Nice fish, looks more like a Midas to me. Although most of them now are hybrids of Labiatus/Citrinellus. I have six growing on at the moment. Also are you positive it is a male? The reason I ask is that I bought one at roughly the same size as yours, and it had all the traits of a male, long fins slight nuchal hump and even had what looked like male genitalia (small and pointed) So imagine my surprise to come back home one day to find her guarding a huge batch of eggs. She was the only fish in the tank so no mistake on my part, other than thinking she was a he. I have since moved her onto a friend, who has a gentle male, and I am now raising some more. They are only around two inches atm. As for feeding, they usually eat anything, but if after a while you get concerned, try a fresh earthworm. There's not many cichlids I have had that can resist a juicy earthworm. But if you have just got him, give him plenty of time to settle and he will be fine.