Goldie Rainbowfish

The Goldie Rainbowfish (Melanotaenia goldiei) is one of the larger and more commonly encountered rainbowfish species from Papua New Guinea, originating from the Goldie River and surrounding lowland drainages near Port Moresby. Males develop a deep, laterally compressed body with an impressive silver-green iridescence that shifts to blue-violet depending on the angle of light, complemented by vivid red-orange finnage and yellow highlights along the scale edges.

This species is hardy and adaptable, tolerating a relatively wide range of water parameters compared to many New Guinean rainbowfish. It thrives best in slightly alkaline, moderately hard water with good oxygenation and a brisk current. Dense planting along the back and sides of the aquarium, combined with a spacious open swimming zone in the centre, brings out the best territorial displays from males.

Groups of six or more bring out the spectacular colour of competing males. Goldie Rainbowfish are completely peaceful toward other community fish of similar size and make excellent dither fish for shy species. They are free-spawning egg scatterers and will readily breed among fine-leaved plants or spawning mops if given the opportunity.

Water: Prefers slightly alkaline, moderately hard water; pH 7.0–8.0, temperature 22–28°C, GH 8–15, KH 3–8. Tank: Minimum 200 L; provide dense planting at margins with wide open mid-water swimming space and a gentle current. Feeding: Accepts high-quality flake and pellet foods readily; supplement with frozen or live daphnia, brine shrimp, and bloodworms for best colour. Breeding: Free-spawning egg scatterer; spawns among fine-leaved plants or mops; remove eggs to a separate rearing tank for best yield. Compatibility: Ideal with other medium-to-large peaceful community fish; do not house with fin-nippers or very small nano species.