Threadfin Rainbow

The Threadfin Rainbowfish (Iriatherina werneri), also called the Featherfin Rainbowfish, is a stunning choice for community and planted aquariums. Native to the lush, plant-filled streams of New Guinea and Australia, this fish is known for its striking, elongated fins, especially in mature males.

Its coloration includes shades of gray-green, yellow, red, and blue, which become more vivid as the fish matures, particularly with a varied, high-quality diet. Keeping a school of six or more, with a mix of males and females, encourages the best display of colors and natural behavior. They thrive on a diet of flake foods, live, freeze-dried, or frozen foods and are compatible with aquarium plants, leaving them undisturbed.

Being a mid-to-upper-level swimmer, Threadfin Rainbowfish can occasionally jump, so it's wise to use a tank lid or maintain a lower water level. They prefer stable, clean water with plenty of plant cover, including floating plants like duckweed or hornwort, which help reduce the chance of jumping. Unlike many rainbowfish, they naturally inhabit calm, slow-moving waters and should be kept in tanks with minimal current.

Rainbowfish are popular in aquariums for their peaceful nature, resilience, and vivid colors. Unlike larger rainbowfish species, Threadfin Rainbowfish are small enough to be safely housed with dwarf shrimp and other gentle invertebrates.

Highlights of the Threadfin Rainbowfish:

• Vibrant colors and flowing fin extensions.
• Peaceful temperament, suitable for tanks with non-aggressive invertebrates.
• Hardy and adaptable to various conditions.
• Perfect for filling the middle and top levels of your aquarium.

Tank Requirements:

• Temperature: 72°–86°F (22°–30°C)
• pH: 5.0–8.0
• KH: 7–10 dKH
• Minimum tank size: 10 gallons

Care Tips:

• Diet: Omnivorous, including flake, freeze-dried, and frozen foods with both meaty and plant-based options.
• Behavior: Peaceful and schooling. Males may show mild aggression in pairs but are calm in larger groups with females.
• Size: Adults grow to about 1.2–1.6 inches (3–4 cm).
• Origin: Tank-bred, native to Indonesia, New Guinea, and Australia.

This elegant and manageable fish is an excellent choice for anyone looking to add beauty and grace to their aquarium.