hi
All mbunas can and will crossbreed in a tank,often when my mbunas breed,other males from other species get "crazy" and sneaking,if they can, and dare. so sometimes you can get 20 pure auratus and some" sneaked" juveniles.Try to keep fish who dont are so closed.for exne kind of melanochromis,one kind of metriclima,one kind of pseudotrpheus....and so on. it can be easyer to avoid crossbreeds,but is not an garantee.
all look like crosses to me....
thats why it is important to get quality fish from breeder or places that KNOW what tehy are doing!
NOT the assorted african tank!