Well, it looked like it could happen, and it has. I have been noticing unusual behaviour in my 2 Koi Angelfish recently, and found out that it was their courting ritual. They were fighting and chasing each other. Then, while I was sitting at my PC just 5 mins ago, I saw them laying eggs on a leaf. It is amazing, see how they so carefully work together after all the fighting. The female swam up laying a line of eggs, followed instantly by the male who fertilised them. I hope they manage to hatch a few off the eggs, so I can watch them being raised. That would be amazing. 