Description
Melanotaenia papuae, commonly known as the Papua Rainbowfish, is a striking and peaceful freshwater species native to the clear, fast-flowing rivers and streams of Papua New Guinea. Renowned for its brilliant iridescent scales that reflect hues of blue, green, and gold, this rainbowfish is a captivating addition to planted aquariums. Its active schooling behaviour and vibrant colouration, especially in males during breeding, make it an excellent centrepiece for community tanks.
Features of Melanotaenia papuae
• Average adult size: 8–10 cm
• Lifespan: 5–7 years in captivity
• Temperament: Peaceful and active
• Colour: Iridescent blue-green with gold or red undertones
• Sexual dimorphism: Males are more colourful and deeper-bodied
• Swimming level: Mid to upper level
• Native habitat: Fast-flowing freshwater streams with dense vegetation
The best aquarium size for Melanotaenia papuae
A minimum tank size of 120 litres is recommended for a small school of six individuals. A larger aquarium of 180 litres or more is ideal to encourage natural schooling behaviour and full colour development. Horizontal swimming space is more important than height for this species.
Tank Mate Compatibility for Melanotaenia papuae
• Neon Tetra
• Corydoras Catfish
• Rummy Nose Tetra
• Dwarf Gourami
• Cherry Barb
Diet for Melanotaenia papuae
Melanotaenia papuae is omnivorous and thrives on a varied diet. Offer a high-quality flake or micro pellet as a staple, supplemented with live or frozen foods such as daphnia, brine shrimp, and bloodworms. Vegetable matter like spirulina flakes or blanched spinach can also be added to support digestion and enhance colour.
Aquarium Setup Melanotaenia papuae
Aquarium Filtration
A strong, efficient filtration system is essential to replicate their natural flowing habitat. Use an external canister filter or internal power filter with gentle current to maintain water clarity and oxygenation.
Aquarium Plants
Heavily planted tanks with species such as Vallisneria, Java fern, and Rotala are ideal. These plants provide cover and encourage natural behaviours while enhancing the aesthetic appeal.
Aquarium Lighting
Moderate to high lighting is beneficial to bring out the rainbowfish’s reflective colours and support plant growth. LED lighting with a daylight spectrum works well.
Aquarium Heating
Maintain water temperature between 24–27°C. Use a stable and adjustable heater to prevent fluctuations that could stress the fish.
Aquarium Substrate
A fine gravel or sand substrate is suitable. Darker substrates can help intensify the fish's natural colours and contrast beautifully with planted backgrounds.
Aquarium Decorations
Use driftwood, smooth rocks, and aquatic plants to create a natural-looking aquascape. Ensure open swimming space is available across the mid and upper levels of the aquarium.
