It is extremely hard to tell male from female with this species. You cant go by size of head hump or size of fish or blue coloration or fin extentions. Once they start to mature you might be able to tell one male out of the group by which one is bossy to the others, might be your alpha male if you have a mixed group. The alpha male might grow bigger sooner and could show darker or different coloration compared to the others (from moodyness i think LOL). Bottom line is there are no sure ways to tell with out sexing them. I just had the one so I had nothing to compare him to. He sure was a pretty blue, i call it a he but who knows LOL. Hope that helps, you will likely have to wait till they do the deed LOL.
