I have recently read several articles on sexing and raising Banggai
it seems that males are a little bigger with a fuller bottom jaw, with a longer second dorsal fin (if I recall correctly) while the femail has a more rounded almond shaped body. The author also said that this is not fool-proof so he sexes his fis by dropping one in the tank with a known male and seeing if they get along. I will try to find the link for you.
