pulled upper lip

Hi Guys

My one new angel seems to have a pulled upper lip, there is a membrane above lip that moves in and out with breathing. It also seems to have difficulty eating, and is skinnier than the other one. Is this because of lip locking? Can I do anything about it?

Thanks
Thinus

Angels have an extendable mouth, on occasion it can stick open. Usually the fish manages to sort it without intervention, but not always. I have heard of cases where people have gently manipulated it back into place for the fish, but it's not something I'd want to try! It could have resulted from lip locking, but not necessarily. Ideally I'd keep him in a separate tank so that he's not bullied, and keep my fingers crossed for him.