Harlequin Rasbora

Trigonostigma heteromorpha

Coppery-orange body with a bold black triangle — a community-tank staple.

Water

Freshwater

Temperature

72–80°F

pH

6–7.5

Hardness

2–12 dGH

Max size

1.8 in

Min tank

15 gal

Temperament

Peaceful

Social

Schooling (8+)

Swim level

Middle

Diet

Omnivore

Care level

Beginner

Lifespan

5-6 years

Breeding

Egg-depositor

Suitability

Common

Origin

Malay Peninsula, Sumatra, Thailand

Harlequins are peaceful, durable, and striking in a school. They thrive in soft, slightly acidic water but adapt well to typical tap conditions.