I agree about nastiness, the male killed 3 other Ctenchromis, before they were 2.5". These two had an unsuccessful spawn at a very young age, and after a 3 month separation, they are in a 150 gal tank, and I still watch every day, in case I need to rescue her. I believe it helps that the 9 other fish in the tank are 4 times the size of the horei and are distractions.