I do not think the fish is stressed. It was very pale when I bought it 4 weeks ago and now its gaining lots of colors. Its length is about 4'' long and it was not even 3'' when I bought it. It's alone in a 55 G tank, and i have no plan to upgrade my tank for now so the fish should stay in this tank alone. I added plants and terra cotta pots so the fish can hide in them, and so far he/she didn't mess them up. I will post more picture. So thank you for your answers, it should be a female then? It's my first JD, I only had angel fish before...