Rasbora Het with swollen belly? Help please! I lost a cory already!

[odenata]

Hi all - I just noticed tonight that one of my rasbora hets has a swollen belly.

Here's a picture:

What could be wrong? What should I do? I'm going to go research online more, but I wanted to ask here first.

I'm extra concerned because two days ago when I cleaned my tank, I found what was left of one my peppered cories - the others must have eaten the poor guy. Thing is, I didn't notice any signs of one of them being sick. I watched them all for awhile that day and didn't notice any signs, so this has to have happened in the last two days.

I have a 20 long, planted, water parameters: ammonia 0, nitrites 0, nitrates less than 5ppm. I have 5 rasbora hets, 5 peppered cories (used to be six ) and one neon blue dwarf guarami.

Thank you for any help!

 

[odenata]

Is it possible the fish is carrying eggs and I'm panicking for nothing? All the fish are swimming around happily and seem perfectly healthy...but then there's the case of my poor peppered cory!

 

[Starka]

How long have they been in the tank?

 

[odenata]

How long have they been in the tank?

I've had them all for about six months. I transferred everything (decor, substrate, plants, fish, etc.) from a 20 tall to 20 long at the end of February. Only new thing is plants I put in about two weeks ago:
2 x Large Java Fern
2 x Cryptocoryne Wendtii "red"
2 x Cryptocoryne Retrospiralis, or Spiralis
2 x Anacharis or Anacharis narrow leaf
1 x Marimo Ball
1 medium Amazon Sword
piece of small cholla driftwood
(package from plantedaquariumscentral.com)

(I had plants before that as well, but replaced them with these.)

 

[Starka]

When you changed tanks did you get a nitrite spike at all? Cories don't do well at all with nitrite.
I had switched out gravel with sand in my tank and had a small nitrite spike, a week later one of my cories uped and died.
But your rasbora looks like its carrying to me. Maybe just keep an eye on her to make sure its no internal infection. Like color of the poo, if she's eating, having trouble with swimming. That kinda thing.

 

[odenata]

When you changed tanks did you get a nitrite spike at all? Cories don't do well at all with nitrite.
I had switched out gravel with sand in my tank and had a small nitrite spike, a week later one of my cories uped and died.
But your rasbora looks like its carrying to me. Maybe just keep an eye on her to make sure its no internal infection. Like color of the poo, if she's eating, having trouble with swimming. That kinda thing.

Thanks. I'll keep on eye on her - right now, all those indicators look good (well, except I have no idea about her poo).

I didn't notice any spike, and I monitored it more closely after the transfer. Maybe that will remain a mystery... I can't believe they ate him before I even noticed he died, though! Maybe he was hidden under the driftwood.