Can Gertrude's Spotted Blue-eye and Scat (Brackish) Live Together?

🔴Not Recommended

Gertrude's Spotted Blue-eye and Scat (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

Gertrude's Spotted Blue-eye

Pseudomugil gertrudae

Scat (Brackish)

Scatophagus argus

🐠Family Group
Gertrude's Spotted Blue-eye
Rainbowfish
Scat (Brackish)
Oddballs
Temperament
Gertrude's Spotted Blue-eye
Peaceful (2/10)
Scat (Brackish)
Mostly Peaceful (4/10)
Temperature
✓ Compatible
Gertrude's Spotted Blue-eye
21–28°C
Scat (Brackish)
20–28°C
pH Range
✓ Compatible
Gertrude's Spotted Blue-eye
6–7.5
Scat (Brackish)
7.5–8.5
Hardness (dGH)
✓ Compatible
Gertrude's Spotted Blue-eye
5–15
Scat (Brackish)
12–30
Water Type
✗ No overlap
Gertrude's Spotted Blue-eye
Freshwater Only
Scat (Brackish)
Brackish Required
Flow Preference
✓ Compatible
Gertrude's Spotted Blue-eye
Moderate
Scat (Brackish)
High
Min Tank Volume
Combined: 540 L
Gertrude's Spotted Blue-eye
38 L
Scat (Brackish)
450 L
Swimming Level
Shared: 1 zone
Gertrude's Spotted Blue-eye
TopMiddle
Scat (Brackish)
MiddleBottom
🏷️Behavior Tags
Gertrude's Spotted Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)Fry Predator
Scat (Brackish)
Plant DestroyerHyperactive / Fast SwimmerAggressive Eater (Starves shy fish)Fin Nipper

Behaviour & Temperament

Gertrude's Spotted Blue-eye is a peaceful species (2/10), while Scat (Brackish) is generally mild-mannered (4/10). This modest difference means Scat (Brackish) may occasionally assert dominance over Gertrude's Spotted Blue-eye.

Gertrude's Spotted Blue-eye and Scat (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: Gertrude's Spotted Blue-eye is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 21°C and 28°C. Aim for the midpoint of this range (around 24.5°C) for optimal comfort.

Both fish can tolerate a pH between 7.5 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 12–15 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. An aquarium test kit is recommended for monitoring.

Tank Setup

To house Gertrude's Spotted Blue-eye and Scat (Brackish) together, plan for an aquarium of at least 540 litres with a minimum length of 150 cm. This accounts for the larger species' space requirements with an additional 20 % buffer to reduce territorial tension.

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, Plants - Floating, Leaf Litter/Blackwater, Sand (Sifters), Smooth Gravel (Sensitive Barbels), Established Algae (Otocinclus). Meeting these requirements will help both species thrive.

Note a potential conflict in setup requirements: Scat (Brackish) is a plant destroyer, which conflicts with Gertrude's Spotted Blue-eye's requirement for live plants. Compromise where possible or prioritise the more critical need.

Both species do well with moderate (standard) water movement, so a standard filtration setup rated for the tank volume should suffice.

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Frequently Asked Questions

Can Gertrude's Spotted Blue-eye and Scat (Brackish) live together?

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

What size tank do Gertrude's Spotted Blue-eye and Scat (Brackish) need?

A minimum of 540 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 Gertrude's Spotted Blue-eye and Scat (Brackish) together?

Keep the aquarium between 21°C and 28°C. A target of around 24.5°C sits comfortably within both species' preferred ranges.

Are Gertrude's Spotted Blue-eye or Scat (Brackish) aggressive?

Gertrude's Spotted Blue-eye is peaceful (2/10) and Scat (Brackish) is generally mild-mannered (4/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Gertrude's Spotted Blue-eye and Scat (Brackish) need?

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

Will Scat (Brackish) nip Gertrude's Spotted Blue-eye's fins?

Scat (Brackish) is a known fin nipper. If Gertrude's Spotted Blue-eye has long or flowing fins, there is a real risk of fin damage. Keeping Scat (Brackish) in a larger group can help redirect nipping behaviour toward conspecifics.


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