African cichlids

@Chlidonias Sherlock Holmes would have said that this is a three pipe problem: I will need a little time

I have downloaded both of these photos, so that I can examine them at full size. The first thing to say is that they all appear to be from Lake Malawi. Moreover there don't seem to be any of the larger haplochromine cichlids found in open water and over sandy habitats (the utaka). These are all the moderate to medium sized mbuna which live rocky areas of the Lake.
Some of the mbuna are quite distinctive, such as the large Petrochromis species and the wasp cichlid Pseudotropheus crabro, the Labeotropheus species with wide upper lips, the horizontally striped Melanochromis species and the small, narrow-bodied Labidochromis species. Unfortunately, I can't see any of them in the photos
So I agree with @Chlidonias that we have a number of species that were once called Pseudotropheus zebra, and several more that resemble them in body form and frequently in colour pattern too. I will now start looking them up. I have a few ideas to check, but I won't be able to identify those brownish, slightly stripy juveniles - some of which might even be hybrids. Don't hold your breath

OK, I have some answers which might be correct.
Starting from the centre of the photo above, the two pale pink males a little way out at about 4 o'clock and 8 o'clock are probably Maylandia esterae from Minos Reef, a distinctive race of the red zebra, the females are not red either, they are the bright orange-yellow fishes scattered through the tank.
The plainish pale blue fish with orange dorsals and more orange in the top half of the caudal at 2, 5 and half-hidden at 7 o'clock (with more further out) are probably males of another member of the zebra group, Maylandia greshakei from Makola Reef; the females of this species/subspecies/race/morph are plain dark brown, so there seem to be plenty of those in the tank.
Another species which I suspect may be there is the rusty cichlid Iodotropheus sprengerae,which also has dark red-brown females , but I can't be sure as I can't see a male in either photo. Adult males are also dark, but have purple sheen in good light; they are said to be less boisterous than most Malawis, so might not be showing.
I haven't been able to identify the plain blue male with dark dorsal, caudal and anal fins near the centre at 5 o'clock. Neither have I been to match the rather smaller male with slimmer body plus blue and black bars (which cichlid keepers call BB) half way out at 9 o'clock - I suspect that it may be a form of Cynotilapia 'elongatus', but that group is even more confusing than the zebras.
I'm afraid I'm not a expert on Malawis, as I used to specialise in Tanganyikan cichlids, and identification from photos is never easy. If anyone is interested in identifying Malawi cichlids, I recommend the website malawi.si I presume that the text is in Slovene and I don't understand a word of it, but it has hundreds of photos of Malawis, mostly taken in the Lake by Ad Konings, the most experienced scientist working with African cichlids.

Correction: in my second post above, I referred to the genus Petrochromis, which is actually from Lake Tanganyika. I should have typed Petrotilapia, which is the ecologically equivalent genus in Lake Malawi.
It is easy to get confused by African cichlids, but their similarities and differences are what makes them so interesting.