It can be really difficult to tell the difference between the sexes on young pearl gouramies ... as I know to my cost!
To those of you who read the tale of Michael and Mabel/Marty, a few months ago - they are now in a 300 litre tank (as opposed to a 70 litre) with Myrtle and a new female companion: Miriam. They still don't get on - but they don't actually get into fights now. One backs off and retreats to the other end of the tank.
Southern Cross's avatar is a male - long dorsal fin, frilly anal fin and orange colouration.
My avatar is a female - rounded dorsal fin, no frills and not orange.