They're definately mbuna's so they originate from Lake Malawi (one of the east african Rift Lakes).
Ideally, african cichlids will seek out and breed with their own kind but when their own species is absent in the aquarium they may take the opportunity to hybridize (producing fertile hybrids) with other species (the odds of this occuring, however, depends on several variables).
Also a possibility: sometimes females will release their eggs and moutbrood them (unfertilized) kind of like a ghost spawning. In this scenario the eggs go bad within 3 days and female will ingest or disgard them.