Can Betta Macrostoma and Cuban Gar Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Not Recommended

Betta Macrostoma and Cuban Gar are not recommended as tank mates due to 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

Cuban Gar

Atractosteus tristoechus

🐠Family Group
Betta Macrostoma
Anabantoids
Cuban Gar
Oddballs
Temperament
Betta Macrostoma
Semi-Aggressive (6/10)
Cuban Gar
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Betta Macrostoma
20–25°C
Cuban Gar
22–30°C
pH Range
✗ No overlap
Betta Macrostoma
4–6
Cuban Gar
6.5–8
Hardness (dGH)
✗ No overlap
Betta Macrostoma
0–5
Cuban Gar
8–20
Water Type
✓ Compatible
Betta Macrostoma
Freshwater Only
Cuban Gar
Brackish Tolerant
Flow Preference
✓ Compatible
Betta Macrostoma
Low
Cuban Gar
Moderate
Min Tank Volume
Combined: 3785 L
Betta Macrostoma
80 L
Cuban Gar
3785 L
Swimming Level
Shared: 2 zones
Betta Macrostoma
TopMiddleBottom
Cuban Gar
TopMiddle
🏷️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)
Cuban Gar
Piscivore (Eats small/nano fish)Jumper (Lid Required)
Stocking calculator

Can your tank handle Betta Macrostoma and Cuban Gar?

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
Cuban Gar
Test both in my tank

Behaviour & Temperament

Both Betta Macrostoma and Cuban Gar are moderately assertive species with an aggression score of 6/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Betta Macrostoma and Cuban Gar both frequent the Top (Surface) 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: Betta Macrostoma is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 22°C and 25°C. Aim for the midpoint of this range (around 23.5°C) for optimal comfort.

The pH requirements of Betta Macrostoma (4–6) and Cuban Gar (6.5–8) do not overlap, making it impossible to satisfy both species simultaneously.

Hardness requirements are incompatible: Betta Macrostoma needs 0–5 dGH while Cuban Gar requires 8–20 dGH.

Tank Setup

To house Betta Macrostoma and Cuban Gar together, plan for an aquarium of at least 3785 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.

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 Cuban Gar 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 Betta Macrostoma and Cuban Gar live together?

No. This combination is not recommended. Key incompatibilities — such as critical behavioural conflicts — make cohabitation unsafe.

What size tank do Betta Macrostoma and Cuban Gar need?

A minimum of 3785 litres (tank length at least 300 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 Cuban Gar together?

Keep the aquarium between 22°C and 25°C. A target of around 23.5°C sits comfortably within both species' preferred ranges.

Are Betta Macrostoma or Cuban Gar aggressive?

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

What pH do Betta Macrostoma and Cuban Gar need?

Their pH requirements do not overlap. Betta Macrostoma prefers 4–6, while Cuban Gar needs 6.5–8. This makes them incompatible in the same water chemistry.

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?
Contact the editorial team

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