Definitely a male. Dont worry about the rounded fins. My guy in my avatar didnt start to grow his out until after 4-4.5 inches. It actually gives you something to look forward to. My other male that i had to rehome didnt grow his until about 5 inches. I also started my tank out with a GT and a JD. As the GT out grew the JD, the GT would chase the JD relentlessly. I no longer see my JD on an everyday basis, He hides in a hole inside one of my fake ornaments and never comes out. Ill see him about 2 times a week if he hears the food drop in the tank. Just keep that in mind.