Anyone ever had these guys beat each other up? About once a week one one of my rainbows (The second largest I think) gets kind of beat up by the largest (I assume, haven't actually seen it) It then hangs out in the Vals by the filter a lot for a few days, and starts looking better, comes out again and then a couple days later the same thing seems to happen. The damage isn't terrible but it is definitely noticeable and this has been happening consistently for at least a month. I have never experienced this type of bullying in schooling fish before, even with supposedly nippy schoolers like Tiger barbs, serpaes, etc. The rainbows (there are 5) are in a 55g with many other fish, including small ones like neons, otos, ect., and they never bother anyone except maybe when I first introduce a new fish they think I'm feeding them and chase the "food" around for a bit till they realized their stomachs fooled them
(they are huge pigs).
I'm guessing this is a dominance issue having to do with genders? I have read that males are deeper bodied than females, so I assume my largest one is a male, but I also read that females are uncommon in the hobby, so I assumed I had all males, and that the biggest one was just, well, bigger. Is this likely or do I probably have males and females and my one guy is getting beat up because he is the odd man out?