Can Finger Fish and Piraiba Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Finger Fish and Piraiba 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

Finger Fish

Monodactylus argenteus

Piraiba

Brachyplatystoma filamentosum

🐠Family Group
Finger Fish
Oddballs
Piraiba
Catfish
Temperament
Finger Fish
Semi-Aggressive (5/10)
Piraiba
Aggressive (7/10)
Temperature
✓ Compatible
Finger Fish
24–28°C
Piraiba
24–29°C
pH Range
✓ Compatible
Finger Fish
7.5–8.5
Piraiba
6–7.5
Hardness (dGH)
✓ Compatible
Finger Fish
12–30
Piraiba
2–15
Water Type
✗ No overlap
Finger Fish
Brackish Required
Piraiba
Freshwater Only
Flow Preference
✓ Compatible
Finger Fish
Moderate
Piraiba
High
Min Tank Volume
Combined: 30000 L
Finger Fish
470 L
Piraiba
30000 L
Swimming Level
Shared: 1 zone
Finger Fish
Middle
Piraiba
MiddleBottom
🏷️Behavior Tags
Finger Fish
Hyperactive / Fast SwimmerFin NipperPlant DestroyerAggressive to same species/look-alikes
Piraiba
Piscivore (Eats small/nano fish)Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Finger Fish and Piraiba?

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.

Finger Fish
Piraiba
Test both in my tank

Behaviour & Temperament

Finger Fish is a moderately assertive species (5/10), while Piraiba is semi-aggressive (7/10). This modest difference means Piraiba may occasionally assert dominance over Finger Fish.

Finger Fish and Piraiba both frequent the 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: Piraiba is a known jumper, so a tight-fitting lid is essential.

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 Finger Fish and Piraiba together, plan for an aquarium of at least 30000 litres with a minimum length of 600 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: Smooth Gravel (Sensitive Barbels), Sand (Sifters). 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

Finger Fish and Piraiba 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.

Frequently Asked Questions

Can Finger Fish and Piraiba live together?

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

What size tank do Finger Fish and Piraiba need?

A minimum of 30000 litres (tank length at least 600 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 Finger Fish and Piraiba 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 Finger Fish or Piraiba aggressive?

Finger Fish is moderately assertive (5/10) and Piraiba is semi-aggressive (7/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Finger Fish and Piraiba 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 Finger Fish nip Piraiba's fins?

Finger Fish is a known fin nipper. If Piraiba has long or flowing fins, there is a real risk of fin damage. Keeping Finger Fish in a larger group can help redirect nipping behaviour toward conspecifics.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 7, 2026
Last updated
May 7, 2026
Issues or corrections?
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