Can Betta Macrostoma and Peacock Bass Orinocensis Live Together?

Betta Macrostoma is a moderately assertive species (6/10), while Peacock Bass Orinocensis is semi-aggressive (8/10). This modest difference means Peacock Bass Orinocensis may occasionally assert dominance over Betta Macrostoma.

Betta Macrostoma and Peacock Bass Orinocensis both frequent the Top (Surface) and Middle (Open Water) 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: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion. Two territorial species may clash over territory, especially in smaller tanks.

Worth noting: Betta Macrostoma is a known jumper, so a tight-fitting lid is essential.

There is no temperature overlap between Betta Macrostoma (20–25°C) and Peacock Bass Orinocensis (26–31°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 5.5 and 6. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 2–5 dGH. Regular testing will ensure conditions stay within this range.

To house Betta Macrostoma and Peacock Bass Orinocensis together, plan for an aquarium of at least 750 litres with a minimum length of 200 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: Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Floating, 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.

Betta Macrostoma and Peacock Bass Orinocensis 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.