I've seen lots of small young in aquarium shops so be prepared for the possibility that it is fertile and breeds true. However, it is probably in the top 20 biggest selling cichlids in the UK aquarium trade, so there's a lot of them about. The only information on this fish is likely to be in fishkeeping journals. There are no worthwhile keys of African cichlids, as about half of them are undescribed. M. 'exasperatus' is a synonym of M. joanjohnsonae.
Males are metallic blue, sometimes with faint vertical bars.
The dorsal fin in paler with a broad black horizontal stripe. The anal fin is yellowish and the dorsal has a horizontal black band like the male, and usually a thin red upper margin. It is rather similar to several species currently placed in Labidochromis, and it is there rather than Melanochromis that its affinities surely lie. It has been placed in Melanchromis purely on the basis of its having bicuspid teeth, rather than unicuspid. Other possibilities are various Labidochromis spp.