but I do wonder if it was becoming familiar enough with the bath experience to know the net in the bucket would put it back in the tank? I don't know.
After three days of epsom salt baths I left it alone in the fry box for two days, hoping time and the laxative would work... but no. Finally I started to feel guilty at keeping it alive, its nose was banged up from bumping on the netting all the time, and it looked like it was really struggling. I didn't see any hope of recovery. I folded 'Nito into a damp paper towel, euthanized it quickly with a rock, wrapped in a large leaf and buried it under the hydrangea. Luckily the ground there wasn't quite frozen yet.
QT. This photo of the main tank has corner shielded with a cloth, where the fry box hung. I was trying to reduce stress by keeping it shaded.
My other ill serpae, Punk, just moved out of the ten-gallon hospital tank back into the thirty-eight home tank. It went through a full treatment of metronidazole and praziquantel. The lump on its nose looks a little flatter, otherwise no change. Still acted alert- distressed at being alone in strange quarters but only showed that by going pale and refusing food. (I didn't offer much, not really expecting it to eat). No clamped fins. At one point I had the fish floating in a plastic bag and when it paused to rest from escape efforts in the corner, I was able to get a very close look at the lump with a magnifying loop. It's not fuzzy. It looks like a white mass inside the nostril, with swollen bubble of skin- a blister?- over that. It was actually pretty cool to see the texture of the fish's skin and colors so detailed- but I still am unsure what this thing is. It doesn't look like any parasite, doesn't look like lympho or air-bubble disease. I guess a cyst. Or some other kind of tumor. Probably not treatable. Nobody else in the main tank has caught it so I am crossing my fingers its not very contagious, and put the fish back home.