Can Colombian Shark Catfish (Brackish) and Scat (Brackish) Live Together?

Colombian Shark Catfish (Brackish) is a moderately assertive species (5/10), while Scat (Brackish) is generally mild-mannered (4/10). This modest difference means Colombian Shark Catfish (Brackish) may occasionally assert dominance over Scat (Brackish).

Colombian Shark Catfish (Brackish) and Scat (Brackish) both frequent the Middle (Open Water) and 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.

To improve the chances of a peaceful coexistence in this community tank: Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

The safe temperature window for both species falls between 22°C and 28°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 and 8.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 12–30 dGH. Regular testing will ensure conditions stay within this range.

To house Colombian Shark Catfish (Brackish) and Scat (Brackish) together, plan for an aquarium of at least 529 litres with a minimum length of 150 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), Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Both species do well with high (river/stream) 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. Colombian Shark Catfish (Brackish) and Scat (Brackish) 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.