The 1st time I had Paratilapia in the late 80s, I had a trio, of what I thought were a male and two females.
A male and female spawned after a while. The other (what I thought was a female) always stayed on the opposite end of a 6ft tank)
A while later the alpha male died, and within 24 hours (what I thought was a female, drastically changed appearance (forehead profile, darker colors, etc)). It had obviously been a male all along.