I'd say 2.3 to 2.5" just got it few days ago. My other one doesnt have any yellow.How big is it? I'd say female at this point, unless it is less than 2.5" Males will get much more red/orange to the front and as they get larger, they get larger (hump behind the head start to develop and their bodies get deeper as well)
Male - females have horizontal stripes.
Keep the ideas coming guys.here the side by side picture. I only got two for now when I know wich one is male or female I will go back to get more female so he have more then one choice.I vote female, males have a much more rounded body like a hump like this