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  • Threadfin AKA Featherfin Rainbowfish (Iriatherina werneri) - Tank-Raised!
  • Threadfin AKA Featherfin Rainbowfish (Iriatherina werneri) - Tank-Raised!
  • Threadfin AKA Featherfin Rainbowfish (Iriatherina werneri) - Tank-Raised!
  • Threadfin AKA Featherfin Rainbowfish (Iriatherina werneri) - Tank-Raised!

Threadfin AKA Featherfin Rainbowfish (Iriatherina werneri) - Tank-Raised!

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* For the safety of our animals, we now ship live fish exclusively via UPS Next Day Air.  If your order contains this item, you will only see UPS Next Day Air as a shipping option during checkout * 


The Threadfin Rainbowfish (Iriatherina weneri) is an excellent inhabitant for any community or planted aquarium.  Also known as the Featherfin Rainbowfish, it is native to the densely planted rivers and streams of New Guinea and Australia.  This particular rainbowfish is known for the very long, ornate rear fin extensions that mature adults (especially males) possess.
The Threadfin Rainbowfish has variable gray-green, yellow, red, and blue body coloration with bright colors that extend to its fins.  While these colors are more faint in juveniles, they intensify as the fish reaches adulthood as long as a varied diet of high-quality omnivorous foods are provided.  The best coloration can be achieved in schools of 6 or more with multiple males as well as females.  Omnivorous flake foods as well as live, freeze-dried, and frozen foods will make an excellent staple diet.  Aquarium plants will not be bothered.
As with many fish that inhabit the middle and upper areas of the aquarium, the Threadfin Rainbowfish is prone to jumping occasionally.  A hood/canopy or lower water level is recommended to ensure that this fish does not jump out of the aquarium.  The only other housing requirements for this fish are clean, stable water conditions and ample areas of cover, particularly vegetation.  Floating plants such as duckweed and hornwort are very beneficial to this strictly schooling fish and will also discourage jumping.  Unlike most rainbowfish, the threadfin rainbowfish commonly inhabits slow-moving waters such as swamps, so it should be kept in an aquarium with less turbulence.
The entire family of rainbowfish is popular in freshwater aquaria due to the generally peaceful disposition, hardiness, and beautiful coloration of its members.  While many popular rainbowfish species eventually become too large to be kept with dwarf shrimp and some other nano species, the Forktail Rainbowfish is one of a few exceptions.  Fully-grown Threadfin Rainbowfish are typically safe to keep even with adult dwarf shrimp and virtually all non-aggressive invertebrates that we offer.


What We Like About This Fish:
  • Beautiful yellow, green, red, and blue coloration with elegant fin extensions as adults
  • Peaceful disposition and appropriate size to be kept with peaceful invertebrates
  • Hardy and adaptable
  • Excellent for inhabiting the middle and top levels of the aquarium
  • Temperature:  72° - 86° F (22° - 30° C)
  • pH:  5.0 - 8.0
  • KH:  7 - 10 dKH
  • Minimum tank size:  10 gallons
  • Diet:  Omnivorous.  High-quality flake, freeze-dried and frozen foods, both meaty and plant-based.
  • Social behavior:  Peaceful, schooling.  Males can be somewhat aggressive in pairs, but not when kept in groups with several females. B est kept in schools of 6 or more. 
  • Origin:  Tank-raised, but indigenous to Indonesia, New Guinea, and Australia
  • Average adult size:  1.2 - 1.6 inches (3 - 4 cm)
  • Average purchase size:  1 inch (2.5 cm)
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