Can Clown Killifish and Mbu Puffer Live Together?

Clown Killifish is a peaceful species (2/10), while Mbu Puffer is semi-aggressive (7/10). This notable difference means Mbu Puffer may occasionally assert dominance over Clown Killifish.

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

There is a critical concern: the Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Clown Killifish is a known jumper, so a tight-fitting lid is essential.

The safe temperature window for both species falls between 24°C and 27°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

Both fish can tolerate a pH between 7 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

Hardness requirements are incompatible: Clown Killifish needs 1–8 dGH while Mbu Puffer requires 10–25 dGH. An aquarium test kit is recommended for monitoring.

To house Clown Killifish and Mbu Puffer together, plan for an aquarium of at least 1800 litres with a minimum length of 240 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, Plants - Densely covered, Leaf Litter/Blackwater, Sand (Sifters), Shells (Breeding/Hiding), 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.

Feeding time deserves special attention with this pairing. Mbu Puffer is an aggressive eater that may prevent Clown Killifish from getting enough food.

Because Mbu Puffer is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Clown Killifish receives an adequate share.