I have a new convict cichlid which has lost a piece of her pelvic fin in a tussel with another fish. Will this fin regrow or will it remain permanently damaged?
Fins will regrow, but it takes time. As long as the torn fin shows no sign of bleeding, infection or fungus, in a clean water invironment and with good food, she should be fine.
But if she lost her fin to a tankmate, you should reexamine your mix of fish, because if she was attacked once, it may well happen again.