Just to confuse things, acara can be a generic for any of the fish once described as Aequidens sp. and there may be 2 or 3 "green terrors". http://cichlid-forum.com/profiles/category.php?cat=24 Juvies look quite different from adults so it can be hard to identify them.
I have 2 acaras and they are very difficult to tell the difference especially when so young, gt's have a thicker band on their tail and a more pronounced hump on the head.
does look remarkably similar to mine, wait till it gets to about 3"+ and it will be easier to tell