Neon Tetra Acting Strange Part 2

[confusion]

I took my dead black neon back today and got a few more - I was down to 2, so I bought 4 more to get them up to a good school of 6. After dinner today, I noticed that one of them was not schooling with the others, instead staying by himself in the middle of the tank at the top, with all of the others zipping by. My danios would occasionally stop and give him a nudge to get moving and he would swim for a short time, but then go back to hovering. When I fed them, he did not eat. He did go up to the surface acting like he was going to take a bite, but he got a gulp of air instead. Subsequently, he would make a motion to the top, as though he were going to eat, but never did.

His mouth is opening and closing pretty frantically, but not in synch with his gills - his gills seem to be working at a normal pace. His black band is somewhat faded, but then so are a few of the other very active and hungry black neons I have.

Unlike the last one, this one is not showing any signs like cloudy eyes, etc.

I've read frequent accounts in the many internet boards about people losing an average of one neon every time they buy a batch.

I've read all about NTD, and so far, I'm hopeful that this is not the case.

I think I'll probably take him back to the store tomorrow if he's not markedly better. Any ideas what this could be?

The important numbers:
55G cycled tank
0 ammonia
0 nitrites
~0 nitrates (well planted)
tank mates: 7 zebra danios, 6 black neon tetras, 19 swordtail fry, 5 rosy tetras and 2 common plecos.

 

[confusion]

So, I found him hiding behind the filter discharge. He was seemingly swimming normally, but if disturbed, he couldn't right himself easily. I netted him out and put him in a bucket with clean, dechlor. water. I put in some maracyn 2 and an air stone. He swam around for a few minutes and died.

I'm not having such good luck with my black neons.

 

[fish_fetish65]

neons are rather frail little creatures. you do usually lose one whenever you buy a batch, as one of them is bound to go into shock or something of the sort.

sorry about your fish... at least you have a nice school of five

 

[WILDER]

They are quite hardy fish, i would try another lfs, sounds like he black neons in the lfs are not a good healthy batch.