Fish swims vertically, gas bubble protruding under skin, growth defect.

[confused_aquarist]

Hi, I have a killifish fry that looks like below born with a big air bubble above a bloody patch on its side. For weeks it lay under the bottom of the tank sideways so I isolated in a paper cup and to my surprise grew up just fine in it. The picture was taken at 1 month old and since then it started swimming near surface but only vertically and its growth is much slower than other fish. It’s at 3 month old now, has normal appetite, can breed, and still has the air bubble protruding from under skin and still swims vertically for the most part.

In the picture though with bad quality you could still see hemorrhage (dark red patch) in the muscle/somewhere under the skin/on one of the internal organs, and actually an air bubble is protruding from where the hemorrhage is. I’m wondering what is going on or if anyone has experienced anything similar. Not sure if I should isolate this individual if infectious.

 

[GaryE]

I find about one in ten of my captive bred normani fry develops a similar pattern. I view it as a developmental defect. I don't see the bleed or the bubble, but I do see the swimming problems.
Hobby lore says it's a problem with inflation of the swim bladder after hatching. I have never seen a concrete study/look at it.
Curiously, I bred wild caught normani for about 10 years, and in the many hundreds of fry, never saw this.
The issue becomes one of how you think about culling. My 2 normani like this are in the group, and I doubt they'll live long. If they do, they won't be put into breeding set ups.

 

[confused_aquarist]

I find about one in ten of my captive bred normani fry develops a similar pattern. I view it as a developmental defect. I don't see the bleed or the bubble, but I do see the swimming problems.
Hobby lore says it's a problem with inflation of the swim bladder after hatching. I have never seen a concrete study/look at it.
Curiously, I bred wild caught normani for about 10 years, and in the many hundreds of fry, never saw this.
The issue becomes one of how you think about culling. My 2 normani like this are in the group, and I doubt they'll live long. If they do, they won't be put into breeding set ups.

They are indeed captive bred.
This individual actually used to have an attitude, except now is being chased around due to being outgrown. Sad because everything does seem normal except for the swimming.
My killies never hatch inside the tank, the eggs literally get eaten a few minutes after being laid. In fact I've always wondered why some people could see fry in their tank because they would search anywhere to find eggs to eat. I've been breeding them because I'm too afraid the eggs might clog up (it's a female).
So since the eggs are getting eaten I guess if it's bacterial then isolating would be too late anyway, oops.

 

[GaryE]

It could be bacterial, but if it's like what I have seen, it's one of those you stay well and I get sick situations. It happens early in the life of the fish. I've never seen it spread.

You have annulatus, right? I've seen it with Poropanchax recently, but in the past with a small percentage of Epiplatys, Procatopus, Platopochilus and Aphyosemion. I just take it as a misfortune that affects a tiny percentage of fry. I've never been able to establish a pattern, and it has never affected my ability to keep species going.

With annual killies, you can have large numbers incapacitated by swim bladder/"belly slider" issues, but non annuals are less hit by it.

 

[confused_aquarist]

It could be bacterial, but if it's like what I have seen, it's one of those you stay well and I get sick situations. It happens early in the life of the fish. I've never seen it spread.

You have annulatus, right? I've seen it with Poropanchax recently, but in the past with a small percentage of Epiplatys, Procatopus, Platopochilus and Aphyosemion. I just take it as a misfortune that affects a tiny percentage of fry. I've never been able to establish a pattern, and it has never affected my ability to keep species going.

With annual killies, you can have large numbers incapacitated by swim bladder/"belly slider" issues, but non annuals are less hit by it.

It's annulatus. At first I also thought this was a belly slider, but it didn't really make sense, the fry just seemed to have a huge cyst attached to it at first, maybe 1/3 of its body size. I thought it was a tumour, but it never grew at all and then it located to the right side of its belly. Where the lateral line would be. For now I'm just assuming that it's a case of gas bubble disease that developed inside the egg, though I'm not sure.

 

[GaryE]

It might be an defective swim bladder, maybe with too weak a wall? If it over inflated when the fish was young and the musculature wasn't developed to restrain it, it could technically stay large. That's pure speculation.
I'm thinking of a hernia-like structure.
The poor fish.

 

[confused_aquarist]

Oh my gosh! I hope not. I did think about the possibility of it being a swim bladder but that would be in such a strange location though still plausible.

I did find a footage of it (it's the one above the sponge filter, again bad quality), where you could see a shiny little bubble on its side between those black stripes. It appears as a bump seen from the front. I do hope it won’t injure itself if it turns out to be swim bladder, the bubble is literally under a single layer of skin

Another thing which I took note of while googling is that it definitely also seems to have a gaping hole in the middle of its chest from which it defecates. I always thought that it was the anus, but it isn't and it's apparently called a fistula.