Can Mexican Dwarf Crayfish (CPO) and Ornate Bichir Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 7, 2026
Not Recommended

Mexican Dwarf Crayfish (CPO) and Ornate Bichir are not recommended as tank mates due to no temperature overlap. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Mexican Dwarf Crayfish (CPO)

Cambarellus patzcuarensis

Ornate Bichir

Polypterus ornatipinnis

🐠Family Group
Mexican Dwarf Crayfish (CPO)
Invertebrates
Ornate Bichir
Oddballs
Temperament
Mexican Dwarf Crayfish (CPO)
Mostly Peaceful (4/10)
Ornate Bichir
Semi-Aggressive (6/10)
Temperature
✗ No overlap
Mexican Dwarf Crayfish (CPO)
15–25°C
Ornate Bichir
26–30°C
pH Range
✓ Compatible
Mexican Dwarf Crayfish (CPO)
6.5–8
Ornate Bichir
6–8
Hardness (dGH)
✓ Compatible
Mexican Dwarf Crayfish (CPO)
6–15
Ornate Bichir
5–20
Water Type
✓ Compatible
Mexican Dwarf Crayfish (CPO)
Freshwater Only
Ornate Bichir
Freshwater Only
Flow Preference
✓ Compatible
Mexican Dwarf Crayfish (CPO)
Low
Ornate Bichir
Low
Min Tank Volume
Combined: 680 L
Mexican Dwarf Crayfish (CPO)
19 L
Ornate Bichir
680 L
Swimming Level
Shared: 1 zone
Mexican Dwarf Crayfish (CPO)
Bottom
Ornate Bichir
Bottom
🏷️Behavior Tags
Mexican Dwarf Crayfish (CPO)
Shrimp EaterFin NipperTerritorial (Defends specific area)Hyperactive / Fast Swimmer
Ornate Bichir
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Shrimp EaterFry Predator
Stocking calculator

Can your tank handle Mexican Dwarf Crayfish (CPO) 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.

Mexican Dwarf Crayfish (CPO)
Ornate Bichir
Test both in my tank

Behaviour & Temperament

Mexican Dwarf Crayfish (CPO) is a generally mild-mannered species (4/10), while Ornate Bichir is moderately assertive (6/10). This modest difference means Ornate Bichir may occasionally assert dominance over Mexican Dwarf Crayfish (CPO).

Mexican Dwarf Crayfish (CPO) 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

There is no temperature overlap between Mexican Dwarf Crayfish (CPO) (15–25°C) and Ornate Bichir (26–30°C). This fundamental mismatch makes long-term cohabitation impractical.

Both fish can tolerate a pH between 6.5 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 6–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Mexican Dwarf Crayfish (CPO) 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), Leaf Litter/Blackwater, 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

Mexican Dwarf Crayfish (CPO) 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 Mexican Dwarf Crayfish (CPO) and Ornate Bichir.

Frequently Asked Questions

Can Mexican Dwarf Crayfish (CPO) and Ornate Bichir live together?

No. This combination is not recommended. Key incompatibilities — such as non-overlapping temperature ranges — make cohabitation unsafe.

What size tank do Mexican Dwarf Crayfish (CPO) 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 Mexican Dwarf Crayfish (CPO) and Ornate Bichir together?

Unfortunately, there is no temperature range that satisfies both species. Mexican Dwarf Crayfish (CPO) requires 15–25°C, while Ornate Bichir needs 26–30°C.

Are Mexican Dwarf Crayfish (CPO) or Ornate Bichir aggressive?

Mexican Dwarf Crayfish (CPO) is generally mild-mannered (4/10) and Ornate Bichir is moderately assertive (6/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Mexican Dwarf Crayfish (CPO) and Ornate Bichir need?

Both species overlap in the 6.5–8 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Will Mexican Dwarf Crayfish (CPO) nip Ornate Bichir's fins?

Mexican Dwarf Crayfish (CPO) is a known fin nipper. If Ornate Bichir has long or flowing fins, there is a real risk of fin damage. Keeping Mexican Dwarf Crayfish (CPO) in a larger group can help redirect nipping behaviour toward conspecifics.

How do I manage Mexican Dwarf Crayfish (CPO)'s territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Mexican Dwarf Crayfish (CPO) 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?
Contact the editorial team

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