Can Achara Catfish and Dwarf Pencilfish Live Together?

Not Recommended

Achara Catfish and Dwarf Pencilfish are not recommended as tank mates due to 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

Achara Catfish

Leiarius marmoratus

Dwarf Pencilfish

Nannostomus marginatus

🐠Family Group
Achara Catfish
Catfish
Dwarf Pencilfish
Characins
Temperament
Achara Catfish
Semi-Aggressive (6/10)
Dwarf Pencilfish
Peaceful (1/10)
Temperature
✓ Compatible
Achara Catfish
22–28°C
Dwarf Pencilfish
22–28°C
pH Range
✓ Compatible
Achara Catfish
6–7.5
Dwarf Pencilfish
4–7
Hardness (dGH)
✓ Compatible
Achara Catfish
4–15
Dwarf Pencilfish
1–10
Water Type
✓ Compatible
Achara Catfish
Freshwater Only
Dwarf Pencilfish
Freshwater Only
Flow Preference
✓ Compatible
Achara Catfish
Moderate
Dwarf Pencilfish
Low
Min Tank Volume
Combined: 1500 L
Achara Catfish
1500 L
Dwarf Pencilfish
40 L
Swimming Level
✓ Different zones
Achara Catfish
Bottom
Dwarf Pencilfish
TopMiddle
🏷️Behavior Tags
Achara Catfish
Piscivore (Eats small/nano fish)NocturnalShrimp EaterFry PredatorDigger (Disturbs Substrate)
Dwarf Pencilfish
Nano / Bite-sized (Predation Risk)Shy / Slow Moving (Easily Stressed)Jumper (Lid Required)
Stocking calculator

Can your tank handle Achara Catfish and Dwarf Pencilfish?

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.

Achara Catfish
Dwarf Pencilfish
Test both in my tank

Behaviour & Temperament

Achara Catfish is a moderately assertive species (6/10), while Dwarf Pencilfish is peaceful (1/10). This notable difference means Achara Catfish may occasionally assert dominance over Dwarf Pencilfish.

In terms of spatial distribution, Achara Catfish prefers the Bottom (Substrate) zone, whereas Dwarf Pencilfish 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.

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: Shrimp eaters may also prey on very small nano fish.

Worth noting: Achara Catfish is nocturnal and will be most active after lights-out, naturally reducing daytime encounters. Also, Dwarf Pencilfish is a known jumper, so a tight-fitting lid is essential.

Water Parameters

The safe temperature window for both species falls between 22°C and 28°C. Aim for the midpoint of this range (around 25.0°C) for optimal comfort.

Both fish can tolerate a pH between 6 and 7. Maintaining a stable value within this band is more important than hitting an exact number.

For general hardness, the shared comfort zone is 4–10 dGH. Regular testing will ensure conditions stay within this range.

Tank Setup

To house Achara Catfish and Dwarf Pencilfish together, plan for an aquarium of at least 1500 litres with a minimum length of 240 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), Smooth Gravel (Sensitive Barbels), Driftwood (Digestion/Hiding), Plants - Densely covered, Plants - Floating, Leaf Litter/Blackwater. 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.

Diet & Feeding

Feeding time deserves special attention with this pairing. Achara Catfish is a known shrimp eater and may prey on small invertebrates or nano fish like Dwarf Pencilfish.

Frequently Asked Questions

Can Achara Catfish and Dwarf Pencilfish live together?

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

What size tank do Achara Catfish and Dwarf Pencilfish need?

A minimum of 1500 litres (tank length at least 240 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 Achara Catfish and Dwarf Pencilfish together?

Keep the aquarium between 22°C and 28°C. A target of around 25.0°C sits comfortably within both species' preferred ranges.

Are Achara Catfish or Dwarf Pencilfish aggressive?

Achara Catfish is moderately assertive (6/10) and Dwarf Pencilfish is peaceful (1/10). The gap in aggression levels means the calmer fish may experience stress from the more assertive one.

What pH do Achara Catfish and Dwarf Pencilfish need?

Both species overlap in the 6–7 pH range. Consistency is key — avoid sudden swings, and test regularly to stay within this window.

Does Achara Catfish being nocturnal affect compatibility?

Achara Catfish 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 Achara Catfish during evening hours.


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