Can Blind Cave Tetra and Golden Wonder Killifish Live Together?

🟡Possible with Caution

Keeping Blind Cave Tetra and Golden Wonder Killifish together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 132 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Blind Cave Tetra

Astyanax mexicanus

Golden Wonder Killifish

Aplocheilus lineatus

🐠Family Group
Blind Cave Tetra
Characins
Golden Wonder Killifish
Killifish
Temperament
Blind Cave Tetra
Mostly Peaceful (4/10)
Golden Wonder Killifish
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Blind Cave Tetra
20–25°C
Golden Wonder Killifish
22–28°C
pH Range
✓ Compatible
Blind Cave Tetra
6.5–8
Golden Wonder Killifish
6–7.5
Hardness (dGH)
✓ Compatible
Blind Cave Tetra
8–20
Golden Wonder Killifish
5–20
Water Type
✓ Compatible
Blind Cave Tetra
Freshwater Only
Golden Wonder Killifish
Brackish Tolerant
Flow Preference
✓ Compatible
Blind Cave Tetra
Moderate
Golden Wonder Killifish
Low
Min Tank Volume
Combined: 132 L
Blind Cave Tetra
110 L
Golden Wonder Killifish
75 L
Swimming Level
✓ Different zones
Blind Cave Tetra
MiddleBottom
Golden Wonder Killifish
Top
🏷️Behavior Tags
Blind Cave Tetra
Hyperactive / Fast SwimmerFin NipperAggressive Eater (Starves shy fish)
Golden Wonder Killifish
Piscivore (Eats small/nano fish)Jumper (Lid Required)Shrimp EaterFry PredatorHyperactive / Fast Swimmer

Behaviour & Temperament

Blind Cave Tetra is a generally mild-mannered species (4/10), while Golden Wonder Killifish is moderately assertive (6/10). This modest difference means Golden Wonder Killifish may occasionally assert dominance over Blind Cave Tetra.

In terms of spatial distribution, Blind Cave Tetra prefers the Middle (Open Water) and Bottom (Substrate) zones, whereas Golden Wonder Killifish 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.

Worth noting: Golden Wonder Killifish is a known jumper, so a tight-fitting lid is essential.

To improve the chances of a peaceful coexistence in this community tank: Keep fin nippers in larger groups to distribute nipping behaviour among conspecifics rather than tank mates.

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.

Both fish can tolerate a pH between 6.5 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 8–20 dGH. Regular testing will ensure conditions stay within this range. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Blind Cave Tetra and Golden Wonder Killifish together, plan for an aquarium of at least 132 litres with a minimum length of 80 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: Smooth Gravel (Sensitive Barbels), Plants - Floating. 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.

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Frequently Asked Questions

Can Blind Cave Tetra and Golden Wonder Killifish live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 132 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Blind Cave Tetra and Golden Wonder Killifish need?

A minimum of 132 litres (tank length at least 80 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 Blind Cave Tetra and Golden Wonder Killifish 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 Blind Cave Tetra or Golden Wonder Killifish aggressive?

Blind Cave Tetra is generally mild-mannered (4/10) and Golden Wonder Killifish is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Blind Cave Tetra and Golden Wonder Killifish need?

Both species overlap in the 6.5–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Blind Cave Tetra nip Golden Wonder Killifish's fins?

Blind Cave Tetra is a known fin nipper. If Golden Wonder Killifish has long or flowing fins, there is a real risk of fin damage. Keeping Blind Cave Tetra in a larger group can help redirect nipping behaviour toward conspecifics.


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