Can Delhezi Bichir (Armored Bichir) and Dusky Millions Fish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 4, 2026
Possible with Caution

Keeping Delhezi Bichir (Armored Bichir) and Dusky Millions Fish together is possible but requires caution due to differing aggression levels. Provide a spacious tank of at least 280 litres with plenty of hiding spots to reduce stress. Monitor behaviour closely, especially during the first few weeks.


At a Glance

Delhezi Bichir (Armored Bichir)

Polypterus delhezi

Dusky Millions Fish

Phalloceros caudimaculatus

🐠Family Group
Delhezi Bichir (Armored Bichir)
Oddballs
Dusky Millions Fish
Livebearers
Temperament
Delhezi Bichir (Armored Bichir)
Semi-Aggressive (6/10)
Dusky Millions Fish
Peaceful (2/10)
Temperature
✓ Compatible
Delhezi Bichir (Armored Bichir)
24–30°C
Dusky Millions Fish
16–24°C
pH Range
✓ Compatible
Delhezi Bichir (Armored Bichir)
6–8
Dusky Millions Fish
7–8
Hardness (dGH)
✓ Compatible
Delhezi Bichir (Armored Bichir)
5–20
Dusky Millions Fish
8–20
Water Type
✓ Compatible
Delhezi Bichir (Armored Bichir)
Freshwater Only
Dusky Millions Fish
Brackish Tolerant
Flow Preference
✓ Compatible
Delhezi Bichir (Armored Bichir)
Low
Dusky Millions Fish
Low
Min Tank Volume
Combined: 280 L
Delhezi Bichir (Armored Bichir)
280 L
Dusky Millions Fish
40 L
Swimming Level
✓ Different zones
Delhezi Bichir (Armored Bichir)
Bottom
Dusky Millions Fish
TopMiddle
🏷️Behavior Tags
Delhezi Bichir (Armored Bichir)
Piscivore (Eats small/nano fish)Shrimp EaterJumper (Lid Required)Nocturnal
Dusky Millions Fish
Hyperactive / Fast SwimmerPlant DestroyerFin Nipper
Stocking calculator

Can your tank handle Delhezi Bichir (Armored Bichir) and Dusky Millions Fish?

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.

Delhezi Bichir (Armored Bichir)
Dusky Millions Fish
Test both in my tank

Behaviour & Temperament

Delhezi Bichir (Armored Bichir) is a moderately assertive species (6/10), while Dusky Millions Fish is peaceful (2/10). This notable difference means Delhezi Bichir (Armored Bichir) may occasionally assert dominance over Dusky Millions Fish.

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

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

To improve the chances of a peaceful coexistence in this community tank: A larger aquarium with ample hiding spots can help diffuse aggression and give the less dominant fish space to retreat. 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 24°C and 24°C. Aim for the midpoint of this range (around 24.0°C) for optimal comfort.

Both fish can tolerate a pH between 7 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 8–20 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Delhezi Bichir (Armored Bichir) and Dusky Millions Fish together, plan for an aquarium of at least 280 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.

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), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Plants - Densely covered, Plants - Floating, Established Algae (Otocinclus). 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. Delhezi Bichir (Armored Bichir) and Dusky Millions Fish 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 Delhezi Bichir (Armored Bichir) and Dusky Millions Fish.

Show 1 more tank size

Frequently Asked Questions

Can Delhezi Bichir (Armored Bichir) and Dusky Millions Fish live together?

They can coexist, but the pairing requires careful monitoring. Provide ample space (at least 280 litres), plenty of hiding spots, and watch for signs of stress or aggression.

What size tank do Delhezi Bichir (Armored Bichir) and Dusky Millions Fish need?

A minimum of 280 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 Delhezi Bichir (Armored Bichir) and Dusky Millions Fish together?

Keep the aquarium between 24°C and 24°C. A target of around 24.0°C sits comfortably within both species' preferred ranges.

Are Delhezi Bichir (Armored Bichir) or Dusky Millions Fish aggressive?

Delhezi Bichir (Armored Bichir) is moderately assertive (6/10) and Dusky Millions Fish is peaceful (2/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Delhezi Bichir (Armored Bichir) and Dusky Millions Fish need?

Both species overlap in the 7–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Dusky Millions Fish nip Delhezi Bichir (Armored Bichir)'s fins?

Dusky Millions Fish is a known fin nipper. If Delhezi Bichir (Armored Bichir) has long or flowing fins, there is a real risk of fin damage. Keeping Dusky Millions Fish in a larger group can help redirect nipping behaviour toward conspecifics.

Does Delhezi Bichir (Armored Bichir) being nocturnal affect compatibility?

Delhezi Bichir (Armored 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 Delhezi Bichir (Armored Bichir) during evening hours.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 4, 2026
Last updated
May 4, 2026
Issues or corrections?
Contact the editorial team

Related Comparisons

Delhezi Bichir (Armored Bichir) & African Knifefish

·

Possible with Caution
Delhezi Bichir (Armored Bichir): PeacefulAfrican Knifefish: Peaceful

Delhezi Bichir (Armored Bichir) & Buettikoferi Bichir

·

Possible with Caution
Delhezi Bichir (Armored Bichir): PeacefulBuettikoferi Bichir: Peaceful

Delhezi Bichir (Armored Bichir) & Freshwater Toadfish (Prehistoric Monster Fish)

·

Possible with Caution
Delhezi Bichir (Armored Bichir): PeacefulFreshwater Toadfish (Prehistoric Monster Fish): Peaceful

Delhezi Bichir (Armored Bichir) & Guinean Bichir

·

Possible with Caution
Delhezi Bichir (Armored Bichir): PeacefulGuinean Bichir: Peaceful

Delhezi Bichir (Armored Bichir) & Marbled Bichir

·

Possible with Caution
Delhezi Bichir (Armored Bichir): PeacefulMarbled Bichir: Peaceful

Delhezi Bichir (Armored Bichir) & Mokele-mbembe Bichir

·

Possible with Caution
Delhezi Bichir (Armored Bichir): PeacefulMokele-mbembe Bichir: Peaceful

Dusky Millions Fish & Balloon Molly

·

Possible with Caution
Dusky Millions Fish: PeacefulBalloon Molly: Peaceful

Dusky Millions Fish & Guppy

·

Possible with Caution
Dusky Millions Fish: PeacefulGuppy: Peaceful

Dusky Millions Fish & Least Killifish (Heterandria)

·

Possible with Caution
Dusky Millions Fish: PeacefulLeast Killifish (Heterandria): Peaceful

Dusky Millions Fish & Molly (Sailfin/Black/Dalmatian)

·

Possible with Caution
Dusky Millions Fish: PeacefulMolly (Sailfin/Black/Dalmatian): Peaceful

Dusky Millions Fish & Platy

·

Possible with Caution
Dusky Millions Fish: PeacefulPlaty: Peaceful

Dusky Millions Fish & Sailfin Molly

·

Possible with Caution
Dusky Millions Fish: PeacefulSailfin Molly: Peaceful