One of my Oscars (7") seems to have taken a beating overnight. There are 4 Oscars in a 1000ltr tank - ranging from 6" to 13". They are gentle giants normally. Occasionally they 'mouth' each other, but there has never been any real problems. However, the mouth on one of the babies seems to have been 'dislocated'. It doesn't appear to affect him at all. He is eating and being his usual self. Any suggestions of how I can help him out?