Can Marbled Hatchetfish and Peacock Cichlid (Aulonocara) Live Together?

Marbled Hatchetfish is a peaceful species (1/10), while Peacock Cichlid (Aulonocara) is moderately assertive (6/10). This notable difference means Peacock Cichlid (Aulonocara) may occasionally assert dominance over Marbled Hatchetfish.

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

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 Marbled Hatchetfish (5.5–7.5) and Peacock Cichlid (Aulonocara) (7.8–8.6) 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 Marbled Hatchetfish and Peacock Cichlid (Aulonocara) together, plan for an aquarium of at least 240 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: Plants - Floating, Leaf Litter/Blackwater, Sand (Sifters), Smooth Gravel (Sensitive Barbels). Meeting these requirements will help both species thrive.

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