I have 2 angels in my overcrowded angel tank that appeared to have paired up. They are on one side of the tank, cleaning the glass, only straying to eat or chase off one of the other angels. Both of their breeding tubes are down. I'm just wondering as to what is the best way to figure out which is male and which is female? One tends to do more of the cleaning while the other one is busier chasing every one else. One also has more of a taller dorsal fin. Their tubes both look male to me, but I'm sure I'm wrong cuz I can't see 2 males hooking up