Murray River Rainbowfish
Melanotaenia fluviatilis
The Murray River Rainbowfish (Melanotaenia fluviatilis) is a peaceful fish that's easy to keep. Give it a tank of at least 180 litres (48 US gallons), water held at 72-81°F, and a pH of 6.8-8.2. Always keep a group of at least 6 - they feel safest in numbers.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
Australia
- Australia & Oceania
Regional colours match the stocking calculator's origin map.
Murray River Rainbowfish Tank Setup
Give them a tank of at least 180 litres (48 US gallons). As open-water swimmers they care more about swimming length than height, so a longer tank is ideal. Keep the water at 72-81°F with a pH around 6.8-8.2, and avoid sudden swings. Always keep a group of at least 6 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour. They reach about 12 cm as adults, so don't be misled by the small juveniles sold in stores.
What Do Murray River Rainbowfish Eat?
They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.
Murray River Rainbowfish Tank Mates
Prefers slightly cooler end; strong swimmer The Murray River Rainbowfish is peaceful, which is the first thing to weigh up when you choose tank mates. It's a shoaling fish, so settle a group of 6 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Murray River Rainbowfish Good for Beginners?
Often recommended to beginners, but only after the tank is cycled and you can keep a proper school - not three fish in a new setup.
Murray River Rainbowfish - frequently asked questions
What size tank do Murray River Rainbowfish need?
Murray River Rainbowfish need a tank of at least 180 litres (48 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
How many Murray River Rainbowfish should I keep together?
Keep a group of at least 6. Murray River Rainbowfish are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.
What water parameters do Murray River Rainbowfish need?
Keep them at 72-81°F with a pH of 6.8-8.2, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Murray River Rainbowfish eat?
Murray River Rainbowfish are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Murray River Rainbowfish good for beginners?
Yes - Murray River Rainbowfish are a good beginner choice once the tank is fully cycled and you can keep a proper group. They are hardy but still need stable water and a school to feel secure.
Common mistakes with Murray River Rainbowfish
- Buying fewer than 6 - Murray River Rainbowfishs need a proper school to feel secure; isolated individuals hide, fail to colour up, or become stressed.
- Underestimating tank size - the minimum footprint is 180 litres (48 US gallons); impulse buying into a smaller tank leads to stress and shortened lifespan.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Fish to avoid mixing with Murray River Rainbowfish
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- OscarPredator - Oscar will eat or injure smaller tank mates
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates
