Can Betta Macrostoma and Finger Fish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Betta Macrostoma and Finger Fish are not recommended as tank mates due to incompatible water types and conflicting pH requirements and incompatible hardness ranges. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Betta Macrostoma

Betta macrostoma

Finger Fish

Monodactylus argenteus

🐠Family Group
Betta Macrostoma
Anabantoids
Finger Fish
Oddballs
Temperament
Betta Macrostoma
Semi-Aggressive (6/10)
Finger Fish
Semi-Aggressive (5/10)
Temperature
✓ Compatible
Betta Macrostoma
20–25°C
Finger Fish
24–28°C
pH Range
✗ No overlap
Betta Macrostoma
4–6
Finger Fish
7.5–8.5
Hardness (dGH)
✗ No overlap
Betta Macrostoma
0–5
Finger Fish
12–30
Water Type
✗ No overlap
Betta Macrostoma
Freshwater Only
Finger Fish
Brackish Required
Flow Preference
✓ Compatible
Betta Macrostoma
Low
Finger Fish
Moderate
Min Tank Volume
Combined: 470 L
Betta Macrostoma
80 L
Finger Fish
470 L
Swimming Level
Shared: 1 zone
Betta Macrostoma
TopMiddleBottom
Finger Fish
Middle
🏷️Behavior Tags
Betta Macrostoma
Piscivore (Eats small/nano fish)Shrimp EaterJumper (Lid Required)Aggressive to same species/look-alikesShy / Slow Moving (Easily Stressed)Territorial (Defends specific area)
Finger Fish
Hyperactive / Fast SwimmerFin NipperPlant DestroyerAggressive to same species/look-alikes
Stocking calculator

Can your tank handle Betta Macrostoma and Finger Fish?

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.

Betta Macrostoma
Finger Fish
Test both in my tank

Behaviour & Temperament

Betta Macrostoma is a moderately assertive species (6/10), while Finger Fish is moderately assertive (5/10). This modest difference means Betta Macrostoma may occasionally assert dominance over Finger Fish.

Betta Macrostoma and Finger Fish 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.

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Betta Macrostoma 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 25°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

The pH requirements of Betta Macrostoma (4–6) and Finger Fish (7.5–8.5) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Betta Macrostoma needs 0–5 dGH while Finger Fish requires 12–30 dGH.

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 Betta Macrostoma and Finger Fish together, plan for an aquarium of at least 470 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: Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Floating, Smooth Gravel (Sensitive Barbels). 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.

Why This Pairing Usually Fails in Practice

Betta Macrostoma and Finger Fish 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 Betta Macrostoma and Finger Fish.

Frequently Asked Questions

Can Betta Macrostoma and Finger Fish live together?

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

What size tank do Betta Macrostoma and Finger Fish need?

A minimum of 470 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 Betta Macrostoma and Finger Fish together?

Keep the aquarium between 24°C and 25°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Betta Macrostoma or Finger Fish aggressive?

Betta Macrostoma is moderately assertive (6/10) and Finger Fish is moderately assertive (5/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Betta Macrostoma and Finger Fish need?

Their pH requirements do not overlap. Betta Macrostoma prefers 4–6, while Finger Fish needs 7.5–8.5. This makes them incompatible in the same water chemistry.

Will Finger Fish nip Betta Macrostoma's fins?

Finger Fish is a known fin nipper. If Betta Macrostoma 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.

How do I manage Betta Macrostoma's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Betta Macrostoma space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 4, 2026
Last updated
May 4, 2026
Issues or corrections?
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