although most mbuna are omnivores(eat everything), albeit, omnivores which require a lot of vegetable matter in their diets--some of them, like the labidochromis and iodotropheus need more protein. the labs are insectivores and the rusties are micropredators like tangs(i, think--gotta double-check this part). so they make good tankmates for haplochromines, not only because of temperament, but also because of similar diet.

you must do your own research, however...i found numerous sites that refer to these fish as herbivores; as a matter of fact, many people believe that all mbuna are herbivores(vegetarians). off hand, the only herbivores from lake malawi that i can think of are the labeotropheus--most of the mbuna are omnivores, omnivores which happen to need a large percentage of vegetable matter in their diets.

EDIT:i have to revise this post somewhat...i thought that all labidochromis species were insectivores---wrong!! some of them lean heavily towards the veggie side like the pseudotropheus. some of the meat-eaters(insectivores) are: l. caeruleus, chisumulae, masinje, maculicauda, ianthinus, and sp. blue bar. the rest of them seem to be algae grazers that take in some occasional protein that occurs in the aufwuchs.

I'm surprised you didn't mention the bumble bees, Maylandia crabro. Fish lice eaters.

jonah, dear--if you scroll up, you'll see that i didn't mention them because you already had in an earlier post. :P also, remember melanochromis parallelus eats fungus and parasites off the bodies of utaka and other non-mbuna.

oh--i did forget about that nasty genyochromis mento that eats other fishes' scales.