Can Duboisi Cichlid (Tropheus) and Marbled Hatchetfish Live Together?

Duboisi Cichlid (Tropheus) is a semi-aggressive species (8/10), while Marbled Hatchetfish is peaceful (1/10). This notable difference means Duboisi Cichlid (Tropheus) may occasionally assert dominance over Marbled Hatchetfish.

Large aggression gap (7 points) between Duboisi Cichlid (Tropheus) and Marbled Hatchetfish increases stress risk for the more peaceful fish.

In terms of spatial distribution, Duboisi Cichlid (Tropheus) prefers the Middle (Open Water) and Bottom (Substrate) zones, whereas Marbled Hatchetfish occupies the Top (Surface) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Marbled Hatchetfish is a known jumper, so a tight-fitting lid is essential.

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.

The pH requirements of Duboisi Cichlid (Tropheus) (8–9) and Marbled Hatchetfish (5.5–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–12 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

To house Duboisi Cichlid (Tropheus) and Marbled Hatchetfish together, plan for an aquarium of at least 336 litres with a minimum length of 120 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

Providing a mix of open swimming space and sheltered areas with rocks, driftwood, or plants will keep both species comfortable and allow natural behaviour.

Specific environmental needs for this combination include: Sand (Sifters), Established Algae (Otocinclus), Smooth Gravel (Sensitive Barbels), Plants - Floating, Leaf Litter/Blackwater. 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.

Feeding time deserves special attention with this pairing. Duboisi Cichlid (Tropheus) is an aggressive eater that may prevent Marbled Hatchetfish from getting enough food.

Because Duboisi Cichlid (Tropheus) is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Marbled Hatchetfish receives an adequate share.