I have two angels about quarter size. When I got the first set (one of which didn't make it) I chose them based on the gender characteristics. The marble had male characteristics and the deceased zebra had female characteristics. I went to get a second angel and brought home a gold angel who had been at the store for over a month. This one also had female characteristics and had at some point been beaten up pretty bad (had a torn dorsal and a short ventral; dorsal is still looking torn but much better than before and ventral is almost fully grown back). The question I have is when might I start being able to see their breeding tubes. I looked at them closely today and it looks like they're out and visible on both of them. If that's the case I do in fact have a male marble and female gold. They swim together much of the time and appear to get along really well. I'm hoping they'll become a breeding pair.