Can Marbled Bichir and Purple Spotted Gudgeon Live Together?

Marbled Bichir is a moderately assertive species (6/10), while Purple Spotted Gudgeon is moderately assertive (5/10). This modest difference means Marbled Bichir may occasionally assert dominance over Purple Spotted Gudgeon.

Marbled Bichir and Purple Spotted Gudgeon both frequent the Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

Worth noting: Marbled Bichir is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Marbled Bichir is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Provide a significantly larger tank (at least 50% more volume than the minimum) to allow both Marbled Bichir and Purple Spotted Gudgeon to establish separate territories. Add plenty of line-of-sight breaks using driftwood, rocks, and dense planting to reduce territorial confrontations.

The safe temperature window for both species falls between 24°C and 26°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 8–15 dGH. Regular testing will ensure conditions stay within this range.

To house Marbled Bichir and Purple Spotted Gudgeon together, plan for an aquarium of at least 285 litres with a minimum length of 120 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

Because this pairing requires extra vigilance, include plenty of hiding spots — caves, driftwood, and dense plant clusters — so the less dominant fish can retreat when needed.

Specific environmental needs for this combination include: Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels), Plants - Densely covered. 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.

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Marbled Bichir and Purple Spotted Gudgeon need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.