I had two of these little fishes in my tank and I believed they were both males because they were very territorial towards each other (but peaceful in general). After awhile the smaller one was dead under my drift wood. Although I've seen the LSF having numerous amounts of these guys in a medium sized tank with other small fishes, my tank was only 12 gallons. They are sometimes called Chameleon fishes because they had the ability to slightly (not fully) change color depending on there "emotions".
Mike