Can Amazon Leaf Fish and Forktail Blue-eye Live Together?

🔴Not Recommended

Amazon Leaf Fish and Forktail Blue-eye are not recommended as tank mates due to conflicting pH requirements and 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

Amazon Leaf Fish

Monocirrhus polyacanthus

Forktail Blue-eye

Pseudomugil furcatus

🐠Family Group
Amazon Leaf Fish
Other
Forktail Blue-eye
Rainbowfish
Temperament
Amazon Leaf Fish
Peaceful (2/10)
Forktail Blue-eye
Peaceful (2/10)
Temperature
✓ Compatible
Amazon Leaf Fish
23–29°C
Forktail Blue-eye
24–28°C
pH Range
✗ No overlap
Amazon Leaf Fish
5–6.8
Forktail Blue-eye
7–8
Hardness (dGH)
✓ Compatible
Amazon Leaf Fish
0–8
Forktail Blue-eye
5–15
Water Type
✓ Compatible
Amazon Leaf Fish
Freshwater Only
Forktail Blue-eye
Freshwater Only
Flow Preference
✓ Compatible
Amazon Leaf Fish
Low
Forktail Blue-eye
Moderate
Min Tank Volume
Combined: 90 L
Amazon Leaf Fish
75 L
Forktail Blue-eye
55 L
Swimming Level
Shared: 2 zones
Amazon Leaf Fish
MiddleTop
Forktail Blue-eye
TopMiddle
🏷️Behavior Tags
Amazon Leaf Fish
Piscivore (Eats small/nano fish)Shrimp EaterFry PredatorShy / Slow Moving (Easily Stressed)Nocturnal
Forktail Blue-eye
Nano / Bite-sized (Predation Risk)Hyperactive / Fast SwimmerJumper (Lid Required)

Behaviour & Temperament

Both Amazon Leaf Fish and Forktail Blue-eye are peaceful species with an aggression score of 2/10. Their matching temperaments mean neither fish is likely to dominate the other in a shared aquarium.

Amazon Leaf Fish and Forktail Blue-eye both frequent the Middle (Open Water) and Top (Surface) region of the setup. This overlap can increase competition for space, so providing ample room and cover is important to keep both species comfortable.

There is a critical concern: the Piscivore (Eats small/nano fish) behaviour of one fish directly conflicts with the Nano / Bite-sized (Predation Risk) trait of the other — piscivorous fish will prey on nano-sized tank mates..

Additional behavioural considerations to keep in mind: Hyperactive swimmers can stress shy, slow-moving species through constant motion. Shrimp eaters may also prey on very small nano fish.

Worth noting: Amazon Leaf Fish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Forktail Blue-eye 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 Amazon Leaf Fish (5–6.8) and Forktail Blue-eye (7–8) do not overlap, making it impossible to satisfy both species simultaneously.

For general hardness, the shared comfort zone is 5–8 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Amazon Leaf Fish and Forktail Blue-eye together, plan for an aquarium of at least 90 litres with a minimum length of 60 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: Leaf Litter/Blackwater, Plants - Densely covered, Driftwood (Digestion/Hiding), Plants - Floating. Meeting these requirements will help both species thrive.

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

Diet & Feeding

Feeding time deserves special attention with this pairing. Amazon Leaf Fish is a known shrimp eater and may prey on small invertebrates or nano fish like Forktail Blue-eye.

Frequently Asked Questions

Can Amazon Leaf Fish and Forktail Blue-eye live together?

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

What size tank do Amazon Leaf Fish and Forktail Blue-eye need?

A minimum of 90 litres (tank length at least 60 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 Amazon Leaf Fish and Forktail Blue-eye 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 Amazon Leaf Fish or Forktail Blue-eye aggressive?

Amazon Leaf Fish is peaceful (2/10) and Forktail Blue-eye is peaceful (2/10). Their similar temperaments generally lead to a peaceful coexistence.

What pH do Amazon Leaf Fish and Forktail Blue-eye need?

Their pH requirements do not overlap. Amazon Leaf Fish prefers 5–6.8, while Forktail Blue-eye needs 7–8. This makes them incompatible in the same water chemistry.

Does Amazon Leaf Fish being nocturnal affect compatibility?

Amazon Leaf Fish 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 Amazon Leaf Fish during evening hours.


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