Quick Diagnosis of Crook Fish

G'Day All,

Hoping you can lead me in the right direction.

I've lost a couple of fish in my community tank, all patients,
devoloped a light spot on one side, followed by a curving of the
spine, clamping on the tail fins, (they don't fan out wide) they then
become extremely skinny, before dying.

They don't appear stressed, and as soon as I see the tell tale signs
that fish is moved to a hatchery (but still inside the same tank).

All readings pH, nitrates, nitrites, etc are all within spec.... any
ideas?

BTW this is mainly Platys & Mollies that are affected.


thanks,


Ben.