Can Altolamprologus Calvus and Fosso Cichlid (Fossorochromis rostratus) Live Together?

Altolamprologus Calvus is a moderately assertive species (5/10), while Fosso Cichlid (Fossorochromis rostratus) is moderately assertive (6/10). This modest difference means Fosso Cichlid (Fossorochromis rostratus) may occasionally assert dominance over Altolamprologus Calvus.

Altolamprologus Calvus and Fosso Cichlid (Fossorochromis rostratus) both frequent the Middle (Open Water) and Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Two territorial species may clash over territory, especially in smaller tanks.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Altolamprologus Calvus and Fosso Cichlid (Fossorochromis rostratus) to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations. A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.8 and 8.6. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 10–25 dGH. Regular testing will ensure conditions stay within this range.

To house Altolamprologus Calvus and Fosso Cichlid (Fossorochromis rostratus) together, plan for an aquarium of at least 680 litres with a minimum length of 180 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Sand (Sifters), Shells (Breeding/Hiding). Meeting these requirements will help both species thrive.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.