Can Clown Killifish and Ornate Bichir Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Clown Killifish and Ornate Bichir are not recommended as tank mates due to piscivorous fish will prey on nano-sized tank mates.. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Clown Killifish

Epiplatys annulatus

Ornate Bichir

Polypterus ornatipinnis

🐠Family Group
Clown Killifish
Killifish
Ornate Bichir
Oddballs
Temperament
Clown Killifish
Peaceful (2/10)
Ornate Bichir
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Clown Killifish
23–27°C
Ornate Bichir
26–30°C
pH Range
✓ Compatible
Clown Killifish
5–7
Ornate Bichir
6–8
Hardness (dGH)
✓ Compatible
Clown Killifish
1–8
Ornate Bichir
5–20
Water Type
✓ Compatible
Clown Killifish
Freshwater Only
Ornate Bichir
Freshwater Only
Flow Preference
✓ Compatible
Clown Killifish
Low
Ornate Bichir
Low
Min Tank Volume
Combined: 680 L
Clown Killifish
19 L
Ornate Bichir
680 L
Swimming Level
✓ Different zones
Clown Killifish
Top
Ornate Bichir
Bottom
🏷️Behavior Tags
Clown Killifish
Nano / Bite-sized (Predation Risk)Jumper (Lid Required)Shy / Slow Moving (Easily Stressed)Fry Predator
Ornate Bichir
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Shrimp EaterFry Predator
Stocking calculator

Can your tank handle Clown Killifish 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.

Clown Killifish
Ornate Bichir
Test both in my tank

Behaviour & Temperament

Clown Killifish is a peaceful species (2/10), while Ornate Bichir is moderately assertive (6/10). This notable difference means Ornate Bichir may occasionally assert dominance over Clown Killifish.

In terms of spatial distribution, Clown Killifish prefers the Top (Surface) zone, whereas Ornate Bichir 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 Nano / Bite-sized (Predation Risk) behaviour of one fish directly conflicts with the Piscivore (Eats small/nano fish) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Shrimp eaters may also prey on very small nano fish.

Worth noting: Ornate Bichir is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Clown Killifish 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.

Both fish can tolerate a pH between 6 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 5–8 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Clown Killifish 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: Plants - Floating, Plants - Densely covered, Leaf Litter/Blackwater, Sand (Sifters), Driftwood (Digestion/Hiding), Smooth Gravel (Sensitive Barbels). 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 Usually Fails in Practice

Clown Killifish 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 Clown Killifish and Ornate Bichir.

Diet & Feeding

Feeding time deserves special attention with this pairing. Ornate Bichir is a known shrimp eater and may prey on small invertebrates or nano fish like Clown Killifish.

Frequently Asked Questions

Can Clown Killifish 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 Clown Killifish 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 Clown Killifish 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 Clown Killifish or Ornate Bichir aggressive?

Clown Killifish is peaceful (2/10) and Ornate Bichir is moderately assertive (6/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Clown Killifish and Ornate Bichir need?

Both species overlap in the 6–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

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?
Contact the editorial team

Related Comparisons

Clown Killifish & Gardner's Killifish

·

Possible with Caution
Clown Killifish: PeacefulGardner's Killifish: Peaceful

Clown Killifish & Largereye Lampeye Killifish

·

Possible with Caution
Clown Killifish: PeacefulLargereye Lampeye Killifish: Peaceful

Clown Killifish & Lyretail Killifish

·

Ideal Tank Mates
Clown Killifish: PeacefulLyretail Killifish: Peaceful

Clown Killifish & Japanese Ricefish (Medaka)

·

Possible with Caution
Clown Killifish: PeacefulJapanese Ricefish (Medaka): Peaceful

Clown Killifish & Norman's Lampeye Killifish

·

Possible with Caution
Clown Killifish: PeacefulNorman's Lampeye Killifish: Peaceful

Clown Killifish & Rachov's Killifish (Annual)

·

Possible with Caution
Clown Killifish: PeacefulRachov's Killifish (Annual): Peaceful

Ornate Bichir & African Knifefish

·

Possible with Caution
Ornate Bichir: PeacefulAfrican Knifefish: Peaceful

Ornate Bichir & Buettikoferi Bichir

·

Possible with Caution
Ornate Bichir: PeacefulBuettikoferi Bichir: Peaceful

Ornate Bichir & Delhezi Bichir (Armored Bichir)

·

Possible with Caution
Ornate Bichir: PeacefulDelhezi Bichir (Armored Bichir): Peaceful

Ornate Bichir & Freshwater Toadfish (Prehistoric Monster Fish)

·

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

Ornate Bichir & Guinean Bichir

·

Possible with Caution
Ornate Bichir: PeacefulGuinean Bichir: Peaceful

Ornate Bichir & Marbled Bichir

·

Possible with Caution
Ornate Bichir: PeacefulMarbled Bichir: Peaceful