blue chromis mouth stuck

[Invictus]

One of my blue chromis has their mouth stuck open, it almost looks like it may be that way because of rot, but I couldn't get a good look because he darted into the rocks. It also looked as if he was breathing harder than normal, ie the gills were opening very wide.

Can saltwater fish contract a mouth rot of some sort? I haven't been able to find anything by searching online. Only for freshwater mouth rot.

Nitrates and nitrites are higher than normal and I'm in the process of trying to lower those.

 

[Invictus]

The fish actually died, but I got it out and it looks like the area around its mouth was clear or deteriorated. Nothing was stuck in its mouth.

No ideas on what this is?

 

[Ethan Music]

sorry to hear im clueless if you ever find out please let us know.