Herbert Axelrod's Rainbowfish

Melanotaenia herbertaxelrodi was described in honour of the prolific aquarium fish publisher and explorer Herbert R. Axelrod, and it is a species that does its namesake justice. Males develop a rich golden-yellow to orange body overlaid with a vivid blue-violet mid-lateral iridescent stripe that runs from behind the operculum nearly to the caudal peduncle. The dorsal and anal fins carry bright yellow margins, and the overall effect under aquarium lighting is dazzling.

Native to the Lake Tebera basin in the Southern Highlands of Papua New Guinea, this species favours cool, moderately hard, alkaline waters. It is a schooling fish that does best in groups of at least six, where competing males produce the most intense colour. Regular water changes and good filtration are essential to maintaining peak condition.

Melanotaenia herbertaxelrodi is a moderately available species through specialist importers and is well-established in hobbyist breeding programs. It spawns readily among fine-leaved plants or spawning mops when pairs or trios are well conditioned on a varied diet including live foods.

Water: pH 7.0–8.0, temperature 23–27°C, moderately hard to hard; cool, well-oxygenated conditions preferred. Tank: Minimum 100 L; dense planting along tank margins with open central swimming zone. Feeding: Quality flake, pellets; live and frozen daphnia, brine shrimp, and bloodworms for conditioning. Breeding: Free egg scatterer; spawns readily on fine plants or mops; small fry require infusoria initially. Compatibility: Peaceful community species; ideal with other New Guinean rainbowfish and similarly sized peaceful fish.