Today I noticed that my biggest platy has almost all of his tail missing and I'm not sure what could have done it, I have around a 2 inch opaline female gourami and 2 small rose lines that have been in there for almost a week and a small around 1 inch striped raphael catfish that I put in 2 days ago, all the other platies (15 ish total) don't have any nips at all so it's just kinda weird. Most if not all platies will be gone in a week or 2 but I still don't want aggression in my tank if I choose to add smaller schooling fish. IF you have any idea who the culprit is any suggestions would be great! I was thinking if it's the gourami maybe add a slightly more aggressive fish to make the gourami back down?