Disease?

[Nilrem]

I had five Diamond Tetra in a 100 gal tank two of the Diamonds this morning are dead two days ago I noticed they looked like something bit there mouths off. Also in this tank are three Mollies, six Neon Tetras 12 Boesemani Rainbows, two Paradise Gouramis, one pleco, one bamboo shrimp and possibly a fresh water crab( she hides not seen in a few days). Is this a possible disease I saw something like this in a store with only community fish in it. If it is a disease what is it? How do I treat it?

 

[Mumma.of.two]

I'm not saying it is, but mouth/lips missing shouts Columnaris to me. Might be worth researching.

 

[Nilrem]

Thanks for the help. I was worried about that will look into it

 

[Autumnsky]

Any updates?