pacu and unknown fish

Red Devil

I was going to say Midas Cichlid (A. citrinellus).

Also it sounds like in America (and elsewhere, I guess) hybrids between the two are commonplace in the pet trade.

@Chlidonias Yeah hybrids are indeed frequent, which complicates things. Both species can display the white blotching, and the normal forms look pretty similar. Some people apparently lump the two together even.
Looking at how to tell the two apart, I'm still thinking Red Devil as the lips seem fairly distinct.

thanks again