Description
Melanotaenia wilsoni, commonly known as the Little River Rainbowfish, is a rare and highly sought-after species native to the Little River system in Cape York Peninsula, Australia. Known for its slender body shape and subtle yet elegant coloration, this peaceful rainbowfish is ideal for planted community aquariums. Males display soft iridescent hues of blue, green, and gold with reddish accents along the fins, particularly when displaying or during breeding. Due to its limited natural distribution, Melanotaenia wilsoni is prized by advanced hobbyists and conservation-minded aquarists.
Features of Little River Rainbowfish (Melanotaenia wilsoni)
• Average adult size: 7–9 cm
• Lifespan: 5–8 years in captivity
• Temperament: Peaceful and schooling
• Colour: Iridescent silver-blue with red or orange fin highlights
• Sexual dimorphism: Males are larger with brighter colours and deeper bodies
• Swimming level: Mid to upper levels
• Native habitat: Clear, slow-to-moderate flowing tropical streams
The best aquarium size for Little River Rainbowfish
A minimum tank size of 100 litres is recommended for a school of 6–8 individuals. For optimal swimming space and social behaviour, a tank of 150 litres or more is ideal. Long tanks with ample horizontal space support their active nature and natural movement.
Tank Mate Compatibility for Little River Rainbowfish
• Harlequin Rasbora
• Ember Tetra
• Panda Corydoras
• Bolivian Ram
• Kuhli Loach
Diet for Little River Rainbowfish
Melanotaenia wilsoni is omnivorous and benefits from a high-quality, varied diet. Provide premium flakes or small floating pellets as a staple, supplemented with live or frozen foods such as brine shrimp, mosquito larvae, and daphnia. Occasional vegetable matter such as spirulina flakes or blanched greens aids in digestion and colour enhancement.
Aquarium Setup Little River Rainbowfish
Aquarium Filtration
Use a high-efficiency internal or external filter with moderate flow to replicate stream-like conditions. Excellent water quality and high oxygen levels are essential for health and colouration.
Aquarium Plants
This species thrives in a densely planted environment. Use native or hardy species like Vallisneria, Cryptocoryne, and Hygrophila. Plants provide cover and mimic their natural habitat, helping to reduce stress.
Aquarium Lighting
Bright, full-spectrum lighting enhances their iridescent colours and supports plant growth. Adjustable LED lighting systems are ideal for maintaining consistent photo periods.
Aquarium Heating
Maintain water temperature between 24–28°C using a reliable heater. Stability is key for long-term health and breeding potential.
Aquarium Substrate
Fine gravel or sand works well. A natural-toned substrate enhances their coloration and supports root development for live plants.
Aquarium Decorations
Incorporate smooth stones, driftwood, and floating plants to create a natural and visually appealing aquascape. Ensure ample open swimming areas remain for their active schooling behaviour.
