I agree with Madness, looks like it is simply morphing/peeling. If the fish is otherwise eating well & acting normal I wouldn't worry about it. This does not appear to be any type of disease.
It honestly does look like a Paratheraps fenestratus "Lago Catemaco" You can see some other color morphs of the Catemeco fenestratus variant in the link below.
http://www.monsterfishkeepers.com/forums/showthread.php?400569-Paratheraps-fenestratus
Perhaps one ended up in your order by accident - have you checked with the seller?
Thanks I'm checkn now
That was a mouth full. Just keep us updated.