Melanochromis johannii

Melanochromis johannii, the Electric Blue Johanni, is celebrated for producing one of the most dramatic cases of sexual colour dimorphism in freshwater fish. Males are a vivid electric blue with a contrasting black dorsal fin and black horizontal stripe, while females are a warm golden-orange with fine dark markings. Interestingly, females can sometimes change colour and temporarily adopt male-like blue colouration.

Native to the eastern shore of Lake Malawi from Mozambique, M. johannii inhabits shallow rocky zones where it aggressively defends feeding territories. Like other Melanochromis, it is primarily herbivorous and grazes extensively on aufwuchs. The species is robust, adaptable, and hardy, tolerating a wider range of water conditions than more sensitive cichlids.

In the aquarium, the Johanni is a classic mbuna species well suited to beginners willing to manage cichlid aggression. Provide a heavily decorated tank with abundant rockwork and keep a single male with multiple females. The contrasting colours of the sexes create an exceptionally attractive display that has kept this species popular for decades.

Water: 24-28°C, pH 7.8-8.5, hard alkaline; tolerant species but thrives in clean, stable conditions. Tank: 200L minimum; heavy rockwork to manage male aggression and provide female refuge. Feeding: Herbivore diet — spirulina pellets, Nori, algae wafers; occasional frozen brine shrimp acceptable. Breeding: Prolific maternal mouthbrooder; females may temporarily colour shift; brood size 15-30 eggs. Compatibility: Aggressive with conspecifics and related Melanochromis; keep with robust similar-sized mbuna.