Can Marbled Hatchetfish and Pangasius nasutus (Long-Nosed Pangasius) Live Together?

Marbled Hatchetfish is a peaceful species (1/10), while Pangasius nasutus (Long-Nosed Pangasius) is generally mild-mannered (4/10). This modest difference means Pangasius nasutus (Long-Nosed Pangasius) may occasionally assert dominance over Marbled Hatchetfish.

In terms of spatial distribution, Marbled Hatchetfish prefers the Top (Surface) zone, whereas Pangasius nasutus (Long-Nosed Pangasius) 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Aggressive eaters may outcompete shy fish for food, leading to malnutrition.

Worth noting: Marbled Hatchetfish is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat.

The safe temperature window for both species falls between 24°C and 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

Both fish can tolerate a pH between 6.5 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 5–12 dGH. Regular testing will ensure conditions stay within this range.

To house Marbled Hatchetfish and Pangasius nasutus (Long-Nosed Pangasius) together, plan for an aquarium of at least 4000 litres with a minimum length of 300 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: Plants - Floating, Leaf Litter/Blackwater, Smooth Gravel (Sensitive Barbels), Sand (Sifters). 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 Hatchetfish and Pangasius nasutus (Long-Nosed Pangasius) 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.

Feeding time deserves special attention with this pairing. Pangasius nasutus (Long-Nosed Pangasius) is an aggressive eater that may prevent Marbled Hatchetfish from getting enough food.

Because Pangasius nasutus (Long-Nosed Pangasius) is a fast, competitive feeder, consider using sinking pellets or feeding at opposite ends of the setup to ensure Marbled Hatchetfish receives an adequate share.