๐Ÿ  Fish Compatibility Guide

Can Black Ghost Knifefish and Pygmy Corydoras Live Together?

Updated September 23, 2026 ยท FishCare AI Editorial Team

โŒ Not Compatible โ€” Compatibility Score: 32/100
32/100 โ€” Not Compatible

Black Ghost Knifefish and Pygmy Corydoras Compatibility Overview

Black Ghost Knifefish and Pygmy Corydoras are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Review the behavior and water details before deciding whether to attempt the pairing.

Compatibility factors for Black Ghost Knifefish and Pygmy Corydoras
FactorBlack Ghost KnifefishPygmy CorydorasVerdict
Temperature73โ€“82ยฐF72โ€“79ยฐFโœ… 73โ€“79ยฐF
pH Range6.0โ€“8.06.0โ€“7.5โœ… 6.0โ€“7.5
Temperamentsemipeacefulโš ๏ธ Monitor
Adult Size18.0 in1 inโŒ 18ร— difference
Min. Group1+6+See below
Min. Tank Size100 gallons (for both species)โ€”

Compatibility Positives

A stable shared temperature range is available.
Their pH requirements overlap.
Temperament risk is relatively low when normal group sizes are maintained.

Incompatibility Reasons

The adult size gap creates a meaningful predation risk.

Species Profiles

Black Ghost Knifefish โ€” Apteronotus albifrons

Black Ghost Knifefish and Pygmy Corydoras compatibility โ€” Black Ghost Knifefish

The Black Ghost Knifefish is a unique and elegant addition to the aquarium. With a lifespan of 5-8 years, it requires a minimum tank size of 200 liters. It is a solitary fish with a low aggression level and moderate activity. Its slender body and silver-blue coloration make it a captivating sight.

โ†’ Full Black Ghost Knifefish care guide

Pygmy Corydoras โ€” Corydoras pygmaeus

Black Ghost Knifefish and Pygmy Corydoras compatibility โ€” Pygmy Corydoras

Tiny armoured catfish that school in open water as well as on the substrate. Peaceful with all non-aggressive species.

โ†’ Full Pygmy Corydoras care guide

Frequently Asked Questions

Can Black Ghost Knifefish live with Pygmy Corydoras?

Generally not recommended. Black Ghost Knifefish and Pygmy Corydoras are generally not recommended to be housed together. The adult size gap creates a meaningful predation risk. Review the behavior and water details before deciding whether to attempt the pairing.

What tank size do I need for Black Ghost Knifefish and Pygmy Corydoras together?

A minimum of 100 gallons is recommended for keeping Black Ghost Knifefish and Pygmy Corydoras together. A larger tank improves water stability and reduces territorial conflict.

What temperature suits both Black Ghost Knifefish and Pygmy Corydoras?

73โ€“79ยฐF โ€” inside Black Ghost Knifefish's 73โ€“82ยฐF and Pygmy Corydoras's 72โ€“79ยฐF.

Is a Black Ghost Knifefish aggressive toward a Pygmy Corydoras?

The adult size gap creates a meaningful predation risk.

Related Compatibility Guides

Tank Size for Black Ghost Knifefish and Pygmy Corydoras

Use the scenario that matches the actual group sizes and temperament you plan to keep.

ScenarioTankWhen it applies
Minimum viable100 galOnly for the recommended minimum groups, mature filtration, and close monitoring.
Recommended community150 galAdds territory, swimming room, and a safer buffer for behavior.
Low-conflict setup220 galBest when keeping larger schools or reducing territorial pressure.