I bought some Guianacara last year as the species geayi, but because of the "small spots in the dorsal, and because they exhibit a vertical stripe on the center of the body on and below the lateral line" (Weidner: South American Eartheaters)
it was pointed out that they are probably more likely owroewefi.
At times the dominant males will lose all dark markings, while females retain them.
When I first obtained 20 of them, they were 2" or less.
The 10 I have now are around 4".
They have spawned at least once that I know of, very secretive, they dig caves under wood or rock. The eggs are dark green and were defended well, but it was a very active community so I never saw fry. There are eggs in between the pieces of wood below, as you can see, the parents were still small, when the spawning occurred.
The Guinacara have been fairly non aggressive with other cichlids larger and smaller, in fact I have been using them as targets them to suppress con specific aggression among other volatile species.
The sheer bulk, but yet non aggressive nature of the Guianacara, seem to intimidate, and focus attention of the other species elsewhere.