Can Rummynose Rasbora and Weeksi Bichir Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 11, 2026
Not Recommended

Rummynose Rasbora and Weeksi 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

Rummynose Rasbora

Sawbwa resplendens

Weeksi Bichir

Polypterus weeksii

🐠Family Group
Rummynose Rasbora
Cyprinids
Weeksi Bichir
Oddballs
Temperament
Rummynose Rasbora
Peaceful (2/10)
Weeksi Bichir
Semi-Aggressive (6/10)
Temperature
✓ Compatible
Rummynose Rasbora
20–25°C
Weeksi Bichir
24–28°C
pH Range
✓ Compatible
Rummynose Rasbora
7.3–8.5
Weeksi Bichir
6–7.5
Hardness (dGH)
✓ Compatible
Rummynose Rasbora
10–20
Weeksi Bichir
5–15
Water Type
✓ Compatible
Rummynose Rasbora
Freshwater Only
Weeksi Bichir
Freshwater Only
Flow Preference
✓ Compatible
Rummynose Rasbora
Moderate
Weeksi Bichir
Low
Min Tank Volume
Combined: 470 L
Rummynose Rasbora
60 L
Weeksi Bichir
470 L
Swimming Level
✓ Different zones
Rummynose Rasbora
Middle
Weeksi Bichir
Bottom
🏷️Behavior Tags
Rummynose Rasbora
Nano / Bite-sized (Predation Risk)Hyperactive / Fast Swimmer
Weeksi Bichir
Piscivore (Eats small/nano fish)NocturnalJumper (Lid Required)Shrimp EaterFry Predator
Stocking calculator

Can your tank handle Rummynose Rasbora and Weeksi 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.

Rummynose Rasbora
Weeksi Bichir
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Behaviour & Temperament

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

In terms of spatial distribution, Rummynose Rasbora prefers the Middle (Open Water) zone, whereas Weeksi 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: Weeksi Bichir is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Weeksi Bichir is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 24°C and 25°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 7.3 and 7.5. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 10–15 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Rummynose Rasbora and Weeksi Bichir together, plan for an aquarium of at least 470 litres with a minimum length of 150 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 - Densely covered, Sand (Sifters), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater. 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

Rummynose Rasbora and Weeksi 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 Rummynose Rasbora and Weeksi Bichir.

Diet & Feeding

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

Frequently Asked Questions

Can Rummynose Rasbora and Weeksi Bichir live together?

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

What size tank do Rummynose Rasbora and Weeksi Bichir need?

A minimum of 470 litres (tank length at least 150 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 Rummynose Rasbora and Weeksi Bichir together?

Keep the aquarium between 24°C and 25°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Rummynose Rasbora or Weeksi Bichir aggressive?

Rummynose Rasbora is peaceful (2/10) and Weeksi 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 Rummynose Rasbora and Weeksi Bichir need?

Both species overlap in the 7.3–7.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Weeksi Bichir being nocturnal affect compatibility?

Weeksi 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 Weeksi 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
Issues or corrections?
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