I realize this is an old thread but I have to say, I'm more upset that the OP didn't research the fish before buying it more than it not being in the proper tank size for when it hopefully eventually reaches maturity. These animals are not cheap so why for heaven's sake would you plunk down that kind of cash blind? It sounds to me like the store he got it from didn't take the time to educate him either. Double blame from my aspect (and I'm a former retailer!!!)
People, listen up!! RESEARCH YOUR PURCHASES BEFORE YOU BUY THEM!! In today's world, you can google anything right from the shop before you decide to buy it. If you need to ask "ID this for me please" on this or any site, it shouldn't be in your tank yet. You wouldn't do that for a car, or a horse, or a snake after you buy it would you? Don't do it on a fish either.
I now relinquish my soap box.