Can Ornate Bichir and Red Eye Tetra Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Possible with Caution

Keeping Ornate Bichir and Red Eye Tetra together is possible but requires caution, though some care is needed. Provide a spacious tank of at least 680 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Ornate Bichir

Polypterus ornatipinnis

Red Eye Tetra

Moenkhausia sanctaefilomenae

🐠Family Group
Ornate Bichir
Oddballs
Red Eye Tetra
Characins
Temperament
Ornate Bichir
Semi-Aggressive (6/10)
Red Eye Tetra
Mostly Peaceful (3/10)
Temperature
✓ Compatible
Ornate Bichir
26–30°C
Red Eye Tetra
22–28°C
pH Range
✓ Compatible
Ornate Bichir
6–8
Red Eye Tetra
5.5–8.5
Hardness (dGH)
✓ Compatible
Ornate Bichir
5–20
Red Eye Tetra
3–20
Water Type
✓ Compatible
Ornate Bichir
Freshwater Only
Red Eye Tetra
Freshwater Only
Flow Preference
✓ Compatible
Ornate Bichir
Low
Red Eye Tetra
Moderate
Min Tank Volume
Combined: 680 L
Ornate Bichir
680 L
Red Eye Tetra
75 L
Swimming Level
✓ Different zones
Ornate Bichir
Bottom
Red Eye Tetra
MiddleTop
🏷️Behavior Tags
Ornate Bichir
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Shrimp EaterFry Predator
Red Eye Tetra
Hyperactive / Fast SwimmerFin NipperFry PredatorPlant Destroyer
Stocking calculator

Can your tank handle Ornate Bichir and Red Eye Tetra?

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.

Ornate Bichir
Red Eye Tetra
Test both in my tank

Behaviour & Temperament

Ornate Bichir is a moderately assertive species (6/10), while Red Eye Tetra is generally mild-mannered (3/10). This modest difference means Ornate Bichir may occasionally assert dominance over Red Eye Tetra.

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

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.

To improve the chances of a peaceful coexistence in this community tank: 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 26°C and 28°C. Aim for the midpoint of this range (around 27.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 8. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Ornate Bichir and Red Eye Tetra 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.

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: Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels), Plants - Densely covered. Meeting these requirements will help both species thrive.

Both species do well with low (still water) water movement, so a standard filtration setup rated for the tank volume should suffice.

Why This Pairing Needs Extra Planning in Practice

This pairing usually fails when the tank is treated like a standard mixed community and the caution flags are ignored. Ornate Bichir and Red Eye Tetra need extra room, more cover, and closer observation during the first few weeks so small aggression, feeding, or territory issues do not snowball into a long-term problem.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Ornate Bichir and Red Eye Tetra.

Frequently Asked Questions

Can Ornate Bichir and Red Eye Tetra live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 680 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Ornate Bichir and Red Eye Tetra 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 Ornate Bichir and Red Eye Tetra together?

Keep the aquarium between 26°C and 28°C. A target of around 27.0°C sits comfortably within both species' preferred ranges.

Are Ornate Bichir or Red Eye Tetra aggressive?

Ornate Bichir is moderately assertive (6/10) and Red Eye Tetra is generally mild-mannered (3/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Ornate Bichir and Red Eye Tetra need?

Both species overlap in the 6–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Red Eye Tetra nip Ornate Bichir's fins?

Red Eye Tetra is a known fin nipper. If Ornate Bichir has long or flowing fins, there is a real risk of fin damage. Keeping Red Eye Tetra in a larger group can help redirect nipping behaviour toward conspecifics.

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 11, 2026
Last updated
May 11, 2026
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