I have noticed that on one of my danios is tale is looked like it has been nipped at. I have two serpae tetras in my tank I was wanting to know if it could be one of the tetras or another danio. Now that I think about it I have seem the bigger danio chasing him around a lot more. I have 2 black mollies and their tales don't seem to be nipped at all. I was wondering what I should do with the danio that is getting his fins nipped to help him heal and to stop this fin nipping. Thanks.