Can Cardinal Tetra and Marbled Hatchetfish Live Together?

🟡Possible with Caution

Keeping Cardinal Tetra and Marbled Hatchetfish together is possible but requires caution due to potential behavioral clashes. Provide a spacious tank of at least 72 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Cardinal Tetra

Paracheirodon axelrodi

Marbled Hatchetfish

Carnegiella strigata

🐟Family Group
Cardinal Tetra
Characins
Marbled Hatchetfish
Characins
Temperament
Cardinal Tetra
Peaceful (1/10)
Marbled Hatchetfish
Peaceful (1/10)
Temperature
✓ Compatible
Cardinal Tetra
24–29°C
Marbled Hatchetfish
24–28°C
pH Range
✓ Compatible
Cardinal Tetra
4–7
Marbled Hatchetfish
5.5–7.5
Hardness (dGH)
✓ Compatible
Cardinal Tetra
1–8
Marbled Hatchetfish
1–12
Water Type
✓ Compatible
Cardinal Tetra
Freshwater Only
Marbled Hatchetfish
Freshwater Only
Flow Preference
✓ Compatible
Cardinal Tetra
Low
Marbled Hatchetfish
Low
Min Tank Volume
Combined: 72 L
Cardinal Tetra
55 L
Marbled Hatchetfish
60 L
Swimming Level
✓ Different zones
Cardinal Tetra
Middle
Marbled Hatchetfish
Top
🏷️Behavior Tags
Cardinal Tetra
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerShy / Slow Moving (Easily Stressed)
Marbled Hatchetfish
Jumper (Lid Required)Shy / Slow Moving (Easily Stressed)

Behaviour & Temperament

Both Cardinal Tetra and Marbled Hatchetfish are peaceful species with an aggression score of 1/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

In terms of spatial distribution, Cardinal Tetra prefers the Middle (Open Water) zone, whereas Marbled Hatchetfish occupies the Top (Surface) zone. 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.

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.

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 5.5 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 1–8 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Cardinal Tetra and Marbled Hatchetfish together, plan for an aquarium of at least 72 litres with a minimum length of 60 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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: Leaf Litter/Blackwater, Driftwood (Digestion/Hiding), Plants - Densely covered, Plants - Floating. 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.

Frequently Asked Questions

Can Cardinal Tetra and Marbled Hatchetfish live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 72 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Cardinal Tetra and Marbled Hatchetfish need?

A minimum of 72 litres (tank length at least 60 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 Cardinal Tetra and Marbled Hatchetfish 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 Cardinal Tetra or Marbled Hatchetfish aggressive?

Cardinal Tetra is peaceful (1/10) and Marbled Hatchetfish is peaceful (1/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Cardinal Tetra and Marbled Hatchetfish need?

Both species overlap in the 5.5–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.


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