Is this the species you have?
I had them a few years back as Tilapia bythobates, from Lake Bermin.
They spawned regularly for me in neutral to moderately hard water, in community tanks, where they ruthlessly guarded fry against larger cichlids. Males reached 7" females 5". They first spawned as small as 3". Mostly vegetarian, too much protein caused bloatish symptoms.
In the above pic, those are eggs on the front glass.