Sorry to spoil the fun, but its not a black. Definitely a silver. My first aro used to look like that. Its a very beautiful silver so don't get me wrong. Black arowanas don't have orange striping on the tails. They do have a orange/red edge on their fins, but the majority of the fins towards the inside are black and then its clear as you get closer to the body. Beautiful fish though, Good Luck with him! 
