It sounds then that whatever problems ray(s) were having were related to the catfish illness. I mean the cause is likely the same or similar. I must retract my initial thought of a ray-induced injury.
Assuming that the water is pristine and stable, this sequence rather points to a pathogen that these very different fish shared. But with the symptoms as described above, it's a shot in the dark as to what that pathogen might be. One thing you could attempt to figure out is where the pathogen could come from. That may or may not help figure out what it might be.
Which then in turn may help pick a medication or a few to experiment with.
Assuming that the water is pristine and stable, this sequence rather points to a pathogen that these very different fish shared. But with the symptoms as described above, it's a shot in the dark as to what that pathogen might be. One thing you could attempt to figure out is where the pathogen could come from. That may or may not help figure out what it might be.
Which then in turn may help pick a medication or a few to experiment with.