L128 spawned - fry got blister belly

[AndersB]

Hi

I had success making my group of L128 spawn

There were 23 fry, but all but two died. It seems that their yolk sack wasnt consumed - the fry grew and got colour, but the belly looked like there was a pea inside of it.

Just two of the fry didnt have the "blister belly", and they look nice and healthy so far. They have consumed their yolk sack and have started eating. They are around 1½ cm now.

Does anybody know what causes such a swollen belly on fry? Or knows what to do to avoid fry getting so swollen?

[AndersB]

Here is a Picture taken with mobile phone

L128 fry

[jac]

Most likely a bacterial problem. At least that was what I was told.
Some of my fry had this:

[AndersB]

Thank you for your answer.
I was thinking bacteria as well, so i have been cleaning sides and bottom of the tank daily. I even used a uv-filter.

How do I avoid it happening again?

[7Pete]

Meaty diet? I mean too much fat in food. That's common symptom and killer for older omnivore plecos too.

[AndersB]

Thank you for your answer. It could be the diet, but the fry didnt even make it to eating before they died. The parent fish are fed primarily vegetable with a bit of protein - pellets and sometimes frozen food

[Linus_Cello]

What is the TDS? Is it still too high that this was a problem back in the egg development stage?

[AndersB]

TDS was about 80 or 90 ppm when the eggs were spawned. I didnt change water or feed the adult fish in an attempt to keep water parameters as stable as possible.

[Barbie]

In my L260, I determined the cause of that was low dissolved oxygen. Because of the increased temperature and the small containers I put the fry in, even a small amount of disruption in flow would cause this issue. I also had not fed the fry yet when I had them do this.

Barbie

[AndersB]

Thanks for your interesting answer Barbie. I havent thought on oxygen as an issue. But maybe that is the problem. After they hatched I kept the wigglers in a small container hanging on the side of the aquarium. The small container had water circulating from the aquarium via an air tube(I dont know what it is called in english). I also added an air stone to the small container.

Before the yolk sack was consumed I moved the fry to an 85 liters aquarium. Also with an air stone and a filter driven by air. Dispite that, maybe the drop in dissolved oxygen caused the problem.

Any tips on how to dissolve oxygen in aquariums other than air stones or air pipes?

[Barbie]

I just use increased flow and a small drop in temperature. Basically I make sure the water flowing through their container is brisk.

Barbie

[AndersB]

Hmm just like me except I dont decrease temperature.

[Barbie]

It is entirely possible that the cause for mine was not dissolved oxygen, but something else I didn't realize. I just know that when I changed the way the water flow through the condo was generated, so it didn't slowly reduce over time, the bubble bellies stopped. The yolk actually turns more opaque on them and I could notice it happening before they ever started to swell. I was also told it can be caused by introducing food before they are done absorbing the yolk, which I don't do, but that could also contribute to the lower dissolved oxygen, for that matter. How much surface area in the boxes you keep them in? I also keep a small piece of driftwood in each for them to grasp and hide around on.

I do know that on the fry I lost like this there were no discernible parasites present, for what that is worth.

Barbie

[AndersB]

The surface area in the box is 10x20 cm, with a good water flow of water from the aquarium they were spawned in plus an air stone for extra air supply.

I also experienced it was possible to spot the ones which would get the bubble belly, and all of those died.

If they spawn again I will let the male hatch the eggs or keep the wigglers in the small container until they are ready to eat.

I really appreciate your advice - so thanks to all contributors