Threadfin Rainbowfish

Iriatherina werneri

A delicate nano rainbowfish with elaborate thread-like fins on display males.

Water

Freshwater

Temperature

75–86°F

pH

5.5–7.5

Hardness

3–12 dGH

Max size

1.8 in

Min tank

20 gal

Temperament

Peaceful

Social

Schooling (8+)

Swim level

All

Diet

Omnivore

Care level

Intermediate

Lifespan

3-4 years

Breeding

Egg-scatterer

Suitability

Common

Origin

New Guinea and northern Australia

Threadfins have tiny mouths, so offer fine foods, and they show best in a calm, planted tank without fast tankmates stealing food. Males' extended fins are spectacular when flaring.