They can eat any and all of those but you have to watch they dont become a major proportion of the diet, especially if your malawis are primarily algae browsers, or the excess fats and protiens can cause hepatic lipidosis and gastrointestinal distress, the result of that being whats commonly known "malawi bloat" , which is basically dietarily induced dropsy, except that malawi keepers love to give things "special" names lol.
If you mention the species I should be able to come up with something more specific on how suitable the foods may or may not be.
Sorry for the late answer, forgot to get to it, I wanted to doublecheck references.
1)nimbochromis livingstoni- carnivore omnivore, can probably be fed like any other primarily c/o fish, comperable to the south american fish, minimal dietary dropsy risk, likes the protien.
2) melanochromis cyaneorhabdos - micropredator and opportunist, probably should limit the livefoods to less than 20 % the diet and rely on microfauna and decent cichlid pellets for the diet primary with shellfish and prawns for backups.
3)metriaclima callainos, prev pseudotropheus - primarily vegetarian, algae browser, mild opportunist streak- malawi bloat risk, needs diet governed so that livefoods represent less than 5% . Primary diet would be veggies, spiriluna sheets, cichlid excel, veg flakes.
4)metriaclima estherae - micropredator/ opportunist, known to be prone to obesity, keep the diet varied and lean. People recommend cyclops etc. Considered another bloat risk, this fish will pile on weight if allowed.
5)pseudotropheus demasoni - vegetarian primarily, another dropsy risk , another that needsthe livefood amount severely limited. Cichlid excel as a staple would be good, veggie treats.
6)pseudotropheus saulosi - same as the demasoni really, any livefoods should be at most irrelgular isolated treat items, not regular diet. Protien content in nature would be handled mostly by microfoods.
7)astatotilapia latifasciata- the victorian in the malawi tank,- true omnivore, predatory leanings, minimal dropsy risk, will love the livefoods, and has been known to fin and scale nip predationally. Might have to watch that one in terms of community compatability, but not a big risk on dropsy.
If you really want to control that feeding situation you'll be better off with the venestus and the astatotilapia away from the regular malawis. In trying to feed them the protien they love, you could cause the malawis some problems with dietary fat. Depends on some extent on the feeding behaviour you see though, If the venestus and the astato dominate the protien leaving little for the others then no foul, if however they are slow and the other malawis take advantage, you'll get issues. Just use your best judgement.
thanks for the reply - really helpful. Apologies for the lateness myself but have been on hols!
The astatos are already a good size and are pretty much first in line for the regular food - surprising as i always heard it would be the opposite and that the victoria cichlids would be last in the queue when mixed with malawis...
i think what i'll do is try a block or two and see which ones take the most, keeping an eye on the veggies.