Can Blind Cave Tetra and Bucktooth Tetra (Exodon) Live Together?

🟡Possible with Caution

Keeping Blind Cave Tetra and Bucktooth Tetra (Exodon) together is possible but requires caution due to differing aggression levels. Provide a spacious tank of at least 240 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

Bucktooth Tetra (Exodon)

Exodon paradoxus

🐟Family Group
Blind Cave Tetra
Characins
Bucktooth Tetra (Exodon)
Characins
Temperament
Blind Cave Tetra
Mostly Peaceful (4/10)
Bucktooth Tetra (Exodon)
Highly Aggressive (9/10)
Temperature
✓ Compatible
Blind Cave Tetra
20–25°C
Bucktooth Tetra (Exodon)
23–28°C
pH Range
✓ Compatible
Blind Cave Tetra
6.5–8
Bucktooth Tetra (Exodon)
5.5–7.5
Hardness (dGH)
✓ Compatible
Blind Cave Tetra
8–20
Bucktooth Tetra (Exodon)
1–15
Water Type
✓ Compatible
Blind Cave Tetra
Freshwater Only
Bucktooth Tetra (Exodon)
Freshwater Only
Flow Preference
✓ Compatible
Blind Cave Tetra
Moderate
Bucktooth Tetra (Exodon)
Moderate
Min Tank Volume
Combined: 240 L
Blind Cave Tetra
110 L
Bucktooth Tetra (Exodon)
200 L
Swimming Level
Shared: 1 zone
Blind Cave Tetra
MiddleBottom
Bucktooth Tetra (Exodon)
MiddleTop
🏷️Behavior Tags
Blind Cave Tetra
Hyperactive / Fast SwimmerFin NipperAggressive Eater (Starves shy fish)
Bucktooth Tetra (Exodon)
Generally AggressiveAggressive to same species/look-alikesFin NipperPiscivore (Eats small/nano fish)Hyperactive / Fast SwimmerEye Biter (Attacks slow moving fish)Jumper (Lid Required)

Behaviour & Temperament

Blind Cave Tetra is a generally mild-mannered species (4/10), while Bucktooth Tetra (Exodon) is highly aggressive (9/10). This notable difference means Bucktooth Tetra (Exodon) may occasionally assert dominance over Blind Cave Tetra.

Blind Cave Tetra and Bucktooth Tetra (Exodon) 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.

Worth noting: Bucktooth Tetra (Exodon) 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. 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 23°C and 25°C. Aim for the midpoint of this range (around 24.0°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. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Blind Cave Tetra and Bucktooth Tetra (Exodon) together, plan for an aquarium of at least 240 litres with a minimum length of 120 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), Driftwood (Digestion/Hiding). 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 Bucktooth Tetra (Exodon) live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 240 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Blind Cave Tetra and Bucktooth Tetra (Exodon) need?

A minimum of 240 litres (tank length at least 120 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 Bucktooth Tetra (Exodon) together?

Keep the aquarium between 23°C and 25°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Blind Cave Tetra or Bucktooth Tetra (Exodon) aggressive?

Blind Cave Tetra is generally mild-mannered (4/10) and Bucktooth Tetra (Exodon) is highly aggressive (9/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Blind Cave Tetra and Bucktooth Tetra (Exodon) 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 Bucktooth Tetra (Exodon)'s fins?

Blind Cave Tetra is a known fin nipper. If Bucktooth Tetra (Exodon) 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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