Can Blind Cave Tetra and Serpae Tetra Live Together?

Possible with Caution

Keeping Blind Cave Tetra and Serpae Tetra together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 110 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

Serpae Tetra

Hyphessobrycon eques

🐟Family Group
Blind Cave Tetra
Characins
Serpae Tetra
Characins
Temperament
Blind Cave Tetra
Mostly Peaceful (4/10)
Serpae Tetra
Semi-Aggressive (5/10)
Temperature
✓ Compatible
Blind Cave Tetra
20–25°C
Serpae Tetra
22–28°C
pH Range
✓ Compatible
Blind Cave Tetra
6.5–8
Serpae Tetra
5–7.5
Hardness (dGH)
✓ Compatible
Blind Cave Tetra
8–20
Serpae Tetra
2–15
Water Type
✓ Compatible
Blind Cave Tetra
Freshwater Only
Serpae Tetra
Freshwater Only
Flow Preference
✓ Compatible
Blind Cave Tetra
Moderate
Serpae Tetra
Moderate
Min Tank Volume
Combined: 110 L
Blind Cave Tetra
110 L
Serpae Tetra
75 L
Swimming Level
Shared: 2 zones
Blind Cave Tetra
MiddleBottom
Serpae Tetra
MiddleBottom
🏷️Behavior Tags
Blind Cave Tetra
Hyperactive / Fast SwimmerFin NipperAggressive Eater (Starves shy fish)
Serpae Tetra
Fin NipperHyperactive / Fast SwimmerFry PredatorAggressive to same species/look-alikes
Stocking calculator

Can your tank handle Blind Cave Tetra and Serpae Tetra?

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.

Blind Cave Tetra
Serpae Tetra
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Behaviour & Temperament

Blind Cave Tetra is a generally mild-mannered species (4/10), while Serpae Tetra is moderately assertive (5/10). This modest difference means Serpae Tetra may occasionally assert dominance over Blind Cave Tetra.

Blind Cave Tetra and Serpae Tetra both frequent the Middle (Open Water) and Bottom (Substrate) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

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 8–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Blind Cave Tetra and Serpae Tetra together, plan for an aquarium of at least 110 litres with a minimum length of 80 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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 - Densely covered. 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Blind Cave Tetra and Serpae Tetra.

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Frequently Asked Questions

Can Blind Cave Tetra and Serpae Tetra live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 110 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Blind Cave Tetra and Serpae Tetra need?

A minimum of 110 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 Serpae Tetra 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 Serpae Tetra aggressive?

Blind Cave Tetra is generally mild-mannered (4/10) and Serpae Tetra is moderately assertive (5/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Blind Cave Tetra and Serpae Tetra 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 Serpae Tetra's fins?

Blind Cave Tetra is a known fin nipper. If Serpae Tetra 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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