Looks like a blue zebra to me, we used to call them BB zebras or Red-topped BB zebras if the dorsal fins where red/yellow color. Now reclassified as Red Top Zebras (Metriaclima pyrsonotos). Distinguishing between the Metriaclima and the cynotilapia can be difficult, especially with ones that have not reached full size. If they came out of a tank of mixed Africans, they are more likely Metriaclima than Cynotilapia.