Since you posted the same question in the Media lounge and in the maine section I merged the two threads here so you wouldn't loose any posts from either thread. In the futrue please make only one thread, if it's in the wrong place we'll move to where it belongs. Thanks.
Some type of Amphilophus sp. or combination there of. Did you purchase the fish with out knowing what it was?
In the future you should always ask what it is first and reasearch it's care requirements before purchasing it. Find out how big it grows, what size tank it needs, it's level of agression and weather or not it will get along with your current stock also you need to know if it has any special dietary requirements or special/different water parametes for your current set-up. There are many questions that should be asked before makeing a purchase. So please keep these things in mine before taking in a new fish.