Can Brevis Shelldweller and Fly River Rainbowfish Live Together?

Reviewed by Guidarium Editorial DeskUpdated May 6, 2026
Not Recommended

Brevis Shelldweller and Fly River Rainbowfish are not recommended as tank mates due to conflicting pH requirements. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.


At a Glance

Brevis Shelldweller

Neolamprologus brevis

Fly River Rainbowfish

Melanotaenia sexlineata

🐠Family Group
Brevis Shelldweller
Cichlids - African
Fly River Rainbowfish
Rainbowfish
Temperament
Brevis Shelldweller
Semi-Aggressive (5/10)
Fly River Rainbowfish
Peaceful (2/10)
Temperature
✓ Compatible
Brevis Shelldweller
24–28°C
Fly River Rainbowfish
24–28°C
pH Range
✗ No overlap
Brevis Shelldweller
8–9
Fly River Rainbowfish
6–7.5
Hardness (dGH)
✓ Compatible
Brevis Shelldweller
10–25
Fly River Rainbowfish
4–15
Water Type
✓ Compatible
Brevis Shelldweller
Freshwater Only
Fly River Rainbowfish
Freshwater Only
Flow Preference
✓ Compatible
Brevis Shelldweller
Moderate
Fly River Rainbowfish
Moderate
Min Tank Volume
Combined: 110 L
Brevis Shelldweller
38 L
Fly River Rainbowfish
110 L
Swimming Level
✓ Different zones
Brevis Shelldweller
Bottom
Fly River Rainbowfish
TopMiddle
🏷️Behavior Tags
Brevis Shelldweller
Nano / Bite-sized (Predation Risk)Territorial (Defends specific area)Digger (Disturbs Substrate)Aggressive to same species/look-alikes
Fly River Rainbowfish
Hyperactive / Fast SwimmerJumper (Lid Required)Aggressive Eater (Starves shy fish)
Stocking calculator

Can your tank handle Brevis Shelldweller and Fly River Rainbowfish?

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.

Brevis Shelldweller
Fly River Rainbowfish
Test both in my tank

Behaviour & Temperament

Brevis Shelldweller is a moderately assertive species (5/10), while Fly River Rainbowfish is peaceful (2/10). This modest difference means Brevis Shelldweller may occasionally assert dominance over Fly River Rainbowfish.

In terms of spatial distribution, Brevis Shelldweller prefers the Bottom (Substrate) zone, whereas Fly River Rainbowfish 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: Fly River Rainbowfish 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 28°C. Aim for the midpoint of this range (around 26.0°C) for optimal comfort.

The pH requirements of Brevis Shelldweller (8–9) and Fly River Rainbowfish (6–7.5) do not overlap, making it impossible to satisfy both species simultaneously.

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

Tank Setup

To house Brevis Shelldweller and Fly River Rainbowfish together, plan for an aquarium of at least 110 litres with a minimum length of 90 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), Shells (Breeding/Hiding), Plants - Densely covered, Plants - lighly covered. 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

Brevis Shelldweller and Fly River Rainbowfish 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 Brevis Shelldweller and Fly River Rainbowfish.

Show 10 more tank sizes

Frequently Asked Questions

Can Brevis Shelldweller and Fly River Rainbowfish live together?

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

What size tank do Brevis Shelldweller and Fly River Rainbowfish need?

A minimum of 110 litres (tank length at least 90 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 Brevis Shelldweller and Fly River Rainbowfish together?

Keep the aquarium between 24°C and 28°C. A target of around 26.0°C sits comfortably within both species' preferred ranges.

Are Brevis Shelldweller or Fly River Rainbowfish aggressive?

Brevis Shelldweller is moderately assertive (5/10) and Fly River Rainbowfish is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Brevis Shelldweller and Fly River Rainbowfish need?

Their pH requirements do not overlap. Brevis Shelldweller prefers 8–9, while Fly River Rainbowfish needs 6–7.5. This makes them incompatible in the same water chemistry.

How do I manage Brevis Shelldweller's territorial behaviour?

Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Brevis Shelldweller 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.

Editorial Review

Guidarium Editorial Desk

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

Last reviewed
May 6, 2026
Last updated
May 6, 2026
Issues or corrections?
Contact the editorial team

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