Blue johanni - Melanochromis cyaneorhabdos

Scientific name: Melanochromis cyaneorhabdos

Common name: Blue johanni

Family: Cichlidae

Usual size in fish tanks: 7 - 8 cm (2.76 - 3.15 inch)

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Recommended pH range for the species: 7.4 - 8.5

Recommended water hardness (dGH): 9 - 27°N (160.71 - 482.14ppm)

0°C 32°F30°C 86°F

Recommended temperature: 23 - 27 °C (73.4 - 80.6°F)

The way how these fish reproduce: Spawning

Where the species comes from: Africa

Temperament to its own species: peaceful

Temperament toward other fish species: aggressive/territorial

Usual place in the tank: Middle levels

Food and feeding

The Blue Johanni is primarily herbivorous in the wild, so it’s important to provide a diet rich in vegetable matter to meet its nutritional needs. The best staple diet includes high-quality spirulina flakes or vegetable-based pellets. These foods offer the essential nutrients and fiber that help prevent common digestive issues such as Malawi bloat, which is a concern for many Malawi cichlids.

Supplement the diet with occasional treats of protein-rich foods like brine shrimp and bloodworms. However, be cautious not to overfeed with meaty foods, as too much protein can upset their digestive balance. Feed them an amount they can finish in about 3 minutes, twice a day. Maintaining a balanced and varied diet will ensure they remain healthy and display their vibrant colors.

Origin

The Blue Johanni (Melanochromis cyaneorhabdos) is endemic to the rocky shores of Lake Malawi in Africa. This region is known for its alkaline, hard water and diverse population of colorful cichlids. In the wild, these fish inhabit rocky crevices and caves, using them for shelter and as spawning grounds. Replicating these environmental conditions in the aquarium will help them feel more comfortable and behave naturally.

Sexing

Sexing Blue Johannis can be challenging in juvenile fish, but as they mature, differences between males and females become more apparent. Males are typically larger and more vividly colored, displaying deeper blue or even black hues with horizontal stripes along their bodies. In contrast, females are smaller and usually have a lighter, more subdued coloration, often with a paler belly. Another distinguishing feature is that males tend to have longer pelvic fins compared to females, which can help with identification during breeding periods.

Breeding

Melanochromis cyaneorhabdos are maternal mouthbrooders, which means the female takes full responsibility for protecting and incubating the eggs. Breeding often occurs in the male’s established territory, where he will court the female by showing off his vibrant colors. After the female lays her eggs on a flat surface, the male fertilizes them, and the female immediately gathers the eggs into her mouth for incubation.

The incubation period lasts about 21 days, during which the female will not eat and may hide to avoid disturbances. Once the fry are ready to be released, they are fully formed and can immediately begin to feed on crushed flakes or newly hatched brine shrimp. Providing a separate breeding tank can increase the survival rate of the fry, as they may be vulnerable to predation in a community tank. Breeding is relatively easy for these fish, but ensuring that the female is not overly harassed by the male is important.

Lifespan

The expected lifespan for Blue Johannis is up to 10 years with proper care. To help them reach this age, it is crucial to provide a stable and clean environment. Regular water changes, high-quality filtration, and a balanced diet will greatly contribute to their longevity. Maintaining a healthy tank ecosystem ensures that the fish will thrive for many years in captivity.

Tank Requirements

Blue Johannis require a tank with a minimum size of 150 liters (40 gallons) for a single male with two to three females. If you plan to keep a larger group or community, a larger tank of 200 liters (53 gallons) or more is recommended to accommodate their territorial behavior. These fish prefer hard, alkaline water with a pH range of 7.4-8.5 and a temperature between 23-27°C (73.4-80.6°F). Water hardness should be maintained between 9-27°N (160.71-482.14 ppm).

The aquarium should mimic their natural habitat, which includes plenty of rocks, caves, and hiding places. Construct rock piles to create territories and ensure there are enough hiding spots for females and subdominant males. Open swimming areas should also be provided, as these fish are active swimmers. A sandy substrate is ideal, as Blue Johannis like to dig and explore the bottom of the tank. Strong filtration is necessary to maintain excellent water quality, as these fish are sensitive to water pollutants.

Tankmates

When selecting tankmates for Blue Johannis, it’s important to choose species that can tolerate their territorial behavior. They are generally peaceful with their own species, but they can become aggressive towards other cichlids, especially those with similar colors or that invade their territory. Some suitable tankmates include:

Avoid pairing them with slow-moving or smaller fish, as they may be harassed or even harmed by the more aggressive Blue Johannis. It’s also essential to maintain a ratio of one male to multiple females to reduce male aggression. Ensure that the tank is large enough to allow each fish to establish its own territory, and provide plenty of hiding spaces to help reduce aggression among tankmates.

Short Description

The Blue Johanni (Melanochromis cyaneorhabdos) is a striking and popular cichlid species, renowned for its vibrant blue coloration and territorial nature. These fish are endemic to the rocky shores of Lake Malawi, where they use crevices and caves for shelter and breeding. In the aquarium, they require a spacious tank with plenty of hiding places and a well-maintained, alkaline water environment.

While they are relatively peaceful with their own species, they can be territorial towards other fish, particularly those that invade their space. A varied diet consisting of vegetable matter and occasional protein-rich treats will keep them healthy and vibrant. With proper care, Blue Johannis can live up to 10 years in captivity, making them a rewarding species for experienced aquarists.

Pictures

Bought by aqua-fish.net from jjphoto.dk.

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Did you know?

Air pumps are often too loud, turning them off at night is usually OK for your fish.
Activated carbon must be changed on a regular basis, otherwise it might release all toxins back to the water!
You cannot expect nocturnal fish to be playful during the day. Use moonlight lights if you’re curious what they do in tank at night.
Species like Angelfish or Black Skirt Tetras, along with many others, may lose their coloration for a few minutes when the light is turned on or off.
Except for live and frozen food, always store fish food in a dry and dark place. Never feed your fish expired food; Always check for the “best before” date!