Description
The Melanochromis johannii, also known as the Electric Blue Johanni, is a vibrant and aggressive Mbuna cichlid native to the rocky shorelines of Lake Malawi. This species is best known for its sexual dimorphism—males display striking electric blue and black horizontal stripes, while females and juveniles are a bright golden-yellow or orange. Popular among African cichlid enthusiasts for their colour contrast and energy, M. johannii requires a well-structured tank and experienced care to manage its territorial nature.
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Features of Melanochromis johannii
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Reaches up to 10–12 cm in length
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Males: bold electric blue body with black horizontal bars
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Females: vibrant yellow to orange, offering dramatic colour contrast
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Highly aggressive and territorial, especially in confined spaces or during breeding
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Displays typical Mbuna behaviour—rock-dwelling and substrate-foraging
The Best Aquarium Size for Melanochromis johannii
A minimum tank size of 200 litres is recommended for a small group. A larger aquarium is strongly advised if housing with other Mbuna, as this species is highly aggressive and benefits from a tank layout that allows multiple territories and visual barriers.
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Tank Mate Compatibility for Melanochromis johannii
Best kept with other aggressive Mbuna that can hold their own. Tank mates should be similar in size, temperament, and not resemble the Johanni in shape or colour to prevent excessive targeting. Suitable companions include:
Avoid mixing with peaceful fish, non-Mbuna species, or other Melanochromis to reduce hybridisation and aggression.
Diet for Melanochromis johannii
Herbivorous diet is essential to avoid health issues. Feed high-quality spirulina flakes, algae-based pellets, and supplement with blanched vegetables such as zucchini, spinach, or peas. Avoid protein-heavy foods like bloodworms, which can cause bloat.
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Aquarium Setup for Melanochromis johannii
Aquarium Filtration
Strong biological and mechanical filtration is vital due to their activity and waste output. A canister filter or high-performance internal filter is recommended.
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Aquarium Plants
Not plant-friendly—most soft or rooted plants will be uprooted. Use hardy species like Anubias or Java Fern, secured to rock or driftwood, or opt for artificial plants.
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Aquarium Lighting
Moderate to bright lighting enhances the striking coloration of both males and females.
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Aquarium Heating
Maintain a stable water temperature between 24°C and 28°C, consistent with Lake Malawi conditions.
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Aquarium Substrate
Fine sand or smooth gravel is ideal, allowing natural digging and territory marking behaviours.
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Aquarium Decorations
Use plenty of rock structures and caves to create hiding places and define territories. Inert rocks like limestone also help maintain the hard, alkaline water conditions preferred by Mbuna cichlids.
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