Can Bucktooth Tetra (Exodon) and Peacock Eel Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Bucktooth Tetra (Exodon) and Peacock Eel are not recommended as tank mates due to eye biters attack slow-moving fish, risking permanent injury.. 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

Peacock Eel

Macrognathus siamensis

🐠Family Group
Bucktooth Tetra (Exodon)
Characins
Peacock Eel
Oddballs
Temperament
Bucktooth Tetra (Exodon)
Highly Aggressive (9/10)
Peacock Eel
Peaceful (2/10)
Temperature
✓ Compatible
Bucktooth Tetra (Exodon)
23–28°C
Peacock Eel
23–28°C
pH Range
✓ Compatible
Bucktooth Tetra (Exodon)
5.5–7.5
Peacock Eel
6.5–8
Hardness (dGH)
✓ Compatible
Bucktooth Tetra (Exodon)
1–15
Peacock Eel
5–15
Water Type
✓ Compatible
Bucktooth Tetra (Exodon)
Freshwater Only
Peacock Eel
Freshwater Only
Flow Preference
✓ Compatible
Bucktooth Tetra (Exodon)
Moderate
Peacock Eel
Low
Min Tank Volume
Combined: 200 L
Bucktooth Tetra (Exodon)
200 L
Peacock Eel
150 L
Swimming Level
✓ Different zones
Bucktooth Tetra (Exodon)
MiddleTop
Peacock Eel
Bottom
🏷️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)
Peacock Eel
Digger (Disturbs Substrate)Jumper (Lid Required)NocturnalShy / Slow Moving (Easily Stressed)Shrimp EaterFry PredatorAggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Bucktooth Tetra (Exodon) and Peacock Eel?

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.

Bucktooth Tetra (Exodon)
Peacock Eel
Test both in my tank

Behaviour & Temperament

Bucktooth Tetra (Exodon) is a highly aggressive species (9/10), while Peacock Eel is peaceful (2/10). This notable difference means Bucktooth Tetra (Exodon) may occasionally assert dominance over Peacock Eel.

Large aggression gap (7 points) between Bucktooth Tetra (Exodon) and Peacock Eel increases stress risk for the more peaceful fish.

In terms of spatial distribution, Bucktooth Tetra (Exodon) prefers the Middle (Open Water) and Top (Surface) zones, whereas Peacock Eel occupies the Bottom (Substrate) zone. Because they use different levels of the water column, territorial disputes are less likely and the tank will appear more balanced.

There is a critical concern: the Eye Biter (Attacks slow moving fish) behaviour of one fish directly conflicts with the Shy / Slow Moving (Easily Stressed) trait of the other — eye biters attack slow-moving fish, risking permanent injury..

Additional behavioural considerations to keep in mind: Aggressive fish may bully and stress shy, slow-moving species. Hyperactive swimmers can stress shy, slow-moving species through constant motion.

Worth noting: Peacock Eel is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, 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 6.5 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 5–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Bucktooth Tetra (Exodon) and Peacock Eel together, plan for an aquarium of at least 200 litres with a minimum length of 120 cm. This recommendation combines the stricter species minimums with a community-load allowance so the pairing has realistic long-term space and filtration headroom.

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), Sand (Sifters), 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.

Why This Pairing Usually Fails in Practice

Bucktooth Tetra (Exodon) and Peacock Eel are the kind of pair that can look acceptable in a shop but become a maintenance problem at home. The main risk is not a single number in the chart; it is the way incompatible behavior, water needs, or pressure on space compounds over time once both fish are established in the same tank.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Bucktooth Tetra (Exodon) and Peacock Eel.

Show 5 more tank sizes

Frequently Asked Questions

Can Bucktooth Tetra (Exodon) and Peacock Eel 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 Peacock Eel need?

A minimum of 200 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 Peacock Eel 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 Peacock Eel aggressive?

Bucktooth Tetra (Exodon) is highly aggressive (9/10) and Peacock Eel 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 Peacock Eel 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 Bucktooth Tetra (Exodon) nip Peacock Eel's fins?

Bucktooth Tetra (Exodon) is a known fin nipper. If Peacock Eel 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.

Does Peacock Eel being nocturnal affect compatibility?

Peacock Eel is most active after lights-out, which naturally reduces daytime encounters with its tank mate. This can actually be beneficial, as both fish get undisturbed time to feed and explore. Just ensure food reaches Peacock Eel during evening hours.

Editorial Review

Guidarium Editorial Desk

Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.

Last reviewed
May 7, 2026
Last updated
May 7, 2026
Issues or corrections?
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