hmmm maybe you have to wait a lil while longer until it completley matures. u are right it looks female becuase its mostly blue but i do see some yellow as well so thats why i say to wait and see whats the outcome

but it is rather large; looks fully grown to me already. This picture does not show how big this fish really is. I will try to get a close up of it later and send it in for everyone to see amd post comments.

I have a feeling it may be a male. Just looking at the body shape, my males are very aggressive, has this one shown any aggression yet?

Not really what I would call aggressive. It is more like it will not allow other fish in its little territory or space. I just thought that it was a female because it has a big belly and it has touches of yellow color on its belly, fins, and tail. It seems to be fully grown so I am just not really sure of the sex yet. I will take a close-up pic later and send it in so u all can give me your opinion of what sex it is.