It's called Dimidiochromis compressiceps
and they are fine with mbuna as long as the mbuna are large enough not to fit in their mouths.They are predators through and through and very quick.The chances of fry surviving in a tank with eye biters in is pretty much zero.10" is the maximum length.The trouble is that. A third of their 10" is all mouth.They are mouth brooders and can hold a large number of fry sometimes up to 150 at a time.They like tall plants to wait in ambush for prey.Generally they hang around the upper regions of the tank.
A very beautiful fish IMO and a great addition to a tank.Males are a beautiful metallic blue with orange dorsal and anal fins.Females are silver with a brown stripe laterally down the body.