Like other typical 'tilapias', it has relatively small closely packed teeth, numerous gill rakers and juveniles have a dark 'tilapia spot' at the base of the soft-rayed part of the dorsal fin.

Like other members of the subgenus Nyasalapia, the mature males develop a long, branched genital tassel and construct complex display structures or bowers on the bottom mud, characterised by a raised central platform, in contrast to the simple saucer-shaped pits excavated by other Oreochromis.

A small proportion of individuals of both sexes, although mainly females, show a disrupted melanin distribution, resulting in a pale orange or whitish fish with irregular dark blotches on the fins and body.

Oreochromis variabilis also has a rather distinctive head profile, with a 'bump' just above the eyes, rather like the Lake Malawi 'chambo' species (males of which lack red fin margins), but less strongly expressed in O. rukwaensis and O.

Males are conspicuously coloured and aggregate in shallow waters, where they aggressively defend territories centred around their courtship bower.

[4] The species is listed as near threatened by IUCN, with population declines attributed to the introduction of predatory Nile perch and competing non-native tilapias.