As angelfish become sexually mature, they also become territorial and aggressive. Eventually, you may get a spawning pair, and they will intimidate their tank mates sometimes to the point of causing death. A spawning pair can also be quite aggressive with each other. Right now in a 45 gallon tank, I have a newly formed pair of angelfish, 20 or 30 of their babies, and three more mature angelfish hiding in some plastic plants. I'm going to remove some of the plants so I can catch the extra, mature angelfish and transfer them to another tank. That's not going to be easy, and in fact raising angelfish is not always easy. On the other hand, angelfish are always fascinating and worth the extra effort....if you're a nut like me.
