Tropheus duboisi from Lake Tanganyika. This species lays very large eggs, which are incubated by the female for much longer than most mouthbrooding cichlids, because the female can actually feed a little while brooding. The fry are very large when released. The female is the upper fish in this photo, the male guards the egg until she turns to pick it up, then the pair change places and the male releases sperm to fertilise the egg in the female's mouth.
