Unless the world has changed more than I thought possible, Mojo keeps mostly Central American cichlids, which wouldn't make good tank mates for the mild tempered mbuna varieties the OP seems interested in
I am keeping mostly Tanganyikans, but a Malawi species I have really enjoyed is
Metriaclima lanisticola.
They are amongst the least aggressive mbuna I have kept - similar to rusties and yellow labs. The fish are sometimes referred to as 'Malawi Shell Dwellers', but the adults of my colony showed no interest whatsoever in shells, pipes or caves. Only about 1/3 of the fry were shell dwelling at a young age. Curiously, the other 2/3 of the fry preferred to hide in floating plants at the top of the tank! I kept them in a 75G with a colony of yellow labs. I am sure they would do fine in a much smaller tank, but I am thinking my colony was fairly old and the dominant male was a big fish as far as mbuna go.
Last but not least, I believe M. lanisticola is the only mbuna species for which it has been proven that they can do a complete sex change! No kidding, Dr. Jay Stauffer was able to show this in a peer-reviewed, scientific paper! In a nutshell, his research group took proven females, that is fish that had laid eggs and carried them in their mouth, and put them in a separate tank. Eventually breeding was observed and fry were obtained from a tank containing only such proven females. This shows that at least one fully functional female had turned into a fully functional male. If you are interested in the paper itself, it is available
here. The paper refers to the fish as M. livingstoni, which is an old name for M. lanisticola.
