Red-eyed Tetra w/red buldge on side??

[Exevious]

I noticed one of my red-eyed tetra has a swollen section on his side.. It appears slightly redish...

Not sure if he got beat on .... or if its a disease.

 

[Exevious]

I managed to catch him....

his whole belly was swollen.. and it looked as if it were busting open!

he is freezing as we speak...

I hope it doesnt show up in any of my other fish.

Any idea what it might be?

 

[Exevious]

Red eye #2 is in the freezer....

Signs of slight buldging and redness... not near the same, but I dont want to take a chance.

So far no signs of anything with the other fish.

 

[Exevious]

OK.. this is getting insane...

I just took out a dead glowlight, lab fry, and danio....

no signs of illness, not sure if I might have hit them chasing the sick red-eye...
I did a water change after I removed the sick red-eyed.

But other than that nothing has changed with the system.