Can Bucktooth Tetra (Exodon) and Marlier's Julie Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Bucktooth Tetra (Exodon) and Marlier's Julie are not recommended as tank mates due to conflicting pH requirements. 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

Marlier's Julie

Julidochromis marlieri

🐠Family Group
Bucktooth Tetra (Exodon)
Characins
Marlier's Julie
Cichlids - African
Temperament
Bucktooth Tetra (Exodon)
Highly Aggressive (9/10)
Marlier's Julie
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Bucktooth Tetra (Exodon)
23–28°C
Marlier's Julie
23–27°C
pH Range
✗ No overlap
Bucktooth Tetra (Exodon)
5.5–7.5
Marlier's Julie
8.2–9.3
Hardness (dGH)
✓ Compatible
Bucktooth Tetra (Exodon)
1–15
Marlier's Julie
10–25
Water Type
✓ Compatible
Bucktooth Tetra (Exodon)
Freshwater Only
Marlier's Julie
Freshwater Only
Flow Preference
✓ Compatible
Bucktooth Tetra (Exodon)
Moderate
Marlier's Julie
Moderate
Min Tank Volume
Combined: 200 L
Bucktooth Tetra (Exodon)
200 L
Marlier's Julie
114 L
Swimming Level
Shared: 1 zone
Bucktooth Tetra (Exodon)
MiddleTop
Marlier's Julie
BottomMiddle
🏷️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)
Marlier's Julie
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)Fry Predator
Stocking calculator

Can your tank handle Bucktooth Tetra (Exodon) and Marlier's Julie?

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)
Marlier's Julie
Test both in my tank

Behaviour & Temperament

Bucktooth Tetra (Exodon) is a highly aggressive species (9/10), while Marlier's Julie is moderately assertive (6/10). This modest difference means Bucktooth Tetra (Exodon) may occasionally assert dominance over Marlier's Julie.

Bucktooth Tetra (Exodon) and Marlier's Julie 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.

Water Parameters

The safe temperature window for both species falls between 23°C and 27°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

The pH requirements of Bucktooth Tetra (Exodon) (5.5–7.5) and Marlier's Julie (8.2–9.3) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Bucktooth Tetra (Exodon) and Marlier's Julie 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). 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 Marlier's Julie 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 Marlier's Julie.

Show 5 more tank sizes

Frequently Asked Questions

Can Bucktooth Tetra (Exodon) and Marlier's Julie 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 Marlier's Julie 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 Marlier's Julie together?

Keep the aquarium between 23°C and 27°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Bucktooth Tetra (Exodon) or Marlier's Julie aggressive?

Bucktooth Tetra (Exodon) is highly aggressive (9/10) and Marlier's Julie is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Bucktooth Tetra (Exodon) and Marlier's Julie need?

Their pH requirements do not overlap. Bucktooth Tetra (Exodon) prefers 5.5–7.5, while Marlier's Julie needs 8.2–9.3. This makes them incompatible in the same water chemistry.

Will Bucktooth Tetra (Exodon) nip Marlier's Julie's fins?

Bucktooth Tetra (Exodon) is a known fin nipper. If Marlier's Julie 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.

How do I manage Marlier's Julie's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Marlier's Julie space to claim a territory without encroaching on the other fish's area. Adding décor that divides the tank into distinct zones works especially well.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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