I have a group of 6 ranging in size from 6-8 inches and was trying to find out the best way to determine the sexes of them. Once I get that figured out, i'll plan on seperating a pair.
Okay, simple... See their dorsal fin. The males have a pointed, elongated dorsal fin. The females' dorsal would tend to be shorter, & rounded. Last note, males tend to be aggressive on one another, occasionally.