Can Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye Live Together?

🔴Not Recommended

Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Bucktooth Tetra (Exodon)

Exodon paradoxus

Gertrude's Spotted Blue-eye

Pseudomugil gertrudae

🐠Family Group
Bucktooth Tetra (Exodon)
Characins
Gertrude's Spotted Blue-eye
Rainbowfish
Temperament
Bucktooth Tetra (Exodon)
Highly Aggressive (9/10)
Gertrude's Spotted Blue-eye
Peaceful (2/10)
Temperature
✓ Compatible
Bucktooth Tetra (Exodon)
23–28°C
Gertrude's Spotted Blue-eye
21–28°C
pH Range
✓ Compatible
Bucktooth Tetra (Exodon)
5.5–7.5
Gertrude's Spotted Blue-eye
6–7.5
Hardness (dGH)
✓ Compatible
Bucktooth Tetra (Exodon)
1–15
Gertrude's Spotted Blue-eye
5–15
Water Type
✓ Compatible
Bucktooth Tetra (Exodon)
Freshwater Only
Gertrude's Spotted Blue-eye
Freshwater Only
Flow Preference
✓ Compatible
Bucktooth Tetra (Exodon)
Moderate
Gertrude's Spotted Blue-eye
Moderate
Min Tank Volume
Combined: 240 L
Bucktooth Tetra (Exodon)
200 L
Gertrude's Spotted Blue-eye
38 L
Swimming Level
Shared: 2 zones
Bucktooth Tetra (Exodon)
MiddleTop
Gertrude's Spotted Blue-eye
TopMiddle
🏷️Behavior Tags
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)
Gertrude's Spotted Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator

Behaviour & Temperament

Bucktooth Tetra (Exodon) is a highly aggressive species (9/10), while Gertrude's Spotted Blue-eye is peaceful (2/10). This notable difference means Bucktooth Tetra (Exodon) may occasionally assert dominance over Gertrude's Spotted Blue-eye.

Large aggression gap (7 points) between Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye increases stress risk for the more peaceful fish.

Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye both frequent the Middle (Open Water) and Top (Surface) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Worth noting: Bucktooth Tetra (Exodon) is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 23°C and 28°C. Aim for the midpoint of this range (around 25.5°C) for optimal comfort.

Both fish can tolerate a pH between 6 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 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye 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.

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

Frequently Asked Questions

Can Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye live together?

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

What size tank do Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye 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 Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye together?

Keep the aquarium between 23°C and 28°C. A target of around 25.5°C sits comfortably within both species' preferred ranges.

Are Bucktooth Tetra (Exodon) or Gertrude's Spotted Blue-eye aggressive?

Bucktooth Tetra (Exodon) is highly aggressive (9/10) and Gertrude's Spotted Blue-eye is peaceful (2/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Bucktooth Tetra (Exodon) and Gertrude's Spotted Blue-eye need?

Both species overlap in the 6–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Bucktooth Tetra (Exodon) nip Gertrude's Spotted Blue-eye's fins?

Bucktooth Tetra (Exodon) is a known fin nipper. If Gertrude's Spotted Blue-eye has long or flowing fins, there is a real risk of fin damage. Keeping Bucktooth Tetra (Exodon) in a larger group can help redirect nipping behaviour toward conspecifics.


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