Can Finger Fish and Red Swamp Crayfish Live Together?
Finger Fish and Red Swamp Crayfish are not recommended as tank mates due to incompatible water types. Housing these species together is likely to result in stress, health problems, or direct harm to one or both fish.
At a Glance
Can your tank handle Finger Fish and Red Swamp Crayfish?
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.
Behaviour & Temperament
Finger Fish is a moderately assertive species (5/10), while Red Swamp Crayfish is highly aggressive (9/10). This notable difference means Red Swamp Crayfish may occasionally assert dominance over Finger Fish.
In terms of spatial distribution, Finger Fish prefers the Middle (Open Water) zone, whereas Red Swamp Crayfish 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.
Worth noting: Red Swamp Crayfish 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.
Both fish can tolerate a pH between 7.5 and 8.5. Maintaining a stable value within this band is more important than hitting an exact number.
For general hardness, the shared comfort zone is 12–20 dGH. Regular testing will ensure conditions stay within this range.
Crucially, these species require different water types — one needs freshwater while the other requires brackish conditions. This is a hard barrier to keeping them together.
Tank Setup
To house Finger Fish and Red Swamp Crayfish 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: Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Leaf Litter/Blackwater, Shells (Breeding/Hiding). 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
Finger Fish and Red Swamp Crayfish 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 Finger Fish and Red Swamp Crayfish.
Frequently Asked Questions
Can Finger Fish and Red Swamp Crayfish live together?
No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.
What size tank do Finger Fish and Red Swamp Crayfish 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 Finger Fish and Red Swamp Crayfish 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 Finger Fish or Red Swamp Crayfish aggressive?
Finger Fish is moderately assertive (5/10) and Red Swamp Crayfish is highly aggressive (9/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.
What pH do Finger Fish and Red Swamp Crayfish need?
Both species overlap in the 7.5–8.5 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.
Will Finger Fish nip Red Swamp Crayfish's fins?
Finger Fish is a known fin nipper. If Red Swamp Crayfish has long or flowing fins, there is a real risk of fin damage. Keeping Finger Fish in a larger group can help redirect nipping behaviour toward conspecifics.
How do I manage Red Swamp Crayfish's territorial behaviour?
Provide line-of-sight breaks using rocks, driftwood, and dense planting. A larger tank gives Red Swamp Crayfish 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.
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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
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