🌈 Threadfin Rainbow (Iriatherina werneri) – Elegant Freshwater Rainbowfish

Description: The Threadfin Rainbow (Iriatherina werneri) is one of the most delicate and graceful rainbowfish species, prized for its long flowing fins and shimmering coloration. Males develop striking, thread-like extensions on their fins, giving them a truly unique and elegant appearance. Peaceful and small in size, Threadfin Rainbows are perfect for planted community aquariums where they can display their beauty in schools.

Care Information

• Scientific Name: Iriatherina werneri
• Care Level: Moderate
• Temperament: Peaceful, schooling
• Max Size: ~2 inches (5 cm)
• Tank Size: Minimum 15–20 gallons (larger for groups)
• Diet: Omnivorous – micro pellets, flakes, live/frozen foods (daphnia, baby brine shrimp, cyclops)
• Water Parameters:
• Temperature: 74–82°F (23–28°C)
• pH: 6.0–7.5
• Hardness: Soft to moderately hard

❓ FAQ

Q: How many Threadfin Rainbows should I keep?
A: Best kept in groups of 6 or more to encourage natural shoaling and display behavior.

Q: Are they good for community tanks?
A: Yes, they are peaceful and do well with other small, non-aggressive fish.

Q: Do they need live plants?
A: While not required, they thrive and display best in heavily planted aquariums with gentle water flow.

Q: Can they be kept with shrimp?
A: Yes, they are shrimp-safe, though tiny shrimp fry may be eaten.