This species is the exception that justifies the rule. Though it belongs in the same genus with M. auratus and M. chipokae (two of the most aggressive mbuna in this hobby) it is a relatively peaceful species (for an mbuna). I managed to keep two males of this species in my tank (without any females) for six months without deaths. There was a lot of chasing, one fish was clearly a submissive male but still it survived. The males are dark blue with a blue horizontal stripe while the females (recently acquired) are bright yellow as shown in the photo. After the addition of the females there was some aggression between the males which was soon resolved (the submissive male shows no interest in spawning).
This species is a herbivore too and will regularly eat the soft leaf edges of most plants in your tank. Plants that resist the mbuna include Anubia sp., Cryptocorine sp. And Vallisnerias (though some may eat small parts). Grows to about 10 cm (a bit larger in the aquarium). It can be kept in a small species aquarium (one male with 3-4 females in a 90 liter tank). If a second male is desired then the absolute minimum is a 400 liter tank - at least 150 cm long.
Close-up shot: 100 ASA film, 50 mm lens, f/11, 1/60 sec, auto-bellows, Sunpack flash taped over the lens, shot at a distance of 5 cm.
Bottom photo by Aili Pauline McKeen.