Can Peacock Bass Orinocensis and Wels Catfish (European Catfish) Live Together?

Both Peacock Bass Orinocensis and Wels Catfish (European Catfish) are semi-aggressive species with an aggression score of 8/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Both Peacock Bass Orinocensis and Wels Catfish (European Catfish) are highly aggressive, increasing the risk of violent confrontations.

In terms of spatial distribution, Peacock Bass Orinocensis prefers the Middle (Open Water) and Top (Surface) zones, whereas Wels Catfish (European Catfish) occupies the Bottom (Substrate) 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: Two territorial species may clash over territory, especially in smaller tanks. Two aggressive species housed together increases risk of fighting.

Worth noting: Wels Catfish (European Catfish) is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Peacock Bass Orinocensis is a known jumper, so a tight-fitting lid is essential.

There is no temperature overlap between Peacock Bass Orinocensis (26–31°C) and Wels Catfish (European Catfish) (4–25°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 6 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–15 dGH. Regular testing will ensure conditions stay within this range.

To house Peacock Bass Orinocensis and Wels Catfish (European Catfish) together, plan for an aquarium of at least 10000 litres with a minimum length of 400 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/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.

Peacock Bass Orinocensis and Wels Catfish (European Catfish) are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.