I have a pair of blue acaras that I got last week. At the store I bought them at, while watching them in the tank, I was pretty convinced that the two were an established pair. They were guarding a particular area of the tank and many of the other acaras in the tank were somewhat beat up. I was very deliberate in pointing out to the employee which two fish I wanted, and I watched him get the fish out. Now, having them in a tank at home, they appear to both be male. What is the best way to tell if this is true? From research I've done, the best way is supposedly to look at the anal and dorsal fins, both of which should be longer. Is there any other way? If I have two males, I need to take one back. Thanks for the help!