The Australian Rainbowfish (Melanotaenia fluviatilis) is a hardy, peaceful rainbowfish native to Australia, valued for its active schooling behavior and subtle silver-blue shimmer with colorful fins that intensify as the fish matures. It’s an excellent choice for community aquariums, especially in larger planted tanks with plenty of open swimming space.
Tank size: 40 gallons+
Water parameters:
Temperature: 24–28 °C (75–82 °F)
pH: 7.0–8.0
Hardness: soft to moderately hard
Social behavior:
Peaceful, schooling fish
Keep in groups of 6–10+ (male-heavy groups show best color)
Tankmates:
Other rainbowfish
Peaceful tetras
Corydoras
Small gobies or loaches
Avoid: fin-nippers or aggressive cichlids.