Redfin Dwarf Rainbowfish (Melanotaenia rubrivittata)

The Redfin Dwarf Rainbowfish (Melanotaenia rubrivittata), also known as the Red-Striped Rainbowfish, is a small and colorful rainbowfish native to the rivers and streams of Papua New Guinea. Males display a striking combination of iridescent blue-green flanks with vivid red fin edges and a red lateral stripe, while females are more subdued with greenish-silver bodies.

This species grows to around 7–8 cm, making it suitable for medium aquariums and ideal as a nano-to-medium planted tank rainbowfish option. Like all melanotaeniids, it is an active schooling species that shows its best colors in groups of 6 or more, particularly when males compete for female attention with energetic displays.

Redfin Dwarf Rainbowfish prefer clean, moderately hard water with good oxygenation. They are relatively undemanding in terms of care but benefit from a varied diet and regular water changes. Their peaceful temperament makes them excellent community fish alongside other similarly-sized peaceful species.

Morning is when rainbowfish display their most vivid coloration, making them a rewarding species for the observant aquarist. They occupy the upper to middle water column and are active swimmers that appreciate open space as well as planted areas along the sides of the tank.

Water Parameters: Redfin Dwarf Rainbowfish prefer neutral to slightly alkaline, moderately hard water: pH 6.8–7.8, temperature 22–28°C, GH 8–18. They appreciate clean, well-oxygenated water. Regular water changes are important for their health and coloration.

Tank Setup: A 80-liter minimum for a group of 6. Use a fine-gravel or sandy substrate with robust plants along the sides and back — Vallisneria, Sagittaria, and Echinodorus work well. Provide open swimming space in the center. A tight-fitting lid is recommended as they can jump.

Feeding: Omnivores that accept quality flake food, micro pellets, frozen bloodworm, daphnia, and brine shrimp. Include some vegetable-based food for complete nutrition. Feed twice daily. Varied diet enhances their vivid coloration.

Tankmates: Peaceful and sociable. Good companions include other small rainbowfish, tetras, rasboras, corydoras, and peaceful dwarf cichlids. Avoid aggressive or fin-nipping species. Keep in groups of 6+ for natural behavior and color displays.

Health: Hardy once acclimated. Maintain stable water parameters and good filtration. Watch for ich and bacterial infections, which can occur with poor water quality or cold temperature fluctuations. Weekly water changes of 25–30% keep conditions optimal.