๐Ÿ  Fish Compatibility Guide

Can Harlequin Rasbora and Julii Cory Live Together?

Updated September 23, 2026 ยท FishCare AI Editorial Team

โœ… Compatible โ€” Compatibility Score: 93/100
93/100 โ€” Compatible

Harlequin Rasbora and Julii Cory Compatibility Overview

Harlequin Rasbora and Julii Cory can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.

Compatibility factors for Harlequin Rasbora and Julii Cory
FactorHarlequin RasboraJulii CoryVerdict
Temperature72โ€“81ยฐF68โ€“79ยฐFโœ… 72โ€“79ยฐF
pH Range5.5โ€“7.55.5โ€“7.5โœ… 5.5โ€“7.5
Temperamentpeacefulpeacefulโœ… Compatible
Adult Size1.75 in2.2 inโœ… Similar
Min. Group8+6+See below
Min. Tank Size20 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.

Caution Points

No major compatibility issues identified for this pair.

Species Profiles

Harlequin Rasbora โ€” Trigonostigma heteromorpha

Harlequin Rasbora and Julii Cory compatibility โ€” Harlequin Rasbora

Active mid-level schooling fish with a distinctive black triangular patch. One of the best all-around community tank fish.

โ†’ Full Harlequin Rasbora care guide

Julii Cory โ€” Corydoras julii

Harlequin Rasbora and Julii Cory compatibility โ€” Julii Cory

The Julii Cory is a popular, peaceful bottom-dweller that thrives in community tanks. With a lifespan of up to 5 years, they are suitable for beginners and experienced aquarists alike. These fish are known for their dark brown coloration with distinctive white spots and a slender, flat body shape.

โ†’ Full Julii Cory care guide

Frequently Asked Questions

Can Harlequin Rasbora live with Julii Cory?

Yes, in a well-planned setup. Harlequin Rasbora and Julii Cory can generally share an aquarium with appropriate planning. Both species prefer overlapping temperature and pH ranges. Both species are peaceful, and neither poses a major aggression risk to the other. A minimum 20-gallon tank is recommended to provide adequate territory and water volume for both species.

What tank size do I need for Harlequin Rasbora and Julii Cory together?

A minimum of 20 gallons is recommended for keeping Harlequin Rasbora and Julii Cory together. A larger tank improves water stability and reduces territorial conflict.

What temperature suits both Harlequin Rasbora and Julii Cory?

72โ€“79ยฐF โ€” inside Harlequin Rasbora's 72โ€“81ยฐF and Julii Cory's 68โ€“79ยฐF.

Is a Harlequin Rasbora aggressive toward a Julii Cory?

Harlequin Rasbora is peaceful and Julii Cory is peaceful. No major aggression issues are expected between these species.

Related Compatibility Guides

Tank Size for Harlequin Rasbora and Julii Cory

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

ScenarioTankWhen it applies
Minimum viable21 galOnly for the recommended minimum groups, mature filtration, and close monitoring.
Recommended community29 galAdds territory, swimming room, and a safer buffer for behavior.
Low-conflict setup55 galBest when keeping larger schools or reducing territorial pressure.