what is this fish?
From my book Eyewitness Handbooks - Aquarium Fish, it is a Lemon Cichlid - Neolamprolongus leleupi. Habitat is rocky shallows of Lake Tanganyika. And their temperament is listed as peaceful. I didn't know there were any "peaceful" cichlids. They grow up to 3.5 inches. I'm going to try and attach a scan from the book.
Roxi