Can Ajamaru Rainbowfish and Ceylon Puffer (Brackish) Live Together?

Not Recommended

Ajamaru Rainbowfish and Ceylon Puffer (Brackish) 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

Ajamaru Rainbowfish

Melanotaenia ajamaruensis

Ceylon Puffer (Brackish)

Dichotomyctere fluviatilis

🐠Family Group
Ajamaru Rainbowfish
Rainbowfish
Ceylon Puffer (Brackish)
Puffers
Temperament
Ajamaru Rainbowfish
Peaceful (2/10)
Ceylon Puffer (Brackish)
Aggressive (8/10)
Temperature
✓ Compatible
Ajamaru Rainbowfish
24–28°C
Ceylon Puffer (Brackish)
24–28°C
pH Range
✓ Compatible
Ajamaru Rainbowfish
7.2–8.5
Ceylon Puffer (Brackish)
7.5–8.5
Hardness (dGH)
✓ Compatible
Ajamaru Rainbowfish
8–20
Ceylon Puffer (Brackish)
12–30
Water Type
✗ No overlap
Ajamaru Rainbowfish
Freshwater Only
Ceylon Puffer (Brackish)
Brackish Required
Flow Preference
✓ Compatible
Ajamaru Rainbowfish
Moderate
Ceylon Puffer (Brackish)
Moderate
Min Tank Volume
Combined: 150 L
Ajamaru Rainbowfish
150 L
Ceylon Puffer (Brackish)
150 L
Swimming Level
Shared: 1 zone
Ajamaru Rainbowfish
TopMiddle
Ceylon Puffer (Brackish)
MiddleBottom
🏷️Behavior Tags
Ajamaru Rainbowfish
Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Ceylon Puffer (Brackish)
Snail EaterShrimp EaterFin NipperGenerally AggressiveAggressive to same species/look-alikesHyperactive / Fast Swimmer
Stocking calculator

Can your tank handle Ajamaru Rainbowfish and Ceylon Puffer (Brackish)?

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.

Ajamaru Rainbowfish
Ceylon Puffer (Brackish)
Test both in my tank

Behaviour & Temperament

Ajamaru Rainbowfish is a peaceful species (2/10), while Ceylon Puffer (Brackish) is semi-aggressive (8/10). This notable difference means Ceylon Puffer (Brackish) may occasionally assert dominance over Ajamaru Rainbowfish.

Large aggression gap (6 points) between Ajamaru Rainbowfish and Ceylon Puffer (Brackish) increases stress risk for the more peaceful fish.

Ajamaru Rainbowfish and Ceylon Puffer (Brackish) both frequent the Middle (Open Water) 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: Ajamaru 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.

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 Ajamaru Rainbowfish and Ceylon Puffer (Brackish) together, plan for an aquarium of at least 150 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: Plants - Densely covered, Shells (Breeding/Hiding), Sand (Sifters). 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.

Suitable Tank Sizes

Standard aquarium sizes large enough for both Ajamaru Rainbowfish and Ceylon Puffer (Brackish).

Show 9 more tank sizes

Frequently Asked Questions

Can Ajamaru Rainbowfish and Ceylon Puffer (Brackish) live together?

No. This combination is not recommended. Key incompatibilities — such as different water type needs — make cohabitation unsafe.

What size tank do Ajamaru Rainbowfish and Ceylon Puffer (Brackish) need?

A minimum of 150 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 Ajamaru Rainbowfish and Ceylon Puffer (Brackish) 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 Ajamaru Rainbowfish or Ceylon Puffer (Brackish) aggressive?

Ajamaru Rainbowfish is peaceful (2/10) and Ceylon Puffer (Brackish) is semi-aggressive (8/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Ajamaru Rainbowfish and Ceylon Puffer (Brackish) 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 Ceylon Puffer (Brackish) nip Ajamaru Rainbowfish's fins?

Ceylon Puffer (Brackish) is a known fin nipper. If Ajamaru Rainbowfish has long or flowing fins, there is a real risk of fin damage. Keeping Ceylon Puffer (Brackish) in a larger group can help redirect nipping behaviour toward conspecifics.


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