Its basically survival of the fittest. The weaker ones are not going to end up making it. I don't mean that one day you will just find him dead, the other fish are just doing what they would do in the wild. There is a reason do don't see fish with broken fins and a bent tail in a pond or lake. Right now the male is strong enough to fend for himself but over time he may get weaker due to the constant harassment and the wound on his back. I would definitely move the fry to another tank (you should always have the fry separate from the parents). Give the male some time by himself, keep and eye on the wound, and he should start getting better. Do water changes often in his tank so bacteria does not start getting into the wound. When the wound heals you could introduce him back with the matured fry.
