Anybody ever tried mixing tropheus cichlids with mbuna in a large tank?
This is a really bad idea for several reasons. First and foremost,
Tropheus and Mbuna occupy the same biological niches in Lakes Tanganyika and Malawi, respectively (in fact, most Mbuna were originally lumped into the catch-all genus,
Pseudotropheus). This is called convergent evolution. If you put
Tropheus and Mbuna together in captivity, they will compete directly for everything- space, food, and a place in the social hierarchy. The problem is, since these fishes evolved independently, they don't share a common language. Thus,
Tropheus and Mbuna can't use body language to communicate, and in particular, they can't communicate that most important message of all (during conflict)- 'I give up.' The best possible outcome here is some very unhappy fishes; a more likely outcome is carnage.
There are other reasons as well, not the least of which is water chemistry. So, bottom line, can it be done- yes, people have done it. But is a mixed colony the best way to keep either Mbuna or
Tropheus? Definitely not.