Can Marlier's Julie and Ornate Bichir Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Marlier's Julie and Ornate Bichir 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

Marlier's Julie

Julidochromis marlieri

Ornate Bichir

Polypterus ornatipinnis

🐠Family Group
Marlier's Julie
Cichlids - African
Ornate Bichir
Oddballs
Temperament
Marlier's Julie
Semi-Aggressive (6/10)
Ornate Bichir
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Marlier's Julie
23–27°C
Ornate Bichir
26–30°C
pH Range
✗ No overlap
Marlier's Julie
8.2–9.3
Ornate Bichir
6–8
Hardness (dGH)
✓ Compatible
Marlier's Julie
10–25
Ornate Bichir
5–20
Water Type
✓ Compatible
Marlier's Julie
Freshwater Only
Ornate Bichir
Freshwater Only
Flow Preference
✓ Compatible
Marlier's Julie
Moderate
Ornate Bichir
Low
Min Tank Volume
Combined: 680 L
Marlier's Julie
114 L
Ornate Bichir
680 L
Swimming Level
Shared: 1 zone
Marlier's Julie
BottomMiddle
Ornate Bichir
Bottom
🏷️Behavior Tags
Marlier's Julie
Territorial (Defends specific area)Aggressive to same species/look-alikesDigger (Disturbs Substrate)Fry Predator
Ornate Bichir
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Shrimp EaterFry Predator
Stocking calculator

Can your tank handle Marlier's Julie and Ornate Bichir?

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.

Marlier's Julie
Ornate Bichir
Test both in my tank

Behaviour & Temperament

Both Marlier's Julie and Ornate Bichir are moderately assertive species with an aggression score of 6/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Marlier's Julie and Ornate Bichir both frequent the 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.

Worth noting: Ornate Bichir is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Ornate Bichir is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 26°C and 27°C. Aim for the midpoint of this range (around 26.5°C) for optimal comfort.

The pH requirements of Marlier's Julie (8.2–9.3) and Ornate Bichir (6–8) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 10–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Marlier's Julie and Ornate Bichir together, plan for an aquarium of at least 680 litres with a minimum length of 180 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: Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). 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

Marlier's Julie and Ornate Bichir 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 Marlier's Julie and Ornate Bichir.

Frequently Asked Questions

Can Marlier's Julie and Ornate Bichir live together?

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

What size tank do Marlier's Julie and Ornate Bichir need?

A minimum of 680 litres (tank length at least 180 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 Marlier's Julie and Ornate Bichir together?

Keep the aquarium between 26°C and 27°C. A target of around 26.5°C sits comfortably within both species' preferred ranges.

Are Marlier's Julie or Ornate Bichir aggressive?

Marlier's Julie is moderately assertive (6/10) and Ornate Bichir is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Marlier's Julie and Ornate Bichir need?

Their pH requirements do not overlap. Marlier's Julie prefers 8.2–9.3, while Ornate Bichir needs 6–8. This makes them incompatible in the same water chemistry.

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.

Does Ornate Bichir being nocturnal affect compatibility?

Ornate Bichir 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 Ornate Bichir 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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