Fly River Rainbowfish
Melanotaenia sexlineata
A rarely seen rainbowfish from Papua New Guinea's remote rainforest creeks.
About
The Fly River Rainbowfish (Melanotaenia sexlineata) is one of those species that serious rainbowfish enthusiasts get genuinely excited about, partly because of how rarely it shows up in the hobby. In the wild, it's found in a handful of small, shaded rainforest streams draining into the upper Fly River near Kiunga in Papua New Guinea. A remote and restricted range that makes it naturally uncommon in both the wild and the trade. Like other melanotaeniids, it displays the classic deep-bodied, laterally compressed shape and iridescent scaling that the family is known for, though it sits on the smaller end of the size spectrum for rainbowfish. It's a peaceful community fish that does well alongside other non-aggressive species, and it appreciates tanks with decent plant cover to mimic its shaded creek habitat. Being an egg layer, it can be bred in captivity with some patience, which is part of why dedicated rainbowfish keepers work to maintain captive populations of less common species like this one. Given its somewhat limited distribution and the specificity of its natural habitat, this fish is best suited to keepers who already have some experience with rainbowfish and can give it a stable, well-planted setup.
Similar species
Other fish you might consider
Good tank mates
Species that tend to coexist peacefully with Fly River Rainbowfish
From the same region
Share the same natural habitat. Great for a biotope-themed tank
Frequently asked questions
- How big does the Fly River Rainbowfish get?
- The Fly River Rainbowfish reaches about 1.5–3" as an adult.
- What size tank does the Fly River Rainbowfish need?
- A minimum of 25 gallons is recommended for the Fly River Rainbowfish, with more room needed for a proper group.
- What water parameters does the Fly River Rainbowfish need?
- The Fly River Rainbowfish does best with a temperature of 72–82°F, a pH of 6.8–8, hardness around 5–20 dGH.
- Is the Fly River Rainbowfish aggressive?
- The Fly River Rainbowfish is generally peaceful and suits a community tank with similarly calm tankmates.
- What does the Fly River Rainbowfish eat?
- The Fly River Rainbowfish is an omnivore. It does well on a varied diet of quality flake or pellet plus occasional frozen or live foods.
- How long does the Fly River Rainbowfish live?
- With good care, the Fly River Rainbowfish typically lives 6-8 years.