Can Gulper Catfish and Scat (Brackish) Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Gulper Catfish and Scat (Brackish) are not recommended as tank mates due to incompatible water types. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Gulper Catfish

Asterophysus batrachus

Scat (Brackish)

Scatophagus argus

🐠Family Group
Gulper Catfish
Catfish
Scat (Brackish)
Oddballs
Temperament
Gulper Catfish
Semi-Aggressive (6/10)
Scat (Brackish)
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Gulper Catfish
24–28°C
Scat (Brackish)
20–28°C
pH Range
✓ Compatible
Gulper Catfish
6–7.5
Scat (Brackish)
7.5–8.5
Hardness (dGH)
✓ Compatible
Gulper Catfish
2–15
Scat (Brackish)
12–30
Water Type
✗ No overlap
Gulper Catfish
Freshwater Only
Scat (Brackish)
Brackish Required
Flow Preference
✓ Compatible
Gulper Catfish
Moderate
Scat (Brackish)
High
Min Tank Volume
Combined: 493 L
Gulper Catfish
250 L
Scat (Brackish)
450 L
Swimming Level
Shared: 2 zones
Gulper Catfish
BottomMiddle
Scat (Brackish)
MiddleBottom
🏷️Behavior Tags
Gulper Catfish
Piscivore (Eats small/nano fish)NocturnalShrimp EaterFry Predator
Scat (Brackish)
Plant DestroyerHyperactive / Fast SwimmerAggressive Eater (Starves shy fish)Fin Nipper
Stocking calculator

Can your tank handle Gulper Catfish and Scat (Brackish)?

Compatibility is only part of the answer. Test both fish with your real tank size, current stock, and maintenance needs to see if you have enough space and a safe stocking level before you add them.

Gulper Catfish
Scat (Brackish)
Test both in my tank

Behaviour & Temperament

Gulper Catfish is a moderately assertive species (6/10), while Scat (Brackish) is generally mild-mannered (4/10). This modest difference means Gulper Catfish may occasionally assert dominance over Scat (Brackish).

Gulper Catfish and Scat (Brackish) both frequent the Bottom (Substrate) 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.

Worth noting: Gulper Catfish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters.

Water Parameters

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 7.5 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 12–15 dGH. Regular testing will ensure conditions stay within this range.

Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.

Tank Setup

To house Gulper Catfish and Scat (Brackish) together, plan for an aquarium of at least 493 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.

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), Established Algae (Otocinclus). 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.

Why This Pairing Usually Fails in Practice

Gulper Catfish and Scat (Brackish) 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Gulper Catfish and Scat (Brackish).

Frequently Asked Questions

Can Gulper Catfish and Scat (Brackish) live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Gulper Catfish and Scat (Brackish) need?

A minimum of 493 litres (tank length at least 150 cm) is recommended. This provides enough space for both species to establish their own areas and reduces the likelihood of territorial disputes.

What water temperature is best for Gulper Catfish and Scat (Brackish) together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Gulper Catfish or Scat (Brackish) aggressive?

Gulper Catfish is moderately assertive (6/10) and Scat (Brackish) is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Gulper Catfish and Scat (Brackish) need?

Both species overlap in the 7.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Scat (Brackish) nip Gulper Catfish's fins?

Scat (Brackish) is a known fin nipper. If Gulper Catfish has long or flowing fins, there is a real risk of fin damage. Keeping Scat (Brackish) in a larger group can help redirect nipping behaviour toward conspecifics.

Does Gulper Catfish being nocturnal affect compatibility?

Gulper Catfish is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Gulper Catfish during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
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