Banggai Cardinalfish swimming sideways

[Cohenb3568]

I recently bought a Banggai Cardinalfish and noticed that it was swimming sideways and it’s body appeared to be a little bit curved. I was wondering if anyone knew what this could be/ what’s causing it?

PH: 7.8
Ammonia: 0
Nitrite: 0
Nitrate:5.0 ppm


(I tried to take a picture however the fish was hiding between two shells.)

 

[Sniperhank]

By the time you see a fish like this, it is almost always too late. Even moving into a hospital tank can be stressful enough to kill.

Can you tell us more about the system? How old is it? How was the fish acclimated to the system?